ApprenticeManual Plastic Piping

8/13/2019 ApprenticeManual Plastic Piping

1/147

Contents 2002 PPFA. i

PP lluumm bbiinngg A App ppr r ee nn ttiicc ee TTr r aa iinn iinngg MMaa nnuu aa llFF oor r PP llaa ss ttiicc PP iipp iinngg SS yyss ttee mm ss

Written by:

PPFA Technical Committee with

Ruth H . Boutell e Richard E. Whi te

Copyright 2002Plastic Piping Educational Foundation

800 Roosevelt Road, Building C, Suite 20

Glen Ellyn, IL 60137


2/147

Contents 2002 PPFA. ii

ForewordThis manual is intended to set out the advantages and limitations of thermoplastic materialsavailable at this time for piping applications for plumbing, heating, and piping uses. Theinformation has been obtained from the manufacturers of the products discussed, and is

intended for plumbing apprentices, system designers, installers, inspectors, and users of plastic piping systems for plumbing applications.

Disclaimer The material presented in this publication has been prepared for the general information of the reader. While the information is believed to be technically correct, neither the authors,the Plastics Pipe and Fittings Association, The Plastic Piping Educational Foundation, their officers, directors, and staff, warrant the publications suitability for any specificapplication. This manual is published as an information guideline only. It shall be theresponsibility of the readers or users of this publication to conform with the requirements

of all local, state, and federal regulations, codes, and standards.


3/147

Contents 2002 PPFA. iii

TTaa bb llee oo f f CC oo nn tt ee nn tt ss

G UIDE TO ILLUSTRATIONS .............................................................. iv

DEFINITIONS .................................................................................... V

LESSON 1: P LASTICS HISTORY AND P ERCEPTIONS .............................................. 1LESSON 2: A VAILABLE THERMOPLASTIC P IPING MATERIALS ..............................9LESSON 3: P ROPERTIES OF PLASTIC P IPING ......................................................15LESSON 4: D ETAILED DISCUSSION OF ACRYLONITRILE -B UTADIENE - S TYRENE (ABS) P LASTIC P IPING ....................................... .............25LESSON 5: D ETAILED DISCUSSION OF C HLORINATED P OLY (VINYL C HLORIDE ) (CPVC) P LASTIC P IPING .................................................................. 35LESSON 6: D ETAILED DISCUSSION OF P OLYBUTYLENE (PB) P LASTIC P IPING .47

LESSON 7: D ETAILED DISCUSSION OF P OLYETHYLENE (PE) P LASTIC P IPING .51LESSON 8: D ETAILED DISCUSSION OF C ROSS -LINKED P OLYETHYLENE (PEX) P LASTIC P IPING ................................................................................ 63LESSON 9: D ETAILED DISCUSSION OF P OLYVINYL C HLORIDE (PVC) P LASTIC P IPING ...............................................................................................69LESSON 10: P LASTIC P IPING IN FIRE R ESISTIVE C ONSTRUCTION I ................ ...85LESSON 11: P LASTIC P IPING IN FIRE R ESISTIVE C ONSTRUCTION II ...... ............89LESSON 12: M ASTER COMPARISON OF THERMOPLASTIC P IPING MATERIALS 103LESSON 13: S IZING P LASTIC P IPING FOR P LUMBING S YSTEMS .......................105LESSON 14: P LASTIC P IPING IN OTHER S YSTEMS ............................................125LESSON 15: C HEMICAL R ESISTANCE ................................................................133


4/147

Contents 2002 PPFA. iv

GG uu iidd ee ttoo IIlllluu ss tt r r aa tt iioo nn ss

Figure Title Page

4-A Cellular Core Pipe Typical Foam Core Pipe Cross-Section 25 4-B Joint Surfaces Must Be Assembled While Surfaces are Wet

and Soft 29 4-C Solvent Cement Joint Being Assembled 30 4-D Completed Solvent Cement Joint 30 4-E Elastomeric Gasket Joint DWV 31 4-F Elastomeric Gasket Joint Hub and Spigot 31 4-G Elastomeric Coupling with Coupling Clamp 32 4-H Threaded Adapter 33 5-A Dimensions of Offset Elements for Expansion/Contraction 41 7-A Standard Butt Fusion Joint 61 7-B Standard Saddle Fusion Joint 61 7-C Standard Socket Fusion Joint 61

7-D Typical Electrofusion Joint 61 7-E Standard, Stab-type Mechanical Coupling 61 8-A Placement 65 8-B Water Heater Connections 65 8-C Heating Before Attaching PEX 65 8-D Horizontal Tubing Support 65 8-E PEX Minimizes Fittings 66 8-F Typical PEX Manifolds 67 9-A Cellular Core 69 9-B Solvent Cement Joint Being Assembled 77 9-C Completed Solvent Cement Joint 77 9-D Elastomeric Gasket Joint Hub and Spigot 78 9-E Elastomeric Coupling with Coupling Clamp 79

9-F Threaded Adapter 80 11-A Excerpts from Plas t i c P ipe in F i re Res i s t ive Cons t ruc t ion 90-101 14-A Typical Construction for Radiant Tubing in a Concrete Slab 125 14-B PEX Tubing Installed Over Subfloor 126 14-C Tubing in Radiant Floor with Aluminum Heat Transfer Plates 127 14-D Typical Heating Uses of Plastic Piping 128


5/147

Contents 2002 PPFA. v

DEFINITIONS

Abbreviations and Acronyms

Plastic MaterialsABS acrylonitrile butadiene styrene

CPVC chlorinated polyvinyl chlor ide

PE polyethylene

PB polybutylene

PP polypropylene

PEX cross-linked polyethylene

PVC polyvinyl chloride

PVDF polyvinylidenefluoride

PFA polyfluoroalcoxy

PTFE polytetrafluoroethylene

Organizations

AISI American Iron and Steel InstituteANSI American National Standards Institute

ASTM American Society for Testing and Materials

AWWA American Water Works Association

CSA Canadian Standards Association

CDA Copper Development Association

NSF National Sanitation Foundation International

UL Underwriters Laboratories, Inc.

ITS Intertek Testing Services (aka Warnock Hersey, ETL)


6/147

Contents 2002 PPFA. vi

ISO International Standards Organization

PPFA Plastic Pipe and Fitting Association

PPI Plastics Pipe Institute

UniBell Uni-Bell PVC Pipe Association

air admittance valveOne-way valve designed to allow air to enter the plumbing drainage system whennegative pressures develop in the piping system. The device shall close by gravityand seal the vent terminal at zero differential pressure (no flow conditions) andunder positive internal pressures. The purpose of an air admittance valve is to

provide a method of allowing air to enter the plumbing drainage system without theuse of a vent extended to open air and to prevent sewer gases from escaping into a

building.

brineA water-salt solution; also, a solution of water and an anti-freeze material used as aheat transfer agent in geothermal, ice rink, snow melting, or other systems whichrequire fluid temperatures near or below freezing.

coefficient of linear thermal expansionThe change in a unit length of a material caused by a unit change in temperature.

flexural strengthThe strength of a plastic material in bending. It is expressed as the tensile stress of the outermost fibers of a test sample bent to a specified deformation.

hydrostatic design stress (HDS)The estimated maximum tensile stress the material is capable of withstandingcontinuously with a high degree of certainty that failure of the pipe will not occur.This stress is circumferential when internal hydrostatic pressure is applied.

impact strengthThe ability of a material to resist fracture as a result of an impact.

modulus of elasticity (tensile)The ratio of the unit stress to the unit elongation due to a tensile stress, in a materialthat deforms elastically.

permeationThe migration of a fluid (liquid or gas) through the pipe wall.


7/147

Contents 2002 PPFA. vii

P IPE DIMENSION S YSTEMSIPS (Iron Pipe Size)

An OD (outside diameter) controlled dimensioning system developed by the steel

pipe industry. Pipes are designated by their "nominal size" which are approximatelythe pipe ID (inside diameter). IPS OD pipe is made in both Schedule 40 and 80wall dimensions and SDR wall dimensions. The tables contain the pertinentdimensions plus the ASTM Standard number. (See Plastic Pipe Wall Thicknessfor SDR, DR and SIDR terms.)

Sewer Pipe SizeAn OD controlled dimensioning system developed by the plastic pipe industry.Pipes are designated by their nominal size (approximate ID). Several SDR or DR controlled wall thicknesses are available for different use conditions.

CTS (Copper Tube Size)An OD controlled dimensioning system developed by the copper tube industry.The tubes are designated by nominal size, and the true OD is in each case thenominal size plus 1/8-inch. Various SDR and DR wall thicknesses are available,and they all change the ID.

ID ControlledA tube and pipe dimensioning system in which IDs are established and then anywall thickness increases or decreases change the OD. This system was developedfor use with insert fittings. All ID controlled products use the SDR or DR wallthickness concept. All the standards based on ID-controlled pipe or tube include

(SIDR-PR) in the title.

piping system life cycle costThe total cost of materials, installation, maintenance, and operation of a pipingsystem over the life of the system.

piping system life cycle cost (annual)The piping system life cycle cost divided by the years of service of the pipingsystem.

plastic (noun)A material that contains as an essential ingredient an organic substance of largemolecular weight, is solid in its finished state, and at some state in its manufactureor in its processing into finished articles, can be shaped by flow. Like metals,many plastic piping materials exhibit a wide range of physical properties andcharacteristics. Properties of plastics differ depending on the organic structure of the base polymer(s) and, to a large degree, on the quantity and type of resinadditives.


