Steam Line Mechanical Distribution

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DESIGN REFERENCE MANUAL

UTILITIES - MECHANICAL DISTRIBUTION

DESIGN GUIDELINES

PREFACE TO SYSTEM DESIGN GUIDELINES:

The following items represent the preferences of FSG-Utilities-Mechanical Distribution for basicmaterials and systems. It is assumed that manufacturers recommendations are followed in allcases, unless specifically directed otherwise. This document is not intended to cover allaspects of good engineering specifications and is not intended to be a substitute for competentengineering design. This is a living document and will be changed as new technology becomesavailable or old technology is brought to our attention. Any advice on changes will be welcomedand evaluated. Please note dates on all pages and contact FSG-Utilities-MechanicalDistribution for verification that you have the most current copy.

I. STEAM DISTRIBUTION SYSTEM

System Description:

1. Steam is distributed throughout the campus via looped high and low pressuredistribution systems. Radial feeds also exist to some locations on campus. Forreliability and maintainability, looped systems are preferred wherever possible.Low pressure use is preferred wherever possible for economic and safetyreasons.

2. The high pressure system is operated at 155 psig, 410 F (40F superheat). Thelow pressure system is operated at 20 psig, 300 F (40F superheat). Thepressures and temperatures indicated above are nominal at the Power Plant.The actual pressures and temperatures fluctuate based on Power Plantoperation and location in the system. NOTE: Because the 20 psig system is

connected to the 155 psig system through pressure reducing valves (PRVs) innumerous places, the same anchoring and expansion standards are used for the20 psig system and the 155 psig system, with any exceptions noted.

3. The Oakdale Campus is served through a 125 psig steam distribution system.The 125 psig system is operated at saturation temperature of 353 F. The samedesign standards are used on the Oakdale 125 psig steam distribution system asthose required for the Main Campus 155 psig steam distribution system.

4. Whenever additional steam loads are to be applied to the steam distributionsystems, an evaluation of the load design requirements and available steamdistribution facilities and operational needs of the steam/power plant and steamdistribution systems must be made. It is requested that the Designer consult withFSG-Utilities-Mechanical Distribution.

5. For applications where it is anticipated that the 20 psig distribution system hasadequate or near adequate capacity for the majority of the year, but not adequateduring peak load periods, a pressure reducing valve booster station shall beconnected from the 155 psig distribution system to maintain a minimum linepressure of 15 psig.

Design & Construction Services Mechanical DistributionThe University of Iowa (1/04) 2.10-1


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A. Pressure Reducing Valves:

1. Pressure reducing valves (PRVs) shall be eccentric plug control valves sized andinstalled to manufacturer's specifications. Manufacturer: Cashco Ranger.(Valves may be provided by FSG out of the project budget if requested.)

2. Valve bodies shall be steel or ductile iron. Cast iron will not be accepted.

3. Valves are to be air operated. Pilot operated valves may be allowed underspecial circumstances. Consult with FSG-Utilities-Mechanical Distribution.

4. PRVs from the high pressure system will always be fail-close. Valves on the lowpressure system may be fail open, at the discretion of FSG-Utilities-MechanicalDistribution and the maintenance staff of the affected building.

5. Valves shall provide Class 6 shutoff unless otherwise approved.

6. Valves shall have flangeless bodies designed to fit between two raised face

flanges. The bodies shall fit between ANSI 300# flanges.

7. Gasket material used on flanges shall be Grafoil or equivalent, rated to 500 F.

8. Pressure reducing stations shall be piped as shown on Drawing SD-1.8. Theblowdown valve shall be piped such that it does not blow on the PRV and can besafely operated while open. No caps are to be used on the blowdown lines,except in building basements.

9. Where the PRV is smaller than line size, the isolation valves shall be at least onestandard pipe size larger than the control valve (up to line size.)

10. Reducers in PRV stations shall be eccentric, or concentric as needed, to avoidhaving points where condensate can build up.

11. Trapping on pressure reducing stations shall be determined by good engineeringdesign based on station configuration.

12. The pilot pressure sensing line shall be tied into the main pipe at least 20 pipediameters downstream of the pressure reducing valve. There shall be a pressuregauge on the pilot line.

13. Installation of a bypass valve shall be determined during the design phase inconsultation with FSG-UTILITIES-MECHANICAL DISTRIBUTION based on theuse of the system. Systems using steam mainly for heating shall generally have

a bypass. Systems using steam mainly for process use shall generally not havea bypass.

B. Steam Trapping Stations:

1. Steam traps on mechanical distribution piping shall be only Armstrong #2011Series. These are inverted bucket traps, with a modular universal body design toallow for easy replacement.



