Modular Boilers Only... · 2018-11-12 · ASME Section IV and CSD-1 Hot Water Heating Module...

Modular Boilers Controls and Instrumentation

Courtesy of Slant/Fin

NB Members Technical Meeting 2016 1

ASME Section IV and CSD-1

Steam

Module Assembled Modular Boiler

Pressure Gage HG-602; One required Range 1-1/2 to 3-1/2 times

low PRV set pressure

Not required

Pressure Relief Device HG-701; “V” or “HV” Valve (s) Not Required

Water Gage Glass HG-603; one Not Required

Pressure Controls HG-605; CW-620 Operating Control Limit Control

Low-Water Fuel Cutoff HG-606;

CW-610

One One

Heat Generating Apparatus HG-

640; CF-900

ANSI Z21.13, ASME CSD-1, UL Standards ANSI/UL 732, ANSI Z21.10.3/CSA 4.3, &

several UL Standards

Feedwater connection HG-705 Split from manifold Manifold feeds modules

Blowoff valve sized in Table

HG-715;

Minimum of one Not Required

Manifold/ header HG-716 Each module connection, no intervening

valves

Collecting from each module

Combustion Side control Part CF Burner and fuel Train Not applicable

Manual Shut down switch CE-110 Provided on each module Required on Modular boiler


ASME Section IV and CSD-1

Hot Water Heating


Pressure Relief Device HG-700 “V” or “HV” Valve Not Required

Pressure / Altitude Gage HG-611 Minimum One Required Not Required

Water Gage Glass Not required Not Required

Temperature Controls HG-615;

CW-640

Operating control Limit control)

Thermometer HG-612 One Required One Required

Make up with check valve HG-705 Not Required One on manifold


CW-630

Not Required One

Heat Generating Apparatus

HG-640; CF-900

ANSI Z21.13, ASME CSD-1, UL

Standards

ANSI/UL 732, ANSI Z21.10.3/CSA

4.3, & several UL Standards

Drain valve HG-715 One required none

Provision for Thermal Expansion

HG-709

Not Required One for system

Stop valves HG-710 Not Required On headers

Manifold/ header HG-716 No intervening valves On supply / return

Combustion side control Part CF Burner and fuel train Not applicable

Manual Shut down switch CE-110 Provided on each module Required on modular boiler


Hot Water Modular Boiler



ASME Section IV and CSD-1 and

NBIC Part 1- 3.7.8, 3.8.1.6

Steam


Pressure Gage HG-602; One required Range 1-1/2 to 3-1/2 times

low PRV set pressure

Not required

Pressure Relief Device HG-701; “V” or “HV” Valve (s) Not Required

Water Gage Glass HG-603; one Not Required

Pressure Controls HG-605; CW-620 Operating Control Limit Control


CW-610

One One

Heat Generating Apparatus HG-

640; CF-900

ANSI Z21.13, ASME CSD-1, UL Standards ANSI/UL 732, ANSI Z21.10.3/CSA 4.3, &

several UL Standards

Feedwater connection HG-705 Split from manifold Manifold feeds modules

Blowoff valve sized in Table

HG-715;

Minimum of one Not Required

Manifold/ header HG-716 Each module connection, no intervening

valves

Collecting from each module

Combustion Side control Part CF Burner and fuel Train Not applicable

Manual Shut down switch CE-110 Provided on each module Required on Modular boiler


ASME Section IV and CSD-1 and NBIC

Part 1- 3.7.8, 3.8.2.5

Hot Water Heating


Pressure Relief Device HG-700 “V” or “HV” Valve Not Required

Pressure / Altitude Gage HG-611 Minimum One Required Not Required

Water Gage Glass Not required Not Required

Temperature Controls HG-615;

CW-640

Operating control Limit control)