8/147

Contents 2002 PPFA. viii

plastic (adjective )A modifier which indicates that the noun being modified is made of, consists of, or

pertains to plastic.

plastic pipe wall thickness

ScheduleThis is one IPS (Iron Pipe Size - see above) system of dimensioning pipe wallthickness. They match the wall thicknesses of the corresponding steel pipeschedules. Sch 40, 80, and in some cases, Sch 120 are most often used.

SDR (Standard Dimension Ratio)A wall thickness dimensioning system developed by the plastic pipe industry. For a given SDR number, the ratio between the pipe OD and the wall thickness is held

constant for all sizes. Therefore, for a given SDR, the pressure rating for alldiameters is the same, provided the material is the same. In the SDR system theratios increase in 25 percent increments.

SIDR (Standard Inside Diameter Dimension Ratio)A wall thickness dimension system developed by the plastic pipe industry. For agiven SIDR number, the ratio between the pipe ID and the wall thickness isconstant for all sizes. Therefore, the pressure rating for all pipe sizes is constant(with the same SIDR and the same material). For a given pipe size, the pipe ODchanges as the SIDR changes. As in the SDR system, the SIDR ratios increase inabout 25 percent steps.

DR (Dimension Ratio)The DRs are also pipe-OD-to-wall-thickness ratios, but they fall outside thestandardized series that represent 25 percent changes.

Plumbing Codes Model plumbing codes, sponsored by associations of building and plumbing codeofficials or others, are the basis for most of the thousands of state and local codesin this country. The following organizations and their model plumbing codesaccept the use of plastic piping and fittings:

National Plumbing Code Building Officials and CodeAdministrators International (BOCA)

Uniform Plumbing Code International Association of Plumbing andMechanical Officials (IAPMO)

International Plumbing Code (ICC) International Codes CouncilStandard Plumbing Code Southern Building Code Congress

International (SBCCI)One and Two Family Dwelling Code Council of American Building Officials


9/147

Contents 2002 PPFA. ix

National Standard Plumbing Code Plumbing, Heating, Cooling Contractors National Association

ANSI A40, Safety Requirementsfor Plumbing Accredited Standards Committee A40

NFPA 501, Standard for Manufactured Housing National Fire Protection Association

ICC/ANSI 2.0-1998 ( Formerly CABO Manufactured Housing ConstructionSafety Standard ) International Codes Council

polymerA relatively large heavy molecule made up of one or more types of monomer unitsthat are permanently joined. Examples are PE, PB, PVC, ABS, CPVC.

specific gravityThe ratio of the density of a material to the density of water at standardtemperature.

support combustionIf a specimen that has been ignited with a flame continues to burn after the flamehas been removed, it is said to support combustion.

tensile strengthThe maximum pulling force a specimen will resist.

thermal conductivityA measure of the ability of a material to transfer heat by conduction.

thermoplasticOne of the two basic types of plastic materials. Thermoplastics soften when heatedand harden when cooled. Thermoplastics can be repeatedly softened/hardened. Inthe softened state the material can be shaped into products by injection molding or extrusion. All of the following plastics are thermoplastics : ABS, CPVC, PE, PP,PB, PVC, PVDF, PFA, and PTFE.

thermoset

One of the two basic types of plastic materials. Thermoset plastic, when cured byapplication of heat or by chemical reaction, changes into a substantially infusibleand insoluble product. A good analogy of thermosetting resins would be a hard-

boiled egg. Once a hard-boiled egg is formed, reheating will not melt and reformthe egg.

PEX is an example of a thermoset. PEX material starts with a thermoplastic (PE), but once it is cross-linked, it becomes a thermoset.


10/147

Contents 2002 PPFA. x

water absorptionThe ability of a material to absorb waterthe percent change in weight of amaterial immersed in water under defined time and temperature conditions.


11/147

Plumbing Apprentice Training Manual for Plastic Piping Systems Lesson 1

Lesson 1 2002 PPFA. 1Click here to return to Table of Contents

LLee ss ss oo nn 11::PP llaa ss ttiicc ss HHiiss ttoo r r yy aa nn dd PP ee r r cc ee pp tt iioo nn ss

G ENERAL DESCRIPTION OF PLASTICSPlastics can be divided into two general types:

1. Thermoplastics, which can be softened by the application of heat2. Thermosets, which cannot be softened by the application of heat

H ISTORY OF PLASTIC MATERIALSThe plastic industry can trace its beginning to the scarcity of ivory in the

manufacturing of billiard balls. John Wesley Hyatt, a creative chemist, mixed pyroxylin (aderivative of cotton) and nitric acid with camphor to form a product he called celluloid, a

thermoset category plastic material.Like so many other technological discoveries, there was little advancement untilwar created a need for alternative materials. Many of todays plastics polyvinylchloride (PVC), polyethylene (PE), and reinforced plastics were developed during and

just before World War II. Some were introduced into piping systems in the 1930s.In the United States, plastic piping systems obtained wide acceptance in the late

1950s and early 1960s. Since then plastic pipe usage has increased at an astounding rate.Water mains, hot and cold water distribution, drain, waste, and vent (DWV), sewer,

gas distribution, irrigation, conduit, fire sprinkler and process piping are the major marketsfor plastic piping systems throughout the world. Underground piping makes up the largest

part of the market.

C HEMICAL , MECHANICAL , AND ELECTRICAL BACKGROUNDThe wide range of properties of carbon, as it is seen in organic chemicals, accounts

for the great number of plastic materials. Carbon is the common element in polymer chains, but other elements are necessary to obtain the chemical structures of plastics.Hydrogen, oxygen, nitrogen, chlorine, fluorine, and occasionally other elements, such assulfur and silicon, are used to obtain the wide range of properties found in plastic pipingmaterials.

The nature of the molecules and polymer chains make plastics highly resistant tochemical attack by most products encountered in the home, office, and factory. Theorganic chemicals in plastic pipe, however, do not withstand the energy in ultraviolet rays,

which is why most manufacturers incorporate a shielding pigment in the plastic formula or call for protection of pipe from UV exposure.The following mechanical properties are broadly characteristic of most plastic

materials used for piping applications: Resistance to corrosion Adequate strength for many piping applications Flexibility (that is, modulus of elasticity) about ten-times that of steel Relatively soft when compared to metals


12/147

Lesson 1 Plastic Piping Educational Association

2 Lesson 1 2002 PPFA.Click here to return to Table of Contents.

Lighter than metals, easier to handle Reduced impact resistance at low temperatures (below 35 F) Strength and hardness decrease as temperatures increase Thermal expansion of plastics is about eight times that of steel

F LAMMABILITY AND ELECTRICAL PROPERTIESMost, but not all, plastics will burn in the presence of a flame. Some of these will

not continue burning if the ignition source is removed. See Lesson 10 for a more detaileddiscussion.

Most plastic materials are inherently safe if used in and around electric circuits because of the low conductivity of plastics. Plastics cannot be used as electrical groundssince they are non-conductors. Several plastics are used as insulators.

P LASTIC PIPE SIZING AND TERMSAs the new mater ial in the piping industry, plastics adopted many of the metal

piping sizing systems and developed some of its own. Pipe sizing systems can be dividedinto two categories:

1. OD Outside Diameter Controlled2. ID Inside Diameter Controlled

The joining system to be used depends on whether the pipe is OD or ID controlled.In the OD controlled system, normally couplings or sockets join to the outer

surface of the pipe. The ID controlled pipe or tube uses insert fittings. For OD controlled pipe an outside diameter is established for each nominal pipe size and all wall thicknesschanges needed for different pressure ratings affect the inside diameter.

IPS (iron pipe size) pipes with schedule walls are OD controlled and have beenused in plumbing for many years.

Many of the first plastic pipes were made to the metal pipe IPS Sch 40 and 80dimensions (see ASTM D 1527 for ABS, D 1785 for PVC, D 2104 for PE and F 441 for CPVC).

Another OD controlled system is the CTS (Copper Tube Size) system in which theoutside diameter is the nomi nal size + i nches. Some plastic tubing standards (D 2666 andD 2737) have the term tubing in their title and others (D 2846, D 3309, and F 877) haveH ot and Cold Water Di str ibution Systems in the title.

If you inspect Table 3-B, Pressure Ratings, for any of the plastic pipe IPS Schedulewall standards, you will see that for Sch 40 pipe each size has a different pressure ratingand the ratings decrease as the pipe size increases. The same is also true for Sch 80 pipeand even Sch 120 pipe. In order to provide pipes with an equal pressure rating over thewhole range of sizes, the plastic pipe industry developed the SDR-PR (StandardDimension Ratio Pressure Rating) system. For examples of this, see the Pressure ratingtables of ASTM D 2241 for PVC, D 2282 for ABS, D 3035 for PE and F 442 for CPVC.These are all IPS OD pipes with SDR - PR wall thicknesses rather than Schedule wallthicknesses.