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2. Steam traps are to be modular stainless steel inverted bucket traps. Traps shallhave orifices appropriate to the pressure of the steam line.

3. Each trap will have an upstream block valve, test valve, and strainer, adownstream swing check valve, a test valve, and a block valve, as shown inFigure SD-2.3. There shall be no trap bypasses.

4. Traps shall be piped off of drip legs. Drip leg diameter shall be equal to the pipesize for pipes up to 4" and at least one-half the pipe diameter for pipes over 4".Length of the drip legs should be 1-1/2 times the diameter of the pipe, with aminimum of 12".

5. Drip legs shall be equipped with blowdown valves on the bottom of the drip legequal to the smaller of line size or 2". Where 2 valve will not fit, 1-1/2 valve maybe substituted with FSG-UTILITIES-MECHANICAL DISTRIBUTION approval.Blowdown valves shall be piped from the bottom of the drip leg cap whereverpossible.

6. Blowdown piping on drip legs and strainers shall face away from the blowdownvalve handwheel and shall not discharge onto electrical equipment.

C. Check Valves:

1. All check valves shall have either bronze or stainless steel seats and flappers.

2. Bodies shall be bronze, cast steel or forged steel. Cast iron bodies are notacceptable.

3. All valves on steam shall be 300# class.

4. Manufacturers: Crane, Powell or approved equal.

D. Strainers:

1. All strainers shall have bronze, cast steel or forged steel bodies. Cast iron is notacceptable.

2. Strainers shall have 1/32 screens.

3. The blowdown port of each strainer shall have a pipe nipple with a full port sizedgate valve with no cap.

4. Any strainer on 155 psig steam system shall be 300# class. Any strainer on

20 psig steam system shall be 150# class

5. Manufacturers: Armstrong, Sarco, Hoffman, or approved equal.

E. Piping:

1. Piping material shall be chosen according to the following list:


Steam - All Locations:


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2" & Smaller Schedule 80 A106 Gr B seamless, threaded.2-1/2" & Larger Std Wt A106 Gr B seamless, buttweld.

Condensate in Tunnels and Tankrooms:2" & Smaller Schedule 80 A106 Gr B seamless, threaded2-1/2" & Larger Schedule 10S A312 Type 304L stainless steel.

Condensate in Direct Bury Systems:2" & Smaller Schedule 40S A312 Type 304L stainless steel,

threaded or socket weld2-1/2" & Larger Schedule 10S A312 Type 304L stainless steel

(Depending on surface load and installation method,2-1/2 and larger pipes may need thicker walls.Consult with FSG-UTILITIES-MECHANICALDISTRIBUTION.)

2. Piping shall be sloped 1/4" per 10' of pipe to a drip leg. Pipe shall be slopeddown in the direction of steam flow, where possible.

3. Trapping stations shall be located every 250 feet on all steam lines. Direct burysystems will require steam vaults to access trapping stations.

4. All piping 2-1/2 and larger shall be butt welded, with no backing ring. Weldsshall be visually inspected by a qualified welding inspector.

5. All piping 2 and smaller shall be screwed piping. All flanges on screwed pipingshall be backwelded.

6. All piping 4 and larger on the low pressure or condensate systems, and allpiping over 2 on the high pressure system, shall be analyzed with an appropriatestress analysis program by a qualified engineer to properly size and designhangers and avoid excessive stress in any pipe sections.

7. All piping shall be hydrostatically tested to a minimum of 150# pressure. Testpressure shall be held for 4 hours. Testing shall not be done against a valve withlive steam on the other side without consultation with FSG-UTILITIES-MECHANICAL DISTRIBUTION. Where necessary to test, the piping shall be cutand capped. Welds determined by FSG-UTILITIES-MECHANICALDISTRIBUTION not able to be hydrostatically tested may be requested to beinspected by magnetic particle testing.

8. Piping shall have high point vents to allow complete filling of pipe for thehydrostatic test.

9. Provisions shall be made for blowdown of new steam piping to clean out debris.Provisions are to be shown on design drawings. Blowdown plans are to bedeveloped in consultation with FSG-UTILITIES-MECHANICAL DISTRIBUTION.

10. Provisions for pipe expansion shall be made. Both high and low pressure

systems shall be designed for 500 F. Expansion joints (see Section H) are



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the preferred method. If expansion loops must be used, please inform FSG-UTILITIES-MECHANICAL DISTRIBUTION of the reasons.

F. Fittings:

1. All pipe fittings shall be as follows :

2" & Smaller Threaded forged steel 2000# class.2-1/2" & Larger Standard weight steel buttweld fittings.