Thermometer HG-612 One Required One Required

Make up with check valve HG-705 Not Required One on manifold


CW-630

Not Required One

Heat Generating Apparatus

HG-640; CF-900

ANSI Z21.13, ASME CSD-1, UL

Standards

ANSI/UL 732, ANSI Z21.10.3/CSA

4.3, & several UL Standards

Drain valve HG-715 One required none

Provision for Thermal Expansion

HG-709

Not Required One for system

Stop valves HG-710 Not Required On headers

Manifold/ header HG-716 No intervening valves On supply / return

Combustion side control Part CF Burner and fuel train Not applicable

Manual Shut down switch CE-110 Provided on each module Required on modular boiler NB Members Technical Meeting 2016 8

Chief’s Technical Meeting Presented by:

Gary Scribner – Manager of Technical Services

October 2016

Gas Train Venting

2 The National Board of Boiler and Pressure Vessel Inspectors

Gas Train Venting

• Vent Valves

• Vent Lines

• Vent Valve Lines

• Bleed Lines

• Double Block and Bleed

• Regulator Vent


Gas Train Venting

• State Regulations

• NFPA 54

• NFPA 85

• CSD-1


• A vent line is a section of piping or tubing that conveys the

release of gases from fuel train components.

Vent Line

• A vent line is connected to components such as balancing

diaphragm’s that only expel gas when there is component

failure

Vent Line

Regulator Vent

• The opening in the atmospheric side of the regulator

housing permitting the in and out movement of air to

compensate for the movement of the regulator diaphragm

(2012 NFPA 54 3.3.107.3)


• Regulator vents are

always connected to

a vent line unless

they have a vent

limiter installed

Vent on Pressure Switch


• A vent valve is a normally open, power-closed valve that is

piped between the two safety shutoff valves and vented to

a safe point of discharge (also known as the bleed in a

double block and bleed)

Vent Valve

• A vent valve line is a section of piping that conveys the

release of gas from an automatic or manually operated vent

valve

Vent Valve Line

Bleed Line

• A bleed line is a section of piping or tubing that

conveys the release of gas from a fuel train

component, which periodically releases gas

pressure to the atmosphere in order to operate

properly


Relief Line & Feedback Line

• The term relief line is not currently defined in CSD-1.

However, the relief line is the line from the overpressure

protection device in CF-161 and CF-190(d)

• A feedback line is a section of piping or tubing that normally

communicates air pressure from a point of reference to the

air pressure side of a diaphragm of fuel train component,

but could contain gas under abnormal conditions; or a

section of piping or tubing that communicates flue or gas

pressure from one point of reference to another point of

reference.


Combustion Chamber and Flue Passages

• A combustion chamber is the portion of the boiler enclosure

into which the fuel is fed, ignited, and burned

• Also referred to as a furnace or firebox

• A flue passage is the cavities (e.g., flue, exhaust, or vent

system) that convey the products of combustion from the

boiler combustion chamber to an approved location

• Also referred to as breeching


Safe Point of Discharge

• Question: What is the definition of ‘safe point of discharge’?

• According to the NBIC, a safe point of discharge is a location

that will not cause property damage, equipment damage, or

create a health or safety threat to personnel in the event of

discharge


• Vent lines

• Bleed lines

• Gas-pressure relief lines

• Vent valve lines

• Feedback lines for fuel train components

CF-190 Requirements

(a) Vent Lines

(1) Gas-pressure regulators, combination gas controls,

pressure interlock switches, and all other fuel train

components requiring atmospheric air pressure to balance a

diaphragm shall have the atmospheric side of the diaphragm

connected to a vent line that shall be piped by the installer to

the outdoors at a safe point of discharge as determined by the

authority having jurisdiction unless otherwise allowed in CF-

190(c) or CF-190(h).

CF-190 – Vent Lines

9.1.19 (1)- Appliance pressure regulators requiring access to

the atmosphere for successful operation shall be equipped

with vent piping leading outdoors or, if the regulator vent is an

integral part of the appliance, into the combustion chamber

adjacent to a continuous pilot, unless constructed or equipped

with a vent-limiting means to limit the escape of gas from the

vent opening in the event of a diaphragm failure.