While some non-pressure piping is IPS - OD Sch 40 product (see D 2661 for ABSDWV and D 2665 for PVC DWV) there is provision for the PVC Sch 40 pipe to be dual


13/147



marked with both D 1785 and D 2665. This enables the supply house to carry product thatcan be used for both pressure and DWV systems. L ook for the marki ng on the pipe. Do not assume that al l Sch 40 pipe qual if ies for u se as pressur e pipe. There is Sch 40 (F 628 AB S and F 891 PVC) cell ul ar core pipe that does not carr y any pressur e rating.

Sewer pipe sizes are also OD controlled but they have smaller ODs than the IPS

pipes. Sewer pipe is made from several materials (ABS, PE, and PVC) over a range of sizes and ASTM D 3034 even includes three different DR wall thicknesses.In addition to the ASTM standards, there are American Water Works Association

(AWWA) standards for both PVC and PE pipe. AWWA C900 pipe (4 inches through 12inches) is OD controlled but utilizes the cast iron/ductile iron pressure pipe ODs andassigns different safety factor/pressure ratings even though they refer to the DR (dimensionratio) wall thickness system. Note the differences in the table below for PVC pipe madefrom PVC materials having a 200 psi HDS (hydrostatic design stress).

TABLE 1-A: P RESSURE R ATINGS VS PRESSURE CLASSASTM SDR AND PRESSURE RATINGS AWWA DR AND PRESSURE CLASSES

SDR PRESSURE RATING DR PRESSURECLASS

26 160 psi 25 100 psi

21 200 psi 18 150 psi

17 250 psi 14 200 psi

This comparison shows that even though AWWA DR 14 pipe has heavier wallsthan SDR 17 pipe, it has a lower pressure class. Therefore, we see that pressur e ratin g and pressure class are not equivalent terms. Both systems use the SDR/DR wall thicknessapproach so that all sizes of DR 18 pipe made from PVC carry a 150 psi pressure classmarking.

Connections between ID controlled pipe and OD controlled pipe must be done withthe proper adapter fittings to ensure that joint leaks do not occur. There are only a fewASTM Standards for ID controlled plastic piping, fully identified in their titles (see belowfor examples).

D 2239 Polyethylene (PE) Plastic Pipe (SIDR-PR) Based on Controlled InsideDiameter

D 2662 Polybutylene (PB) Plastic Pipe (SIDR-PR) Based on Controlled InsideDiameter

This is an introductory overview of the most widely used plastic piping products,standards, sizing systems, and terms used to identify any particular piping product. Theinformation provided is correct, but does not include a variety of exceptions that prove the ru le . For example, there are communications duct sizes, water well casings in a wholeseries of sizes, plus profile wall sewer and culvert pipes that are not included here.


14/147



ADVANTAGES OF PLASTIC PIPING

a CORROSION RESISTANCE

Plastics are not conductive and are therefore immune to galvanic or electrolyticerosion. Because plastics are corrosion resistant, plastic pipe can be buried in acidic,

alkaline, wet or dry soils, and protective coatings are not required.

a CHEMICAL RESISTANCE

The variety of materials available allows a wide range of chemical solutions to behandled successfully by plastic piping.

a LOW THERMAL CONDUCTIVITYAll plastic piping materials have low thermal conductance properties. This feature

maintains more uniform temperatures when transporting fluids in plastic than in metal piping. Low thermal conductivity of the wall of plastic piping may eliminate or reducegreatly the need for pipe insulation to control sweating.

a FLEXIBILITY

In general, thermoplastic piping is relatively flexible as compared to metal piping.This facilitates use of efficient installation techniques. Some of the more flexible materialsallow for coiling, which permits long pipe runs with a minimum number of joints. Themore rigid materials are typically made into 10 foot or 20-foot pipe lengths. Pipe size isalso a factor in coiling and bending both rigid and flexible materials.

Water mains and sewers made of plastic piping can be deflected to match the curvealignment of streets and rights-of-way.

In order to avoid putting excessive strain on pipe fittings or joints when plastic is to be bent or deflected, consult the manufacturers instructions.

a LOW FRICTION LOSSBecause the interior surface of plastic piping is generally very smooth, less power

may be required to transmit fluids in plastic piping compared with other piping systems.Furthermore, the excellent corrosion resistance of plastics means that the low friction losscharacteristic will not change over time.

a LONG TERM PERFORMANCEOwing to the relative chemical inertness and the minimal effects of internal and

external corrosion, there is very little change in the physical characteristics of plastic piping over dozens of years. Examinations of pipe samples taken from some systems have

shown no measurable degradation after 25 years of service.a LIGHT WEIGHT

Most plastic piping systems are on the order of one-sixth the weight of steel piping.This feature means lower costs in many ways: lower freight charges, less manpower,simpler hoisting and rigging equipment, etc. This characteristic has allowed some uniquecost-saving installation procedures in several applications.


15/147


Lesson 2. 2002 PPFA.Click here to return to Table of Contents.

9

LLee ss ss oo nn 22::AAvv aa iillaa bb llee TThh ee r r mm oo pp llaa ss ttiicc PP iipp iinn ggMMaa ttee r r iiaa llss

The variety of applications for plastics piping is quite diverse. Generally, theseinstallations and the prevailing standards can be broken down into two groups. These arenon-pressure systems and pressurized systems. A brief discussion of the types of materialsand prevailing industry standards for each of these two groups will be presented in the

paragraphs, which follow.

R IGID AND FLEXIBLE PIPESABS, CPVC, and PVC pipe are generally referred to as rigid, and are typically

available in 10 foot and 20 foot straight lengths.PE, PB, PEX and PP materials are referred to as flexible, and are available in coilsof various lengths. In many cases, special coil lengths can be ordered for tubing that is to

be placed in radiant heat floor slabs, snow-melting slabs, or geothermal ground loops.These special-order coils assure minimum waste and enable designs in which no joints aremade within the slab.

There are exceptions to these general classifications, however. Besides being soldin coils, PE and PEX pipe are also available in 20 foot and, sometimes, 40-foot straightlengths. CPVC and PVC pipes are also available in coils in smaller sizes.

NON -PRESSURE APPLICATIONSBesides offering low installed costs, plastic pipe is attractive for non-pressure

applications (DWV and sewer) because the smooth inner walls assure high gravity flowrates and minimize the chances of developing stoppages. Plastic sewer pipes have adequatestrength for earth loads and high chemical resistance which means long life when used for sewer installations.

ABS, PVC, PE, and PP plastic pipe materials are used for these applications. Thereare separate ASTM standards for each plastic pipe based on material, dimensioningsystem, application, and (sometimes) sizing. They are listed in the lessons that follow inthis book.

P RESSURE APPLICATIONSPlastic pressure piping is used for many industrial processes, in heating and cooling

systems, fire protection installations, gas distribution, and for water supply anddistribution. Plastic piping materials that have a pressure rating Hydrostatic Design Basisin accordance with ASTM D 2837 are published by the Plastics Pipe Institute in TR-4.

Potable water applications include cold water services from wells or water mainsup to the building as well as hot and cold water distribution piping within buildings. The

piping for hot and cold water distribution systems is also tested to 150 psi at 210 F for at


16/147

Lesson 2 Plastic Piping Educational Foundation


10

least 48 hours to assure that the system can withstand these conditions which relate to the pressure and/or temperature of water heater relief valves when operating.

All plastic pressure pipe standards have 73 F pressure ratings and this is printed onthe pipe. In addition, certain plastic pipe materials and some of the pipe standards are rated

for higher temperatures. Some CPVC, PB, and PEX piping standards have been developedspecifically for hot and cold water distribution systems and most plumbing codes allow for use of these products in water distribution systems.

NOTE: The pressure rated plastic pipes that have only a 73 F rating are notapproved by codes for use in the cold water portions of the hot andcold water distribution systems.

The reason for this prohibition is based on the fact that hot and coldwater piping is installed simultaneously and the need to be certainthat a piping rated for use with cold water only is not used by

mistake in the hot water portion.

SURGE PRESSURE (WATER HAMMER )In dealing with pressure piping you will find these terms:

Gauge pressure The line pressure in the system, and it will tend to befairly constant when there is no flow or steady flow.

Surge pressure Change in pressure which occurs whenever change inflow occurs. It can be either positive or negative.

Water hammer An extreme form of surge pressure. For example, turf irrigation systems can have significant and frequent cyclic surge pressures.

One of the most common examples of water hammer can be found when line pressure and flow rate are high and a valve in the water supply line closes quickly. Typicalexamples are solenoid valves on laundry machines or dishwashers. The best protectionagainst water hammer in the first case is to size the supply line to solenoid valves(dishwashers and laundry machines) so that the velocity in the line to the valve is notexcessive. A second method of protection is to install a water hammer arrester as close as

possible to the quick-operating valve. Although air chambers are often used, they have been shown to lose their effectiveness quickly.

An additional risk of water hammer occurs in the filling and pressurization of anempty system either the initial fill of a new system, or refilling a system that has beendrained. This situation is more likely to present problems in large diameter, extensivesystems. The best protection is to slowly fill the system and slowly vent air from high

points and from only one point at a time if there is more than one point that develops an air trap.