2. Threaded systems shall use unions where appropriate. All unions shall beNicholson Uniflex Steel/Stainless Pipe Couplings. Pipe unions shall havereplaceable gaskets.

3. All elbows shall be long radius.

G. Gate Valves:

1. Large Valves (2-1/2" & Larger):

a. Manufacturers: Powell, Newco, Velan, Crane or equal.b. 155 psig Steam: 300# class cast steel, butt weld. 20 psig Steam: 150#class cast steel, butt weld.

c. Hard faced seat rings.d. All valves on a project shall be by the same manufacturer and the same

model.e. Direct-operated valves are preferred over gear-operated valves.f. All valves shall be equipped with operating devices to allow the valves to

be operated from the ground.

2. Small Valves (2" & Smaller):a. Manufacturer: Powell.

b. 155 psig Steam: 300# class screwed bronze. 20 psig Steam: 300# classscrewed bronze.c. Rolled in stainless steel seat rings.d. Powell Model 2377 only.e. All valves on a project shall be by the same manufacturer and the same

model.

H. Expansion Joints:

1. Manufacturers: Adsco Model SO-391-RJ, Yarway Fig. No. 6239, Hyspan 6500series and ATS Thermal Pac Series P2 Ball Joints. All expansion joints on aproject shall be by the same manufacturer and the same model.

2. All expansion joints shall be piston or ball type joints with steel bodies andchromium plated steel slips.

3. Joints shall have internal and external guides integral with joint gland and body.Joints shall be equipped with limit stop.

4. Joints shall not have an anchor foot.



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5. Joint shall allow the addition of new packing while joint is in service under full linepressure. The packing ram shall be steel, with no shutoff valve.

6. Joints shall have butt weld ends.

7. Joint travel shall be based on 550 F operating temperature. Joints shall be

pre-pressed to allow shrinkage down to 0 F.

8. Drain plugs shall be seal welded shut.

9. Joints shall be installed per manufacturers specifications.

I. Safety Valves:

1. Sized to State of Iowa Codes and ASME Section VIII Unfired Pressure VesselCode.

2. Multiple small valves may be used in lieu of a single larger valve.

3. Small safety valves (2-1/2 outlet or smaller) shall be Kunkle Figure 6010 orequal.

4. Large safety valves (3 outlet or larger) shall be Kunkle Figure 300 or equal.

5. Each safety valve shall have an individual vent pipe to outside. Consult withFSG-UTILITIES-MECHANICAL DISTRIBUTION on vent pipe size and routing.

6. Safety valve generally not to be hard piped to vent line. All safety valves largerthan 2 shall have cast drip plates (Kunkle Figure 299 or equal) at the base of thevent pipe, with drain holes piped to a suitable drain.

J. Condensate Pumps:

1. Pumps shall be electric duplex type.

2. Manufacturers: Backos, Johnson, ITT, Spirax, Sarco, Clark Reliance or equal.Pump shall be installed per manufacturers specifications.

3. Condensate tanks shall be vented. Vent discharge location shall be coordinatedwith FSG-UTILITIES-MECHANICAL DISTRIBUTION (and Operations &Maintenance personnel in building).

K. Gauges:

1. McDaniel Gauges or equivalent stainless steel gauge.

2. Face Style: 4" or larger.

3. Range Selection: 20 psig system gauges shall be 0-30 (psig). Medium pressure(20-90 psig) gauges shall be 0-100 (psig). 155 psig system gauges shall be 0-200 (psig).



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4. Mounting: Standard bottom connection.

L. Steam Flow Meters: All buildings have their steam usage monitored by vortex sheddingsteam meters.

1. Steam flow meters, pressure transmitter, and temperature transmitter will be

provided by the FSG-UTILITIES-MECHANICAL DISTRIBUTION.

2. Steam meters shall to be installed in long straight runs of pipe to ensure evenflow.a. Meters shall be installed with 20 pipe diameters of straight, unobstructed

pipe upstream of the meter, and 10 pipe diameters of straight,unobstructed pipe downstream of the meter.

b. If the total of 30 pipe diameters absolutely cannot be accommodated,straightening vanes might be approved by FSG-UTILITIES-MECHANICAL DISTRIBUTION. When straightening vanes are used,80% of the available straight pipe shall be upstream of the meter and20% of the available straight pipe shall be downstream of the meter.

3. The steam meter shall be aligned with the direction of the flow.

4. Meters and associated piping shall be sized to provide steam flow rates ofbetween 5 and 100 fps. Meters may go upstream or downstream of pressurereducing valve, depending on pressures and flows. Consult with FSG-UTILITIES-MECHANICAL DISTRIBUTION if questions arise.