NFPA-54 – Vent Lines

CSD-1 CF-190 –(c)

Components With Vent Limiters. A listed and labeled gas-

pressure regulator, combination gas control, pressure

interlock switch, or other fuel train component incorporating a

vent limiter shall be permitted to vent directly into ambient

space.

NFPA 54 9.1.19 (2)

Vent-limiting means shall be employed on listed appliance

pressure regulators only.

Vent Limiters

Purpose- To limit the amount of gas released in the event of

diaphragm failure to 1 cu. Ft. of gas per hour. The reasoning is

that normal ventilation of the space would be able to safely

remove the gas venting through a vent limiter.

Other considerations – multiple vent limiters in one space.

Vent Limiters

(b) Bleed Lines

(1) Gas-pressure regulators, combination gas controls,

pressure interlock switches, or all other fuel train components

that use an atmospheric diaphragm and periodically release

gas into the atmosphere in order to properly operate shall

have the atmospheric side of the diaphragm connected to a

bleed line that shall be piped by the installer to the outdoors

at a safe point of discharge as determined by the authority

having jurisdiction unless otherwise allowed in CF-190(c) or

CF-190(h).

CF-190 – Bleed Lines

9.1.20 (1) – Diaphragm-type valves shall be equipped to

convey bleed gas to the outdoors or into the combustion

chamber adjacent to a continuous pilot.

9.1.20(2) – In the case of bleed lines leading outdoors, means

shall be employed to prevent water from entering this piping

and also to prevent blockage of vents by insects and foreign

matter.

NFPA 54 – Bleed Lines

(d) Gas-Pressure Relief Lines

(1) If an overpressure protection device incorporating a gas-pressure relief valve is installed, the outlet of the gas-pressure relief valve shall be connected to a gas-pressure relief line that shall be piped by the installer to the outdoors at a safe point of discharge as determined by the authority having jurisdiction.

(2) The gas-pressure relief line shall be sized in accordance with the component manufacturer ’s instructions and shall be at least the same size as the outlet connection of the gas-pressure relief valve

(3) Where there is more than one gas-pressure relief valve at a location, each gas-pressure relief valve shall have a separate relief line piped by the installer to the outdoors at a safe point of discharge as determined by the authority having jurisdiction unless otherwise permitted by CF-190(f).

CF-190 – Gas-Pressure Relief Lines

(e) Lines From Vent Valves

(1) A vent valve, if installed, shall be connected to

a vent valve line that shall be piped by the installer to

the outdoors at a safe point of discharge as determined

by the authority having jurisdiction.

(2) The vent valve line shall be at least the same

size as the outlet connection of the vent valve.

(3) Where there is more than one vent valve at a

location, each vent valve shall be piped by the installer

to the outdoors at a safe point of discharge as determined by the authority having jurisdiction unless otherwise permitted by CF-190(f).

CF-190 – Lines from Vent Valves

(f) Manifolding of Lines. If approved by the authority having

jurisdiction, the manifolding of lines of the same type shall be

permitted, and the manifolding of vent lines and bleed lines

shall be permitted. In order to minimize backpressure in the

event of gas being released through the manifolded line, the

manifolded line shall have a cross-sectional area not less than

the area of the largest branch line directly piped to the

manifolded line plus 50% of the additional cross-sectional

areas of the manifolded branch lines.

CF-190 – Manifolding of Lines

(f) Manifolding of lines of the following types shall be

permitted:

• 1. Manifolding of vent lines with vent lines on the same

boiler

• 2. Manifolding of bleed lines with bleed lines on the same

boiler

• 3. Manifolding of vent lines and bleed lines shall be on the

same boiler


Manifolding of lines of the following types shall not be

permitted:

(1) the manifolding of gas-pressure relief lines with vent lines,

bleed lines, or vent valve lines.