17/147



11

NOTE: Surge pressures are of very short duration, and they cannot bemeasured with standard pressure gauges. System design should provide for line pressure

plus a surge allowance.

J OINING PLASTIC PIPE CUTTING PLASTIC PIPE AND TUBINGPlastic pipe and tubing can be easily cut with a wide variety of saws, knives, shears

and cutting wheels. Refer to the specific lesson for the recommended type of cutter to usewith a specific material.

SOLVENT CEMENT JOINING

ABS, CPVC, and PVC plastic pipes are primarily joined by solvent cementing butmechanical joints are also available. PB, PE, PEX, and PP pipe cannot be joined withsolvent cements.

Solvent cement joining always involves a pipe or tube end and fitting socket or pipe bell. The inside of the socket is slightly tapered, from a diameter slightly larger than

the pipe OD at the entry, to a dimension at the root of the socket that is a few thousandthsof an inch smaller than the pipe OD. Thus, the pipe-to-socket match-up results in aninterference fit more-or-less midway in the socket.

Solvent cement is applied to the outside of the pipe end and the inside of the socket.The pipe is then pushed into the socket until it bottoms. Some codes require a primer to beapplied before the solvent cement.

Pipe and fittings are bonded together by means of chemical fusion. Solventscontained in primer and cement soften and dissolve the surfaces to be joined. Once the

pipe and fitting are assembled, a chemical weld occurs. This weld strengthens over time asthe solvents evaporate.

See ASTM F 402 for safe handling of solvent cements, ASTM D 2855 for PVC

instructions, ASTM F 493 for CPVC instructions, ASTM D 2235 for ABS instructions, or the cement manufacturers instructions printed on the container label for further information.

SAFE HANDLING PROCEDURESThese cements, primers, and cleaners contain solvents that are classified as

combustible, flammable, or extremely flammable. Keep these products well away from allsources of ignition, such as sparks, heat, and open flames. Containers holding these

products must be kept tightly closed, except when in use.Threshold limits for worker exposure during an eight-hour workday have been

established for each of the solvents used in these products. Those limits are found on the

Material Safety Data Sheets of each product. It is very important to maintain the air concentration of these solvents below these limits. When using these products in an areaof limited ventilation, a ventilating device such as a fan or air mover can be used tomaintain a safe air concentration. Also, an air-purifying NIOSH-recognized respirator may

be used. Any ventilating device must be selected and located so it cannot provide a sourceof ignition.


18/147



12

The solvents in these products should not come into contact with bare skin. Use of the applicators provided to apply the products can minimize skin contact. However, if skincontact cannot be avoided, protective gloves should be worn.

The solvents in these products will cause severe irritation if they come into contactwith the eyes. Proper eye protection must be worn whenever there is any possibility that

such contact may occur.These cements must not be ingested. Do not eat or drink when using cements, primers, or cleaners.

ELASTOMERIC SEALING GASKETMost underground PVC pressure and sewer piping is joined by means of an

elastomeric O - ring or seal that is held within a hub, with the pipe inserted into the ring.The pipe is cut to the desired length; the end is smoothed inside and out. A lubricant isapplied to the pipe end, and the pipe is inserted into the hub and gasket with a quick push.

Note that two different ASTM standards apply to elastomeric seal gravity jointsand pressure joints (D 3212 and D 3139, respectively).

MECHANICAL FITTING JOINING

PB, PE, and PEX tubing are often joined by mechanical means to fittingsdeveloped for that purpose. Several general versions are available each uses a metalinsert stiffener inside the tube. Always check on the product label or in the manufacturersliterature or instructions to make sure that the mechanical fitting joining system isrecommended for the type of service on which the fittings will be used (for example,

potable water, hydronic heating, gas service, etc.).

1. Crimp Ring TypeA crimp ring surrounding the tube and insert is compressed by a special

crimp tool after assembly. The crimp ring version is a one-time assembly,i.e., it must be destroyed to disassemble this joint.

2. Nut Ferrule TypeA threaded nut is tightened onto a matching thread and compresses the tubeor a ferrule over the insert as it is made up tight. The threaded nut versioncan be taken apart and reassembled as necessary.

3. Stab TypeThe plastic pipe or tubing is cut, the end is chamfered, the stab depth ismarked on the pipe or tubing, and then it is stabbed into the fitting.

FLANGESCPVC and PVC piping can be joined by bolting together flanges that are attached

to the pipe end (usually by solvent-cement joint). A thin, flat gasket is placed between theflange faces to make a leak-tight joint. Care must be taken to bolt the flanges together inthe manner recommended by the manufacturer to develop a tight joint and avoid damagingthe flanges.


19/147



13

HEAT FUSION JOINING

There are four types of heat fusion joints:

1. Butt fusion2. Socket fusion

3. Electrofusion4. Saddle fusion

Butt heat fusion joining is accomplished by heating the two ends of pipe or tubingto be joined to the required temperature in special heating devices and then quickly

pushing the ends together with a controlled force. Special tools are used to obtain therequired temperature and to control the mating force. This method is used on PB, PE, PPand PVDF pipe and produces a quality joint in these materials.

The socket fusion and saddle fusion processes are similar to butt fusion except thatdifferent heating tools are required. In the electrofusion process, the required temperatureand heating time are controlled by passing current through an electrical resistance wire

embedded in the socket. THREADED JOINTSSome plastic pipe fittings are available that consist of NPT thread on one end and

plastic male (spigot) or female (socket) on the other. These fittings are used as adapters to join one piping material to another.

Schedule 80 CPVC and PVC plastic pipe can be threaded if special dies are used.Pipe threads shall conform to ASTM F 1498. Threading pipe reduces its working pressure

by 50 percent. The rated working pressure of systems assembled with threaded joints will be less than the working pressure with solvent cement joints. An advantage of this methodis that disassembly is easily accomplished when necessary.

PTFE (i.e., DuPont Teflon) tape is compatible and recommended for use with all plastic piping materials. Some paste type sealants contain ingredients that can damagecertain plastic piping system components. Use only paste thread sealants recommendedfor the plastic piping system used.


20/147



14


21/147



a VARIETY OF JOINING METHODS

Plastic piping can be joined by numerous methods. For each material there areseveral appropriate methods. Some of the most common are solvent cementing, heatfusion, threaded joints, flanges, O-rings, rolled grooves, and mechanical compression

joints. This variety of joining methods allows plastic piping to be adapted easily to most

field conditions.a NONTOXIC

Plastic piping systems have been approved for potable water applications. Asevidence of this all plastic potable water piping materials and products are tested and listedfor compliance to ANSI/NSF Standards 14 and 61.

All ASTM and AWWA standards for plastic pressure piping that could be used for potable water contain a provision whereby the regulatory authority or user can require product that has been tested and found to be in conformance with ANSI/NSF Standard 61 Drinking Water System Components Health Effects. When plastic pipe or fittingsare ANSI/NSF Standard 14 listed, and have the NSF pw (potable water) mark they also

meet the ANSI/NSF Standard 61 requirements.To assure installers, regulators, and users of plastic piping that these products areacceptable for potable water applications, the plastic piping industry has dealt with theissue as follows:

All plastic piping material manufacturers have recognized the need to provide materials for all pressure pipes and all pressure pipe fittings thatmeet the requirements of ANSI/NSF Standard 61.

All manufacturers of these pipes and fittings have pressure pipe and fittingslisted as meeting the requirements of ANSI/NSF Standard 61. These

products can be identified by the NSF-pw, NSF-61, UL Classified/Std 61mark or a similar pw mark (by another recognized listing agency) printed onthe pipe or molded into the fitting.

NOTE: The NSF-pw mark certifies to installers, users, andregulators that the product meets the requirements of ANSI/NSF Std 14for performance and the ANSI/NSF STD 61 for health effects. Productsmarked with Std 61 have only been evaluated as meeting the requirementsof NSF 61 for health effects.


22/147



a BIOLOGICAL RESISTANCETo date, there are no documented reports on any fungi, bacteria, or termite attacks

on any plastic piping system. In fact, because of its inertness, plastic piping is the preferred material in deionized and other high-purity water applications.

a ABRASION RESISTANCEPlastic piping materials provide excellent service in handling slurries such as fly

ash, bottom ash, and other abrasive solutions. The material toughness and the smoothinner-bore of plastic piping make it ideal for applications where abrasion-resistance isneeded.

a COLORED PIPING

Plastic piping is available in a variety of colors. Do not, however, depend on the pipe color as a factor in determining proper application. The following are generally usedcolors for different applications:

Gas Distribution formerly bright orange or tan; now yellow or black with yellow stripes

Water Distribution Black, light blue, white, clear, or gray

Sewers Green, white, black, or gray

DWV Black, white, tan, or gray

Hot and Cold Water

Distribution Tan, red, white, blue, silver, or clear Cable Duct Variety of colors

Fire Sprinklers Orange

Industrial Process Dark gray/PVC, light gray/CPVC

Reclaimed Water Purple or brown (local jurisdiction may setrequirements)

Do not rely on color to identify the piping application.Read the printing on the pipe.