5. The steam meters used are of three different styles, based on the size of the pipethe meters are used on. Steam metering stations may be installed in 2", 3", 4",and all larger sized pipe.a. 2" and 3" steam meters are flanged. Mating flanges to be used are ANSI

Class 300. Flange bolts shall extend through both meter flanges. SeeFigure 15251.12.6.1 for installation details.b. 4" steam meters are a flangeless design. The meter shall be sandwiched

between two ANSI Class 300 flanges. See Figure 15251.12.6.1 forinstallation details.

c. Meters to be installed in lines larger than 4" are an insertion type meter.The pipe shall be prepared with a 2" Thread-O-Let, with a pipe tap of1-7/8" minimum. There shall be a minimum of 48" head clearance abovethe tap to allow for installation and removal of the meter. See Figure12521.12.6.3 for installation details.

6. Each steam meter installation shall have a pressure transmitter and atemperature transmitter. The pressure and temperature transmitters shall bebetween 2.5 to 3.5 pipe diameters downstream of the meter and spaced apart asrequired for tapping. See Figure 15251.12.6.1 for installation details.

7. All meters shall have isolation and bypass valves as shown on the installationdrawings.

M. Pressure Transmitters:



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1. Pressure transmitters will be provided by the FSG-UTILITIES-MECHANICALDISTRIBUTION.

2. Pressure transmitters shall be installed with a shut-off valve, pigtail, and pressuregauge as indicated under Section L.7.

N. Temperature Transmitters:

1. Temperature transmitters will be provided by the FSG-UTILITIES-MECHANICALDISTRIBUTION.

2. Stainless steel thermowell for temperature transmitter shall be provided byFSG-UTILITIES-MECHANICAL DISTRIBUTION and will have enough collar toprotrude through the insulation.

O. Burial Selection:

1. Main Services - Walk Tunnels: Steam lines designated as a main campus steam

service by FSG-UTILITIES-MECHANICAL DISTRIBUTION shall be installed onlyin walk tunnels for reliability, maintainability and potential to be upgraded. Themain service tunnels shall have room enough to transport any requiredreplacement parts between the pipe supports, with clearance space for fingers,heads, and carrying of devices.a. Tunnel floors shall be positively sloped towards a drain or sump.b. Tunnels shall be ventilated with supply fans controlled by a thermostat

with an On/Off/Auto switch.c. Tunnel entrances shall be hinged, spring assisted Bilco doors or

equivalent. Tunnel entrances shall not be placed under roads. Doorsshall be key lockable. Dead bolt locks are not acceptable. No key shallbe required to open door from inside, and exit lever shall be easily

accessible.d. At tunnel locations where serviceable items are located, tunnel chambersshall be installed with surface access.

e. Surface access shall allow hands-free upright entrance whereverpossible.

f. All tunnels shall have lights and outlets for the length of the tunnel onseparate circuits.

g. No plastic expansion anchors shall be used in the tunnel, even forconduit.

h. Emergency lighting is not required. All tunnels entrants are required tohave flashlights.

i. All tunnel entrances shall have aluminum OSHA notice signs statingEntry into Utility Tunnels requires approval! Daytime 335-5156/335-6103; Nights/Weekends 335-5022 (page Mechanical Distribution on-call person) mounted just inside the entrance.

2. Branch Services - Tunnels or Direct Burial: While no direct buried pipingsystems are acceptable to FSG-UTILITIES-MECHANICAL DISTRIBUTION, werecognize the fact that in many cases it is not economically feasible to constructtunnels. Based on the service size, location and other conditions a decisionmust be made as to type of branch service.



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Following are our preferences for each type of system. We may be willing to lookat alternate systems that are not discussed below, but would be reluctant toapprove downgraded versions of those discussed. Please note that while all ofthese options have their uses, they are not all interchangeable or proper for alllocations or designs. Consult with FSG-UTILITIES-MECHANICALDISTRIBUTION for selection of appropriate system.

a. Pre-Insulated Piping: Pre-insulated piping generally consists of a steelcarrier pipe, insulation and an outer casing pipe. The system is pre-designed by the manufacturer and fabricated off-site. It is assembled inthe field like a jigsaw puzzle. Installation is tolerant of contractor error.High difficulty of field modification. Usually has a lead time of 8 weeksafter receipt of order.1) Preferred System: Permapipe Multi-Therm 500 or equal.

Minimum System: Permapipe Escon-A or equal.2) Acceptable Manufacturers: Permapipe/Ricwil, Rovanco,

Thermacore.3) Steam and condensate shall be installed in separate casing pipes.4) Trapping vaults on the system shall be no more than 250 feet

apart. See Section P for vault details. Vaults are more than justlocations for traps and expansion joints. They also allow places inthe system for future tie-ins and allow adequate troubleshooting ofsystem leaks.

5) Provision for pipe expansion shall be made. Expansion joints(Section H) in a vault are the preferred method. If expansionloops must be used, inform FSG-UTILITIES-MECHANICALDISTRIBUTION of the reasons. Expansion loops take up moreground space, save no money, provide a likely place to startleaks, and prevent new pipe from being slid into the old casingwithout excavation.

6) All wall penetrations shall be sealed with Thunderline Linkseals or

equivalent.7) Casing pipe shall be air pressure tested.

b. Direct Buried FoamGlas: This consists of a steel carrier pipe with fieldapplied FoamGlas insulation and a heat sealed protective jacket. Mustbe fully designed by project engineer. This system is all field fabricated.This system is not tolerant of contractor error. This system may also notbe as watertight at wall penetrations.1) Steam and condensate pipe shall be insulated separately with

adequate thickness Foamglas insulation.2) Insulation shall be held onto pipe with wire. Outer jacket shall not

be used to hold insulation in place.

3) Outer jacket shall be heat sealed Pittwrap. Standard bituthene orself-sealing wrap shall not be used. Install jacket permanufacturers instructions.

4) Wall penetrations shall have outer jacket extended through wallpenetration. Urethane foam shall be used to seal between the

jacket and the concrete.5) Trapping vaults on the system shall be no more than 250 feet

apart. See Section P for vault details. Vaults are more than justlocations for traps and expansion joints. They also allow places in



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the system for future tie-ins and allow adequate troubleshooting ofsystem leaks.

6) No expansion loops shall be used on this system.7) Flowable fill or compacted sand shall be used as bedding.8) Full-time engineering supervision is required during installation, as

faulty installation cannot be detected by any post-construction test

methods.

c. Dri-Therm Envelope: Dri-Therm is a fine, white mineral powder designedto enclose piping in a water-repellent insulating envelope. This consistsof a steel carrier pipe bedded and backfilled in 6-10 of Dri-Therm.Dri-Therm is willing to assist the project engineer with design. Thissystem is not tolerant of contractor error. This system may also not be aswatertight at wall penetrations.1) Steam and condensate pipe may be encased in same Dri-Therm

envelope.2) The pipe system and supports must be designed by Dri-Therm.3) Trapping vaults on the system are to be no more than 250 feet

apart. See Section P for vault details.4) Provision for pipe expansion shall be made. Expansion joints

(Section H) in a vault are the preferred method. If expansionloops must be used, inform FSG-UTILITIES-MECHANICALDISTRIBUTION of the reasons. Expansion loops take up moreground space, save no money, and provide a likely place to startleaks.

5) Full-time engineering supervision is required during installation, asfaulty installation cannot be detected by any post-construction testmethods.

P. Vault Design:

1. All vaults shall be designed with enough room to do the work required.

2. All vaults shall be provided with power and light.

3. All vaults shall have positive ventilation controlled by a thermostat with On-Off-Auto option switch..

4. All vaults shall have either a drain to a storm sewer (preferred) or a permanentlyinstalled sump pump and discharge piping.

5. All vaults shall have spring-assisted access doors (Bilco or equal). Manholecovers are not acceptable. Doors shall be lockable with a key. In vaults, deadbolts are acceptable.

6. All vaults shall be cast-in-place concrete.

7. All vaults shall have a Q-door when not in driveable area.

8. All vaults shall have a H-20 J-door when in driveable area.



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9. All vault doors shall be sized to allow largest equipment in and out.

10. All vaults shall have a painted or galvanized ladder.

11. Power:a. All vaults shall have at least one outlet and one switched light. Outlet

shall be sized to operate pump and saw-z-all.

12. Drainage:a. All vaults shall have a gravity drain wherever possible.b. All vaults shall have a sump hole at low point, ideally near the entrance.

Sump hole shall be 24 in diameter and 24 deep.

13. Ventilation:a. Cold Hole (a hole in which no high temperature lines are present):

1) A cold hole shall have power and small airflow for humidity controlwith freezestat.

b. Hot Hole (a hole in which high temperature lines are present):

1) A hot hole shall have large power flow with a freezestat.

14. All vaults may require two separate openings, or one opening and grate inQ-door.

15. All small openings in vaults shall be manholes with rings.

16. All wall piping penetrations shall be sealed with link seals.

17. All outside walls shall be waterproofed. Match existing building waterproofing.

18. All vault ceilings shall be waterproofed.

19. All vault supports for process piping and equipment shall be stainless steel.

20. All vault supports for maintainable items shall be galvanized or painted.

21. All vault surface drainage shall be routed away from all openings.

22. There shall be controls for ventilation of all vaults.

23. Power:a. All vaults shall have a single speed fan with thermostat control fan to

have On-Off-Auto switch in vault.