23/147



a MAINTENANCE

A properly designed and installed plastic piping system requires very littlemaintenance because there is no rust, pitting, or scaling to contend with. The interior andexterior piping surfaces are not subject to galvanic corrosion or electrolysis. In buriedapplications, the plastic piping is not generally affected by chemically aggressive soil.

However, installation in soils contaminated with hydrocarbons (gas, oil, etc.) should beavoided.


24/147




25/147



15

LLee ss ss oo nn 33::PP r r oo pp ee r r ttiiee ss oo f f PP llaa ss ttiicc PP iipp iinn gg

This lesson continues the description of plastic piping material characteristics to aidin determining which plastic material is best for a given application.

P HYSICAL CHARACTERISTICS

a RIGID (STRAIGHT PIPE ) MATERIALSABS, CPVC, PVC and PP materials are stiffer than the other plastic piping

materials. This property means that these pipes retain their shape and are usually sold instraight, rigid lengths. They main tain their r ound cross-section . It is possible to usesolvent cement joints with socket fittings or elastomeric rings held in hubs that seal againstthe OD of the pipe.

These pipes, when installed in a horizontal position, can be supported with hangersat spacings of up to a few feet (more on this subject later).

The straight, rigid lengths also assure a uniform slope for gravity drain lines so thatsags and traps are not formed in the line sags and traps that can permit stoppages toform.

a NON -RIGID (FLEXIBLE PIPE ) MATERIALSPB, PE, and PEX piping materials, unlike those described above (ABS, CPVC, and

PVC) are more flexible so they are available in coils of various lengths (up to 1000 feet insome cases). The piping can be bent, thus minimizing fittings and joints, but it must besupported continuously or on close centers. The flexible tubing can be used for very smalldrains, serving clear water, such as condensate from cooling coils.

These materials cannot be solvent-cemented. PB and PE must be joined by heatfusion or with mechanical joints that seal against the pipe wall with external compressiveforce developed by draw bands, crimp rings, o-rings, or compression nuts. In NorthAmerica, PEX can only be joined with mechanical fittings; it cannot be heat fused.

NOTE: There are always exceptions. In small sizes PVC and CPVC pipe and tube can be coiled.


26/147



16

P IPING STANDARDS DIMENSIONS AND TERMINOLOGYPlastic pipe and fittings are manufactured to conform to various widely recognized

standard sets of dimensions.There are several OD controlled dimensioning systems (e.g. IPS, Sewer and CTS),

and each can have one or more wall thickness designations. They correlate, in general,with product applications and material. Most of the ASTM Standards for pressure pipe are

based on the IPS (Iron Pipe Size) OD system or the CTS (Copper Tube Size) tube products. These pipes and tubes are made with both schedule and SDR wallthicknesses. Most of the sewer pipes are based on sewer pipe size ODs that are smaller than the IPS ODs; they use DR or pipe stiffness wall designations.

The CTS OD system utilizes the same outside diameters that are used for copper water tube. Most of these utilize the SDR wall thicknesses.

M ETRICSThe federal government has determined that the United States must convert to the

metric system, and they are spending large sums each year on construction that is beingdesigned using metric units and being built with metric products, if they are available fromUnited States suppliers. Thus far, all plastic and metal piping being produced in the UnitedStates for domestic use is made to inch-pound units, even though all the ASTM standardsfor plastic pipe contain metric equivalents.

Until the metal pipe industry goes to hard metric standards, the plastic pipeindustry has no choice but to stay with the inch-dimensioned products. A completediscussion of the ISO standards writing process and the ISO metric standards for plastic

piping will be covered in an advanced course.

IPS SCHEDULES 40, 80, AND 120When standards for steel pipe were developed many years ago, certain wall

thicknesses were given Schedule numbers, e.g. 40, 80 and 120. For a given nominal pipesize, the outside diameter (OD) of a pipe is the same for any schedule. Thus, this is anoutside diameter controlled system. The most common dimensions in this system are

based on Sch 40, which is a moderately heavy wall material. For a still heavier wall, thedimension standard most often used is Sch 80. Schedule 120 (heavier still) is available insome plastic pipe materials.

When a single material is made into pipe of a given Schedule number (e.g. Sch 40),the rated working pressure of the pipe is affected by pipe diameter. The larger the pipe, thelower the pressure rating for the same Schedule number.

Note that a larger Schedule number means a heavier wal l . At one time, the Sch 40

steel pipe was called standard weight, and the Sch 80 steel pipe was called extraheavy.

Table 3-A shows dimensions for several sizes of pipe. Table 3-B shows pressureratings for Schedule 40 and 80 pipe made from ABS, PE and PVC.


27/147



17

Table 3-A: Plastic Pipe Dimensional Data(Based on IPS Pipe Standard by AISI)

Size Nominal(in)

Nominal OD(in)

Min. Wall Thickness (in)

Sch 40* Sch 80** Sch 1200.405 0.068 0.095 -

0.540 0.088 0.119 -

0.675 0.91 0.126 -

0.840 0.109 0.147 0.170

1.050 0.113 0.154 0.170

1 1.315 0.133 0.179 0.200

1 1.660 0.140 0.191 0.215

1 1.900 0.145 0.200 0.2252 2.375 0.154 0.218 0.250

2 2.875 0.203 0.276 0.300

3 3.500 0.216 0.300 0.350

3 4.000 0.226 0.318 0.350

4 4.500 0.237 0.337 0.437

5 5.563 0.258 0.375 0.500

6 6.625 0.280 0.432 0.562

8 8.625 0.322 0.500 0.718

10 10.750 0.365 0.593 0.843

12 12.750 0.406 0.687 1.000

*Originally called standard weight steel pipe**Originally called extra heavy steel pipe.


28/147



18

Table 3-B: Plastic Pipe Pressure Ratings @ 73 F (psi)Pipe Size (in) ABS 1316 (D 1527) PVC 1120 (D 1785) PE 3408 (D 2447)

Sch 40 Sch 80 Sch 40 Sch 80 Sch 40 Sch 80

480 680 600 850 240 340

390 550 480 690 195 275

1 360 500 450 630 180 250

1 290 420 370 520 145 210

1 260 380 330 470 130 190

2 220 320 280 400 110 160

2 240 340 300 420 120 170

3 210 300 260 370 105 150

3 190 280 240 350 95 140

4 180 260 220 320 90 130

5 160 230 190 290 80 115

6 140 220 180 280 70 110

8 120 200 160 250 60 100

10 110 190 140 230 55 95

12 110 180 130 230 55 90

Note that the above values are for unthreaded pipe. Threading pipe reduces pressure ratings and may not be allowed for some materials. See the individual materiallessons for more information.


29/147



19

DR , SDR , AND SIDR GeneralThe DR (Di mension Ratio) system produces a series of pipe for which the pressure

rating is the same for all pipe sizes when they are made of the same plastic material. For

any given DR, the wall thickness equals the pipe outside diameter divided by the DR for each pipe size. In the SDR (Standard Dimension Ratio) system, a series of preferrednumbers was selected in which each number is 25 percent greater than the previous one.Therefore, in the SDR pipes the pressure ratings also increase by 25 percent increments.There are ASTM standards for all major plastic piping products based on the DR and SDR concept.

The Inside Diameter (ID) controlled pipes used with insert fittings also use the DR system by dividing ID by the DR to establish wall thickness. All standards for IDcontrolled plastic pressure pipe have the term SIDR (Standard I nside Di ameter Ratio) inthe title.

Pressure PipingMost of the plastic pressure piping is OD (outside diameter) controlled so that thefittings can be used with pipes having varying pressure ratings. The majority of the plastic

piping standards are based on the SDR or DR system, but sometimes the terms (DR andSDR) are interchanged. For examples of SDR ASTM standards see D 2241 (PVC), D2282 (ABS), D 3035 (PE), and F 441 (CPVC). In these standards you will see that SDRs7, 9, 11, 13.5, 17, 21, 26 and 32.6 are used. Although much of the plastic pressure pipingis based on IPS ODs, there are some ASTM standards based on CTS (copper tube size)ODs and some AWWA plastic pipe standards based on Cast Iron pressure pipe ODs.Table 3-C shows some SDR PE pipe values taken from ASTM D 3035.

While there are only a few ASTM Standards for ID (Inside Diameter) controlled

plastic piping (see PB, PE, and PEX lessons), they must be recognized in order to avoid joining problems. The SIDR concept is explained above, and details of dimensionaldifferences are given in the ASTM standards. Table 3-C also shows some SIDR PE pipevalues taken from ASTM D 2239, and it shows how the SDR and SIDR numbers arerelated.

In Table 3-C, the SDR and SIDR pipes shown on the same line have the same pressure rating (e.g., SDR 9 and SIDR 7) when the same PE material is used. Here youcan see how the pipe ODs change for the SIDR pipes and the IDs change for the SDR pipe.

Note that a smaller SDR (or SIDR) number means a heavier wal l .