24. All vault ventilation shall be either in vault or remote louvered penthouses.

25. All vault air ducts to louvered penthouses shall be ductile iron (push joint).

26. All vault drain piping shall be:a. Cold Vault: PVC.b. Hot Vault: Steel in vault; ductile iron pipe in ground.


Q. Pipe Support:


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1. All portions of pipe stanchions within 12" of concrete shall be 304L stainlesssteel.

2. All anchors shall be insulated from floor to ceiling.

R. Insulation:

1. Insulation shall be provided on all pipes, ducts and equipment where:a. Heat transmitted will significantly affect the ambient temperature in

spaces requiring temperature control.b. Heating and/or cooling ability will be significantly affected due to heat flow

into or out of the pipe or duct.c. Condensation will occur as a result of the material surface temperature

approaching the dewpoint of the ambient air.d. Significant energy loss would result from heat transfer justifying the cost

of insulation.e. Personal injury may result.

2. Insulation shall not be installed on steam traps and condensate return pumps.

3. All exterior piping insulation systems shall be specified with a 0.019-inchstainless steel jacket.

STEAM TUNNEL INSULATION

1. All steam lines in tunnels will have the following insulation:a. 850 Certainteed fiberglass insulation, 3-1/2" thick on high pressure

steam; 2-1/2" thick on low pressure steam. Where the required size ofinsulation is not possible, the largest size of 850 Certainteed fiberglassinsulation possible shall be used.

b. In addition to the fiberglass insulation with the vapor barrier jacket, theinsulation shall be covered with fiberglass cloth and CP-11 vi-cryl mastic.Mastic shall be applied thick enough that cloth pattern shall not be visible.

c. Insulation shall be installed in two layers, using staggered joints andseams.

2. All condensate lines in tunnels shall have the following insulation:a. 1" of 850 Certainteed fiberglass insulation.b. In addition to the fiberglass insulation with the vapor barrier jacket, the

insulation shall be covered with fiberglass cloth and CP-11 vi-cryl mastic.Mastic shall be applied thick enough that cloth pattern shall not be visible.

3. At any point in the tunnel where there is an entrance to the tunnel, fan dischargeonto the insulation, or grating openings, there shall be a 0.019 inch stainlesssteel jacket installed around all insulated pipes. All seams in the jackets shall beplaced facing downward.

4. If the pipe is held in place with a spider guide that does not have sufficientclearance to allow at least 3/4 clearance between the insulation and the outerring, the following procedures shall be used:



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a. The insulation shall neck down to a single layer approximately 6 beforeand after the guide.

b. The top layer of insulation shall be beveled at a 45 degree angle to allowfor a smooth transition to a single layer.

c. The individual pieces of insulation that are placed between the legs of thespider guide shall extend past the spider legs so that they may be bound

firmly into place with cloth and mastic wrapped around the pipe.

STEAM VAULT INSULATION

1. All steam lines in vaults shall have the following insulation:a. 3-1/2" of non-asbestos containing calcium silicate insulation with the

exception where 3-1/2" of insulation is not possible, then the largest sizeof non-asbestos containing calcium silicate insulation shall be used.

b. In addition, there shall be two layers of insulation with staggered jointsand seams.

c. Jackets shall be 0.019 inch stainless steel. All seams shall facedownward.

2. All condensate lines in vaults shall have the following insulation:a. Insulation shall be 1" calcium silicate, using manufacturers listed below.b. Jackets shall be 0.019 inch stainless steel. All seams shall face

downward.

3. The non-asbestos containing insulation shall meet or exceed the standards of thefollowing brands:a. Johns Manville - Kaylo T-12b. Pabco-Cal Tempc. Manson-Cal-Maxd. Temperlite 1200

e. Owens-Corning Pink

EXPANSION JOINT INSULATION

1. All expansion joints shall have removable/reusable insulation covers that coverthe expansion joint from weld to weld. The expansion joint covers are required tomeet or exceed the following:a. The outer jacket shall be Steamguard 1-Teflon coated Nomex cloth

7 oz./sq. yard x 0.010" thick.b. The gusset shall be Steamguard 1-Teflon coated Nomex cloth 7 oz./sq.

yard x 0.010" thick.c. The inter jacket shall be stainless steal crimped mesh.

d. The insulation shall be 2" thick, minimum of 6# density, ceramic wool.e. The sewing thread shall be 3-ply 304 stainless steel and pure Nomexthread.

f. The seam fasteners shall be stainless steel lacing hooks.g. ID tags shall be 304 stainless steel, embossed lettering.h. All the rest of the hardware shall be 304 stainless steel.i. Hog ring construction shall not be used.

j. Provisions shall be made for the packing cylinders to ensure snug fitalong the entire expansion joint.



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k. Factory-made covers designed especially for the purchased expansionjoints may be approved by the Owner even if some of the abovespecifications are not met.

PREINSULATED PIPING INSULATION

1. All lines in preinsulated piping systems shall have one of the following types ofinsulation, based on the manufacturers standard.a. 850 Certainteed fiberglass insulation (or approved equal), mineral wool,

calcium silicate, or Foam-Glas.b. High Pressure Steam: 3-1/2" thick.c. Low Pressure Steam: 2-1/2" thick .d. Condensate: 1 thick.e. The different insulating values do not affect the thickness of insulation

desired.

II. WATER DISTRIBUTION SYSTEM

System Description:

The Water Plant currently produces soft water and distributes it to the campus through a largenetwork of piping. The majority of the system is looped, but there are some radial feeds.Looped systems are preferred for reliability and maintainability. There are also severalconnections to the City of Iowa City water lines, used to feed or be fed in emergencies.

Whenever additional water loads are to be applied to the water distribution systems, anevaluation of the load design requirements and available water distribution facilities andoperational needs of the Water Plant and water distribution systems must be made. It isrequested that the Designer consult with FSG-Utilities-Mechanical Distribution.

A. Water Pipe:

1. Ductile iron piping shall be class 350 restrained joint piping for 18 and smaller.For 20 and larger pipe, class shall be determined based on pipe layingconditions.

2. Pipe shall be cement lined.

a. All changes in direction shall be made with 45, 22-1/2, or 11-1/4

bends. 90 elbows shall be used only with Owner's approval.

3. Acceptable Manufacturers: Griffin - Snap Lok, U.S. Pipe TR Flex, Clow - SuperLock, or American Pipe.

4. All water pipe shall be encased in a polyethylene sheathing.

5. All field cut joints shall be mechanical joint with Megalug series 1100 restraint.Manufacturers field kit shall not be used.

6. Hydrants shall be Mueller Super Centurion 200, Model A-423.



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7. Valves 14 and smaller shall be Clow F-6100 resilient wedge gate valve orapproved equal.

8. Valves 16 and larger shall be gear-operated butterfly valves.

9. All pipe shall be laid in a sand bed and shall have at least a 12 sand envelope.

10. Disinfection procedures shall be stated in specifications to conform to AWWA.Disinfection shall be done before hydrotest.

11. Flushing instructions shall be explicit in Drawings, including source of water,outlet point and final destination of water.

12. Hydrotest: FSG-Utilities-Mechanical Distribution has the following specialrequirements for hydrotesting:a. Hydrotest piping to 150 psig.b. Where possible, hydrotest shall be made against capped ends.c. FSG-Utilities-Mechanical Distribution shall witness first attempt at hydro.

There shall be no pre-test.d. Test shall be for 4 hours.e. Pipe may only lose 5 psig.f. Generally, the leakage rate criterion shall not to allowed.

13. All wall penetrations shall be sealed with Link-seals.

14. All piping shall be anchored to the wall at wall penetrations.

III. CHILLED WATER DISTRIBUTION SYSTEM

System Description:

Currently, the chilled water distribution system uses the same specifications as the domesticwater system except as noted below:

1. Disinfection is not required.

2. All valves on chilled water shall be gear-operated butterfly valves.

IV. SEWER COLLECTION SYSTEM

System Description:

The campus sanitary system collects sanitary sewage from all campus buildings from

connections at manholes. The campus sewers then discharge into the Citys sewer lines atseveral places for the final journey to the City sewage plant.

The campus storm sewer system collects storm water and some cooling tower blowdown fromall over campus and directs it to many locations to drain into the Iowa River.


Whenever additional sewage loads are to be added to the sewer collection system, anevaluation of the load design requirements and available sewer collection facilities must bemade. It is requested that the Designer consult with FSG-Utilities-Mechanical Distribution.


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A. Sewer Pipe: Select the appropriate pipe from the choices below. FSG-Utilities-Mechanical Distributions preference is for push joint PVC sewer pipe, but there arelocations where this is not an appropriate choice. Cement sewer pipe shall be used onlywhere absolutely necessary.