Non-Pressure PipingSome of the non-pressure piping standards show OD controlled pipes (e.g. IPS Sch

40 for PVC and ABS DWV, Schedule 40 and Schedule 80 PE and PP per ASTM F 1412)and some have Sewer Pipe sizing (see D 2729, D 2751, and D 3034). The latter use bothSDR and DR systems in their dimensioning. A review of the IPS and Sewer pipestandards show these OD differences:

4 inch IPS OD = 4.500 inches4 inch sewer pipe OD = 4.215 inches


30/147



20

These OD differences continue over the whole range of pipe sizes. However, there arealso several standards for ID controlled non-pressure pipes. These include Corrugated PEand PVC pipe, profile wall PE and PVC pipe, cellular core PE and PVC pipe and evenPVC/ABS truss pipe.

Table 3-C: Minimum Wall Thickness Of 2-inch Pipe Based on SDR/SIDR

IPS-OD SDR OUTSIDE DIAMETER = 2.375 in

IPS-ID SIDR INSIDE DIAMETER = 2.067 in

SDR (D 3035) WALL SIDR (D 2239) WALL

7 0.339 5.3 0.390

9 0.264 7 0.295

11 0.216 9 0.230

13.5 0.176 11.5 0.18017 0.140 15 0.138

21 0.113 19 0.109

26 0.091 24 0.089

32.5 0.073 30.5 0.071

See also the Appendix at the end of this lesson for a general discussion of SDRs andSIDRs.

T EMPERATURE EFFECTS MATERIALS WITH 73 F HDS RATINGABS, PE and PVC materials are all available with 73 F stress rating for use in

pressure piping. PE piping is used extensively for cold water service lines and water distribution systems outside the building. Its low temperature flexibility makes itespecially suited for use in applications where temperature of 35 F and lower will occur.

ABS and PVC piping have been used for many years in residential DWV systemswhere intermittent temperature excursions up to 180 F can occur. The maximumtemperature at which PE has an HDS rating is 140 F.

MATERIALS WITH HDS RATINGS FOR HIGHER TEMPERATURESChlorinated Poly (Vinyl Chloride) (CPVC), Polybutylene (PB), and cross-linked

polyethylene (PEX) materials are available that are rated for long term service at 180 F aswell as for cold water applications. Hot and cold water distribution system piping madefrom these materials has a working pressure rating of 100 psi at 180 F. These systems aretested at 150 psi at 210 F for at least 48 hours to assure integrity at those conditions,which may develop in the event the water heater controls malfunction. Thus, such


31/147



21

materials are suitable for hot water distribution where water heaters are installed with relief valves set at 150 psi, 210 F.

All plumbing codes require the use of piping having the 100 psi at 180 F rating for both the hot and the cold water portions of the water distribution system.

EXPANSION /CONTRACTIONWhile the coefficients of expansion for various plastic materials are not identical, ingeneral plastic materials have about eight times the expansion of steel, or four times theexpansion coefficient for copper. While these facts must be recognized, proper allowancefor the expansion characteristics can be readily accomplished.

To prevent expansion/contraction from adversely affecting a piping installation, thefollowing techniques can be used:

1. Underground piping with solvent cement joints or flexible pipe should besnaked in a ditch.

2. For underground pressure and non-pressure lines, gasket in bell joints can

be used when they are available and suitable for the specific pipe materialand the piping system.3. For long straight lines in buildings, use offsets or changes in direction.4. When none of the above suffice, use expansion joints per the pipe

manufacturers recommendations, and hangers that permit movement.

C HEMICAL RESISTANCEMost plastic materials are derived from petroleum-based materials. As a result,

they are generally not suitable for piping for petroleum liquids, or for liquids where evensmall amounts of petroleum liquids are present. The main example of this last sort is acompressed air system where liquids may be present derived from oil-lubricated

compressors. The vast majority of compressed air systems are of this type. Thecompressor lubricants, in very small amounts, gradually accumulate in the piping downstream of the compressor. Thus the compressed air piping becomes oil-coated on theinside surface after a very short time which can cause premature failure of the plastic pipe.

An additional serious reason to avoid plastic pipe on compressed gas systems isdiscussed in the section that follows: PRESSURIZED GASES .

NOTE: There is an exception to the petroleum use issue. For many years,PE and PVC piping has been the material of choice to convey oilwell brine because it provides the best combination of rigidity,chemical resistance and durability at the lowest cost.

Plastic materials are capable of containing many of the chemicals encountered inindustry. For more details about resistance to specific reagents, mixtures, temperature, and

pressure-use conditions, consult the pipe manufacturer.


32/147



22

POTABLE WATER PIPING

The following note is included in many of the ASTM standards that describe plastic pressure piping that may be used to convey potable water:

Potable Water Requirement: Products intended for contact with

potable water shall be evaluated, tested, and certified for conformancewith a ANSI/NSF Standard No. 61 or the health effects portion of NSFStandard No. 14 by an acceptable certifying organization whenrequired by the regulatory authority having jurisdiction.

Aggressive soft and hard potable waters have no effect on plastic pipe materials.

PLASTIC DWV AND SEWER PIPING

Plastic pipe is not affected by sanitary waste, drain cleaners, or drain cleaning tools.Plastic pipe is not affected by external corrosive environments that can destroy metal pipe.Similarly, these considerations also apply to septic tank outlet lines. However, it has been

found that creosote or some treatments that use petroleum-based carriers may affect plastic pipe.

PROCESS PIPINGPlastic pipe systems have given excellent service in water treatment plants, sewage

treatment plants, and numerous industrial processes. Be aware that reagent concentration,stress level, operating temperature, and expected service life can all be factors inevaluating the plastic piping material. The most effective evaluation is often done under actual service conditions, but this must always be done with care for safety.

P RESSURIZED GASES

ABS, PVC, and CPVC pipe and fitting products shall not be used in pipingsystems intended to store and/or convey compressed air or other gases. Furthermore, these piping systems shall not be tested with compressed air or other gases unless the procedure being used has been clearly and specifically approved by the manufacturer(s) of the plastic products or system to be tested.

NOTE: By virtue of their compressibility, compressed air and gases containlarge amounts of stored energy which present serious safety hazards should a pipingsystem fail for any reason.

COMPRESSED AIR PIPING SYSTEMS

Some manufacturers offer a piping material for compressed air applications. If struck with sufficient force, a hole may be formed, or the pipe may be broken, but it doesnot shatter. See the manufacturers literature for complete details of pressure rating limitsand use conditions.

The plumbing codes permit the use of buried polyethylene (PE) fuel gas piping for the distribution of natural gas, LP gas vapor, and other fuel gases. The same codes requirethat these piping systems be manufactured and marked ASTM D 2513 and berecommended by the manufacturer for fuel gas service. All such PE fuel gas piping must


33/147



23

be installed underground except that PE gas piping may terminate above ground, andoutside of buildings, when encased inside an anodeless riser designed and recommendedfor such uses. Check with the codes of the authority having jurisdiction for any specialrequirements for such installations.


34/147



24

APPENDIX TO LESSON THREE

STANDARD DIMENSION RATIO (SDR) AND STANDARD INSIDE DIMENSION RATIO (SIDR)

SDR A specific ratio of the average specified outside diameter to the minimumspecified wall thickness (D o/t) for outside diameter-controlled plastic pipe, the value of which is derived by adding 1 to the pertinent number selected from the ANSI PreferredNumber Series 10.The SIDR (D i /t) is derived by subtracting 1 from the ANSI Preferred Number Series 10.

ANSI Preferred Number Series 10 SDR SIDR

5.0 6.3 8.010.012.516.020.025.031.540.050.063.0

6.0 7.3 9.011.013.517.021.026.032.541.051.064.0

4.0 5.3 7.0 9.011.515.019.024.030.539.049.062.0

See reference: ANSI Preferred Numbers. Z17.1 (Designated as R 10 in ISO 3 and ISO 497.)


35/147


Lesson 4. 2002 PPFA.Click here to return to Table of Contents. 25

LLee ss ss oo nn 44::DDee ttaa iillee dd DDiiss cc uu ss ss iioo nn OO f f AAcc r r yy lloo nn iittr r iillee --BBuu ttaa dd iiee nn ee --SS ttyyr r ee nn ee

((AABB SS ))PP llaa ss ttiicc PP iipp iinn ggG ENERAL

Acrylonitrile-butadiene-styrene (ABS) plastic materials are manufactured byextrusion in sizes and to the ASTM Standards shown in Table 4-A. Most ABSapplications are for DWV uses, but ABS pressure pipe is available for certain industrialapplications. The pipe is sold in 10 foot and 20 foot lengths, and 12 foot lengths in Canada.

ABS pipe and fittings for DWV use are made from ABS compounds meeting therequirements of ASTM D 3965 Cell Classification 4-2-2-2-2 for pipe, and 3-2-2-2-2 for fittings.

ABS pipe is available in solid core and cellular (foam) core construction inSchedule 40 dimensions. These two forms may be used interchangeably for DWVapplications. Cellular core construction involvesthe simultaneous extrusion of three layers into the

pipe wall a solid outer layer, a foam intermediatelayer, and a solid inner layer. The inner surface

provides the smooth, continuous surface necessaryfor satisfactory flow characteristics, and the outer segment develops the beam strength necessary for the product to behave like a pipe. The closed-cellcore holds the outer and inner layers in positionwith each other, but requires less material to do socompared to a solid layer. The result is a lighter, more cost-effective pipe that iscompletely satisfactory for DWV applications. See Figure 4-A.