1. SDR 35 PVC push joint pipe.

2. PVC cement filled truss pipe.

3. Ductile iron pipe with restrained joints. See Section on water piping.

4. Precast concrete pipe.

5. Galvanized spiral pipe shall not to be used.



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The University of IowaMechanical Distribution

Notes for 2 - 4 Meter Installation, 6/11/97 Rev 2

1. Meters must be installed in straight piping. The piping shall be free from bends, reducers,

valves, and branch lines for a distance of 20 pipe diameters upstream from the meter and 10pipe diameters downstream of the meter. The diameter of the piping shall be the same asthe meter size.

2. Meters have flow direction arrows on them that need to be observed. There are 3 sizes of in-line meters, 2, 3, and 4. There are no other sizes under 4. The 4 meters have wafer stylebodies. The 2 and 3 meters have flanged bodies. Flanges should be 300# raised face.Meter will be provided by FSG-Utilities and installed by contractor.

3. Use line size gate valves, butt weld steel for 3 and larger, Powell Model 2377 for 2.

4. 1/2 NPT thread-o-let is for pressure tap assembly (detailed on Pressure Tap - SteamMetering). 3/4 NPT thread-o-let is for a thermowell to be at least 5 pipe diametersdownstream of meter. In 2 piping, the 3/4 thread-o-let is to be eliminated and replaced with

a 2x3/4 coupling in the end of a tee downstream of the 10 pipe diameter straight run.Thermowell to be provided by FSG-Utilities.

5. 2" Powell valve model 2377 for the by-pass.

6. 2" by-pass around the meter installation.

Design Notes

Sizing :Steam meters are to be sized for a steam velocity of 5 minimum feet per second of steam flowand a maximum velocity of 125 feet per second.Electronics:

The sensors in the meter station consist of a pressure transmitter, a temperature transmitter,

and a steam flow meter, all provided by FSG-Utilities. The sensors require conduit and wiring toa central location which will be an existing PLC or a new PLC. The wiring destination and PLCcomponents that the project needs to cover must be coordinated with FSG-Utilities on a percase basis. A separate specification covers the wiring and PLC required.



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Notes for - 6 and Larger Meter Installation 6/12/97 Rev 2

1. Meters must be installed in straight piping. The piping shall, be free from bends, reducers,

shall valves, and branch lines for a distance of 20 pipe diameters upstream from the meterand 10 pipe diameters downstream of the meter.

2. Insertion style meter provided and installed by FSG - Utilities.

3. The distance from the flange to any wall or other obstruction be at minimum of 43".

4. The 3/4" Thread-O-Let and 1/2" Thread-O-Let. Materials provided by FSG - Utilities, installedby contractor. For the pressure tap assembly see the Pressure Tap Figure.

5. 2" Thread-O-Let with a 1 7/8" minimum tap, provided by FSG - Utilities and installed bycontractor.

6. 2" XH Steel nipple 4 long, provided by FSG - Utilities and installed by contractor.

7. 2" gate valve to be Powell Model 2377, provided by FSG - Utilities and installed bycontractor.

8. 2" XH Steel nipple 6 long, provided by FSG - Utilities and installed by contractor.

9. Flange 300# raised face, provided by FSG - Utilities and installed by contractor.

Design Notes

Sizing :

Steam meters are to be sized for a minimum steam velocity of 5 feet per second of steam flowand a maximum velocity of 125 feet per second.

Electronics:

The sensors in the meter station consist of a pressure transmitter, a temperature transmitter,and a steam flow meter, all provided by FSG-Utilities. The sensors require conduit and wiring toa central location which will be an existing PLC or a new PLC. The wiring destination and PLCcomponents that the project needs to cover must be coordinated with FSG-Utilities on a percase basis. A separate specification covers the wiring and PLC required.



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Notes for - Pressure Tap - Steam Meter 6/12/97 Rev 3

1. 1/2" XH steel nipple; length sufficient so valve handle is free from insulation.

2. 1/" 300# Class Bronze Valve, Powell Model 2377.

3. 1/2" XH steel nipple, 2" long.

4. 1/2" to 1/4" 2000# steel coupling (no bushings shall be used).

5. 1/4" steel pigtail.

6. 1/4" x 1/4" x 1/4" 2000# steel tee.

7. Ashcroft pressure transmitter (provided by FSG-Utilities).

8. Pressure gauge, piped so it can be read from ground (provided by FSG-Utilities).

Design Notes

Electronics:The sensors in the meter station consist of a pressure transmitter, a temperature transmitter,and a steam flow meter, all provided by FSG-Utilities. The sensors require conduit and wiring toa central location which will be an existing PLC or a new PLC. The wiring destination and PLCcomponents that the project needs to cover must be coordinated with FSG-Utilities on a percase basis. A separate specification covers the wiring and PLC required.



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DESIGN REFERENCE MANUALDESIGN REFERENCE MANUAL

Steam Line Mechanical Distribution

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