ULTRAVIOLET RADIATION Nearly all plastics can be affected by ultraviolet (UV) radiation (such as found in

sunlight). ABS is affected by long-term exposure to ultraviolet radiation (UV) and carbon black is added to help shield the ABS pipe grades from such radiation. Short-termexposure such as during construction is not a problem; however, avoid long term extendedoutdoor exposure. Store materials under cover to minimize long-term exposure to directsunlight.

Figure 4-A: Cellular Core PipeTypical Cross-Section (Not to Scale)


36/147


26 Lesson 4. 2002 PPFA.Click here to return to Table of Contents.

USESSch 40 ABS piping, both solid wall and cellular core, is accepted for DWV systems

in all plumbing codes. ABS solid wall pipe is made in Sch 40, Sch 80, and StandardDimension Ratio (SDR) wall thickness for potable cold water distribution uses, but thisapplication is not in common use today. Table 4-A provides information about these

products, including the ASTM standards that apply.

Table 4-A: ABS Pipe StandardsABS ASTM SIZES

(IN)TEMPERATURE

RANGE FPRESSURERATED at73 F (psi)

DIMENSIONSTANDARD

ABS DWV, solid core, pipe and fi ttings

D 2661 1-6 Up to 180 NA Sch 40

ABS, DWV, cellular core, pipe

F 628 1 - 6 Up to 180 NA Sch 40

ABS plastic pipe(SDR-PR)

D 2282* 1 -12 73 80-250 SDR 13.5, 17, 21,26

ABS plastic pipefittings, Sch 40 D 2468* 1 -8 73

NA Sch 40

ABS plastic pipe Sch40 & 80

D 1527* 1 -12 73 50-500 Sch 40, 80

ABS sewer pipe &fittings

D 2751 3-12 Up to 180 NA DR 23.5, 35, 42

Solvent cement for ABS plastic pipe andfittings

D 2235 MatchesPipe/Fittings or asrecommended by

cement manufacturer

NA NA

Standard Practice for Safe Handling of Solvent Cements,Primers and CleanersUsed for JoiningThermoplastic Pipeand Fittings

F 402 NA NA NA NA

Only available as special order product.

While ABS materials are resistant to many ordinary chemicals, only themanufacturer of the pipe can recommend suitable uses for special waste systems or industrial process system. In general, ABS materials are able to contain weak inorganicreagents. Applications that involve petroleum-based products should be avoided. SeeLesson 15 for more information on various chemicals and suitable plastic pipe materials.

COMPRESSED GAS USE TO BE AVOIDED

ABS pipe and fitting products shall not be used in piping systems intended to storeand/or convey compressed air or other gases. Furthermore, these piping systems shall not

be tested with compressed air or other gases unless the procedure being used has beenclearly and specifically approved by the manufacturer(s) of the plastic products or systemto be tested.


37/147


Lesson 4. 2002 PPFA 27Click here to return to Table of Contents .

NOTE: By virtue of their compressibility, compressed air and gases containlarge amounts of stored energy which present serious safety hazardsshould a piping system fail for any reason.

C ODE STATUS

ABS pipe and fittings are recognized as acceptable for use in DWV systems in allmajor model plumbing codes.

AVAILABILITYABS pipe and fittings are available from plumbing supply houses throughout the

North America.

INSTALLED LOCATIONSABS pipe and fittings may be used both above and below ground. Outdoor

applications are permitted provided the pipe is further protected from UV light exposure bya water-borne chemically compatible latex paint. Check with the ABS pipe supplier for further information.

INSTALLATION METHODSIn all cases, careful workmanship and attention to detail are required for a

successful long-term installation. Appropriate local code requirements must be followed.

HORIZONTAL ABOVE GROUND

Support horizontal piping above ground according to Table 4-B or as required,using hangers that are wide enough to avoid deforming the pipe at the point of support.Typical clevis hangers ranging from about -inches wide in the smallest sizes to more than1-inch in the largest are usually suitable. If the contents to be carried will be hot (over 120 F), wider saddles would be advisable to reduce the risk of long-term creep. Alsoconsult the local authority having jurisdiction.

Table 4-B: ABS Pipe Support SpacingSIZE (in) MAXIMUM SPACING (ft)

1 - 2 3

3 - 4 4

6 - 8 5

10 - 12 6


38/147



FRAME CONSTRUCTIONABS pipe may be installed in wall or ceiling framing. The pipe should be protected

from nail or screw penetrations by using nail plates wherever the pipe passes throughframing members.

UNDER SLABPipe installed under slab is not harmed by direct contact with concrete. When

performing under-slab installations, it is important that the pipe be continuously supportedalong its entire length. Backfill should be free of sharp rocks and other debris that coulddamage the pipe. Gravel is an acceptable bedding material.

TRENCHES

Piping installed in trenches in the ground must be placed in continuous bearing and backfilled with sand or granular earth, carefully tamped on each side and to 6 inches abovethe pipe. After the pipe is so bedded, the rest of the trench can be backfilled to the surface.

VERTICAL

Vertical piping should be supported at every floor or every ten feet, whichever isless. Check also for local code requirements that may be more stringent.

TESTINGABS piping installations shall not be tested with compressed gas. Hydrostatic

testing is safe and is the recommended method.

E XPANSION /CONTRACTIONPlastic materials generally have a much larger coefficient of expansion than metals.

This fact, however, does not automatically mean that expansion problems are a significantconcern for every plastic pipe installation. There are several reasons why the greater coefficient is seldom a problem, including the following:

1. The great majority of plastic installations involve relatively short pipesegments, where the absolute value of dimension change (with even largetemperature change) is not great. In addition, especially for DWV,conditions are usually found that the complete run of piping is not warmedat the same time. That is, a volume of hot water enters the pipe and travelsto the discharge end, warming the pipe in a moving wave. There is alsousually significant cooling of the water as the wave moves down the pipe.

2. Most installations operate in an environment that has very little temperaturechange piping in earth or in air conditioned buildings being two major examples.

3. Piping carrying cold water will also see very little temperature change.

For those cases where significant temperature change is a factor, pipingdimensional change is accommodated at changes in direction, by piping offsets, bysnaking the line (as in a long trench), or by use of expansion joints.


39/147



J OINING METHODS

SOCKET WITH SOLVENT CEMENTThe most commonly used joining method for ABS pipe and fittings uses a solvent-

cement on the pipe end and in the inside of the fitting socket. The pipe end and socketmust be free of dirt, loose particles, or moisture. The ABS pipe and fitting are assembledafter placing solvent cement on the outside of the pipe and the inside of the fitting cupimmediately before inserting the pipe into the fitting socket.

The inside of the socket is made with a slight taper, with the diameter greater thanthe pipe OD at the open end of the socket to less than the OD of the pipe at the bottom of the socket. Thus, there is an interference between the outside diameter of the pipe and theinside of the socket approximately midway into the socket. The solvent -cement permitsthe pipe and fitting material to flow sufficiently to allow the pipe to bottom in the socket,and a solid, substantial joint is formed as soon as the cement sets usually a matter of oneto two minutes (depending on conditions).

The solvent cement manufacturers recommendations should be followed carefullyin all details to produce a serviceable joint. Figures 4-B, 4-C, and 4-D show the joint as itis being assembled and completed. For additional information, see ASTM F 402, StandardPractices for Safe Handling of Solvent Cements, Primers, and Cleaners Used for JoiningThermoplastic Pipe and Fittings.

The cement used to join plastic pipe and fittings consists of a solvent appropriate tothe plastic being joined, and some of the same plastic type dissolved in the mix. Thus,there is no universal, or multi-purpose, plastic solvent cement possible. Each plastic

piping material must use the correct solvent-cement for that type material.Although some multi-purpose solvent cements are available, most pipe and fitting

manufacturers do not recommend their use. Likewise, model plumbing codes do not

permit such use.

Figure 4-B: Cement coatings of sufficient thickness. Joint surfaces must be assembledwhile surfaces are wet and soft. Courtesy NIBCO, Inc.


40/147



ELASTOMERIC SLEEVE COUPLING DWVWhile the solvent-cement method is the most widely used technique for joining

ABS, couplings consisting of an elastomeric sleeve and draw bands also provide asatisfactory joint. These couplings are used to join two plain pipe ends. The couplingmost often used is made to conform to CISPI-310-90, and others are available. The user should check local codes for a list of acceptable couplings. Figure 4-E shows a typicalassembly.

Figure 4-C: Solvent cement joint beingassembled. Surfaces must be assembled whilethey are wet and soft. Courtesy NIBCO, Inc.

Figure 4-D: Completed solvent cement joint. Note bonded and fused surfaces. Courtesy NIBCO, Inc.


41/147



Figure 4-E: Elastomeric Gasket Joint, DWV

ELASTOMERIC GASKET BELLED PIPESome ABS sewer pipe is joined with a hub and spigot assembly that uses an

elastomeric gasket to form the seal. The hub, or belled, end of the pipe is formed when the pipe is manufactured, and it contains an elastomeric seal which seats against the pipe wallwhen the plain pipe end is pushed into the bell. The pipe end must be chamfered andlubricated to facilitate joint assembly. Figure 4-F shows a typical joint.

Figure 4-F: Elastomeric gasket joint hub and spigot


42/147



SOCKET FITTING WELDING

ABS pipe-to-socket joints can be made by fillet welding the top of the socket to thewall of the pipe. The region to be welded is heated to about 500 F to form a puddle and a

stick of ABS (about1

/8-inch square) is worked into the puddle. The puddle is worked allaround the joint to form a complete weld. Multiple passes are required. The heat source isa stream of nitrogen or compressed air that is heated in a special electric gun.

TRANSITION JOINTS

Suitable techniques and products are available to join ABS to any other pipingmaterial. The main methods are the following.

El astomer ic coupl in gs with compression clamps are used to join two plain pipeends together. These couplings are available for cast-iron soil pipe to plastic pipe, and for copper tube to plastic pipe. For steel pipe to plastic (both made to Sch 40 dimensions), thestandard CISPI coupling described above is satisfactory. Plastic adapter fittings are also

made that provide a contour with a raised ridge to provide a better gripping area for theelastomeric coupling. Figure 4-G shows a typical joint.

Figure 4-G: Elastomeric coupling with coupling clamp


43/147



Th readed adapters are used to join a pipe thread to ABS pipe. The ABS portionmay be either spigot (pipe OD size) or socket, and the threaded portion may be either maleor female NPT threads. An essential requirement for the thread joint is that the thread sealcan only be Teflon tape or a plastic pipe thread sealant paste specifically tested and

approved for ABS by the manufacturer. Any other thread seal material may containsolvents which can attack the plastic and produce failure of the pipe or joint. Figure 4-Hshows a threaded joint.

Figure 4-H: Threaded adapter

Soil pipe hub adapters are used to join ABS DWV pipe to cast-iron soil pipe at ahub. One end of the ABS fitting consists of a socket to join to the ABS piping, and theother end is a ferrule which has an enlarged end. The ferrule is placed in the hub, which isthen packed with oakum in the usual manner. Lead wool ( not mol ten lead ) is then packedin the remaining space to complete the joint.

FIXTURE CONNECTIONS

ABS piping is connected to the drainage side of plumbing fixtures by variousspecial fittings. Water closets are connected to a closet flange. This fitting consists of either a spigot or socket connection to the ABS drainage piping and a flange that sets atthe floor level to connect to the water closet by bolts. A hand-formed circle of putty or awax ring between the flange face and the water closet base provides a durable water-tightseal.

Lavatory and sink traps are connected to the ABS piping by trap adapters. Theseadapters are available in a variety of configurations and sizes. The piping side may be aspigot or socket solvent cement joint connection. The trap connection side usually has

some form of compression nut and gland to provide the seal to the trap tubing material.


44/147



M ARKINGThe standards for plastic pipe generally require that the product be marked so that it

can be readily identified, even if cut in short pieces. Most of the standards require at leastthe following items:

1. The manufacturers name or trademark 2. The standard to which it conforms3. Pipe size4. Resin type5. DWV if for drainage6. SDR number or Schedule number 7. If the pipe is for potable water, a laboratory seal or mark attesting to

suitability for potable water

In addition, the following information is often shown:

Third party certification mark. Not required by the standard, but it may be required by some codes and jurisdictions.The particular ABS standards differ somewhat on the maximum marking interval

distance, some call for 2 feet and others not more than 1.5 meters (5 feet).


45/147



LLee ss ss oo nn 55::DDee ttaa iillee dd DDiiss cc uu ss ss iioo nn oo f f CC hh lloo r r iinn aa ttee dd PP oo llyy ((VViinn yyll CChh lloo r r iidd ee ))

((CC PP VVCC )) PP llaa ss ttiicc PP iipp iinn gg

G ENERAL

Chlorinated Poly (Vinyl Chloride) (CPVC) is a thermoplastic pipe and fittingmaterial made with CPVC compounds meeting the requirements of ASTM Class 23447 asdefined in ASTM Specification D 1784. CPVC applications are for potable water distribution, corrosive fluid handling in industry, and fire suppression systems. See Table5-A.

Industrial CPVC pipe is manufactured by extrusion in sizes from -inch to 12inches diameter to Sch 40, Sch 80, and SDR (Standard Dimension Ratio) dimensions.

CPVC pipe for plumbing systems is manufactured by extrusion in sizes " through2 inch copper tube size (CTS) dimensions. The CTS plumbing products are made tocopper tube outside diameter dimensions, in accordance with ASTM D 2846 specifi-cations, and have an SDR 11 wall thickness. The pressure ratings of the CTS SDR 11systems are 400 psi (pounds per square inch) at 73 F and 100 psi at 180 F. CPVC

plumbing pipe is sold in both straight lengths and (in small diameters) coils.

STORAGE AND HANDLINGPipe and fittings shall be stored in such a manner to prevent physical damage to the

materials, as well as preventing direct exposure to sunlight. CPVC is affected by long term exposure to ultraviolet radiation. Pigments are added to shield the material from suchradiation. Short term exposure, such as during construction, is not a problem; however,long term exposure such as extended outdoor storage, should be avoided. Permanentoutdoor installations are permitted provided the pipe is further protected by water-basedlatex paint.

Pipe lengths and coils should be properly transported to avoid dragging pipe endsand should not be dropped or thrown from trucks or trailers.

USESCPVC piping which is suitable for hot and cold water distribution has a 400-psi

pressure rating at room temperature, and a 100 psi pressure rating at 180 F.CPVC materials are resistant to many everyday household chemicals, but the

manufacturer of the pipe is the only authority to recommend suitable applications. SeeLesson 15 for a detailed listing of chemicals and suitable plastic pipe materials andcompatible chemicals.

Since CPVC materials do not support combustion, they cannot burn without anexternal fuel source. This property makes CPVC pipe an attractive alternative to steel andcopper pipe for fire sprinkler applications. CPVC fire sprinkler piping systems are


46/147



approved for light hazard applications and for use in single and multifamily dwellings.Installation shall be in accordance with the NFPA Section 13, 13D, and 13R.

C OMPRESSED GAS USE CPVC pipe and fitting products shall not be used in piping systems intended to

store and/or convey compressed air or other gases. Furthermore, these piping systemsshall not be tested with compressed air or other gases unless the procedure being used has

been clearly and specifically approved by the manufacturer(s) of the plastic products or system to be tested.

NOTE: By virtue of their compressibility, compressed air and gasescontain large amounts of stored energy which present serioussafety hazards should a piping system fail for any reason.

C ODE STATUS

PLUMBING APPLICATIONSCPVC piping for potable hot and cold water distribution systems is recognized in

all model plumbing codes.

PLENUM INSTALLATIONCPVC plumbing pipe is safe for installation in return air plenums; however, the

installation must be approved by the local jurisdiction. Even though CPVC is considered acombustible material, it will not burn without a significant external flame source. Once theflame source is removed, CPVC will not sustain combustion. Testing indicates that water filled CPVC in diameters 3 inches or less will pass the 25/50 flame smoke developedrequirements for non-metallic material in return air plenums.

CPVC fire sprinkler pipe tested and listed in accordance with UL 1887, Fire Testof Plastic Sprinkler Pipe for Flame and Smoke Characteristics, meets the requirements of

NFPA 90A for installation in return air plenums.

AVAILABILITYCPVC pipe and fittings are produced by many manufacturers, and are available in

Sch 40 and Sch 80 dimensions, as well as CPVC tubing which is suitable for potable hotand cold water distribution. The tubing is based on copper tube sizes (OD) and IPS pipe(OD), with SDR 11 wall thicknesses.

The ASTM standards and other information for these CPVC piping materials areshown in Table 5-A.


47/147



Table 5-A: CPVC Piping StandardsCPVC ASTM SIZE

(IN)TEMPERATURE

RANGE FPRESSURE RATING AT

73 F (psi)DIMENSION

BASISCPVC Hot & Cold Water Distribution System D 2846 -2 To 180 100-400 SDR 11

CPVC Pipe, Sch 40 & 80 F 441 -12 73-180 130-113025-280

Sch 40, 80

CPVC Pipe SDR-PR F 442 -12 73 125-400 SDR 11, 13.5, 17, 21, 26,32.5

CPVC Sch 80 Socket Fittings F 439 -6 73 Consult the fittingsmanufacturer Sch 80

CPVC Sch 40 Socket Fittings F 438 -6 73 Consult the fittingsmanufacturer

Sch 40

CPVC Threaded Fittings for Sch 80 F 437 -6 73 Consult the fittingsmanufacturer

Sch 80

CPVC Solvent Cements F 493 NA 73 NA

Standard Practice for Safe Handling of Solvent Cements,Primers, and Cleaners Used for Joining Thermoplastic Pipeand Fittings

F 402 NA NA NA NA

NOTE: Sch 40 and Sch 80 references apply only to IPS OD piping . SDR references can apply to all of the OD systems, e.g. IPS, CTS, AWWA, CI, and Sewer


48/147

Lesson 5 Plastic P

ApprenticeManual Plastic Piping

Documents

Transcript of ApprenticeManual Plastic Piping