(2) the manifolding of vent valve lines with vent lines or bleed

lines

(3) the manifolding of vent lines, bleed lines, gas pressure

relief lines, and vent valve lines of one boiler unit to any lines

of another boiler unit.


CF-190 (g) No vent line, bleed line, gas-pressure relief line, or vent valve line shall connect to a boiler’s flue passages.

NFPA 54, 9.1.19 (4)

Under no circumstances shall a regulator be vented to the appliance flue or exhaust system.

NFPA 54, 9.1.20.(3)

Bleed lines shall not terminate in the appliance flue or exhaust system

CF-190 and NFPA 54 – Connecting Lines to

Flue Passages

(h) Points of Discharge: Outdoor Requirements, Special

Exceptions, and Prohibited Practices

(1) Unless otherwise terminated as permitted by CF-190(h)(2)

or CF-190(h)(4), vent lines, bleed lines, gas-pressure relief

lines, or vent valve lines shall have provisions to be piped by

the installer to the outdoors at a safe point of discharge as

determined by the authority having jurisdiction. A means shall

be provided at the point of discharge to prevent stoppage of

the lines by foreign material, moisture, or insects.

CF-190 – Points of Discharge

CF-190 Points of Discharge


(2) A combination gas control integrating an internal (within

the valve) gas bleed line shall be permitted to discharge its

bleed line back into the valve body, provided that the

construction of the combination gas control is such that when

it is in the closed position, a damaged diaphragm will not allow

gas to flow through the bleed line to the main burner.

(3) At locations where a point of discharge may be submerged

during floods, a special antiflood-type breather vent fitting

shall also be installed at the point of discharge, or the line

shall be extended above the height of the expected flood

waters.


9.1.19 (3)

In the case of vent lines leading outdoors, means shall be

employed to prevent water from entering this piping and also

to prevent blockage of vents by insects or foreign matter.

9.1.20 (2)

In the case of bleed lines leading outdoors, means shall be

employed to prevent water from entering this piping and also

to prevent blockage of vents by insects or foreign matter.

NFPA 54 – Points of Discharge

Anti-flooding device

An anti- flooding device protects gas train components from damage from water

and debris that may cause corrosion of internal parts, operational failure, gas

leakage, or elevated outlet pressure. These devices are a normally open assembly.

When submerged an internal float will rise with the water and seal the vent line

closed. The process reverses as water recedes allowing the float to drop and re-

opening the valve.


(i) The point of discharge from a vent line, bleed line, gas-

pressure relief line, or vent valve line that is piped by the

installer to the outdoors shall have clearances as determined

by the authority having jurisdiction, and the point of discharge

shall extend above the boiler and adjacent structures to

prevent gaseous discharge from being drawn into combustion

air intakes, ventilating systems, mechanical air intakes, or

windows of the boiler room or of an adjacent building.

CF-190 – Clearances for Points of Discharge

(4) A bleed line or a vent line shall be permitted to discharge

into a continuous pilot, provided that the line is not

manifolded and the point of discharge uses a burner tip.

(5) A bleed line or a vent line shall not discharge

into a positive-pressure-type combustion chamber.


9.1.19 (5) In the case of vents entering the combustion chamber,

the vent shall be located so the escaping gas will re readily ignited

by the pilot and the heat liberated thereby will not adversely affect

the normal operation of the safety shutoff system. The terminus of

the vent shall be securely held in a fixed position relative to the

pilot. For manufactured gas, the need for a flame arrester in the

vent piping shall be determined.

9.1.20 (4) In the case of bleed lines entering the combustion

chamber, the bleed line shall be located so the bleed gas will be

readily ignited by the pilot and the heat liberated thereby will not

adversely affect the normal operation of the safety shutoff system.

The terminus of the bleed line shall be securely held in a fixed

position relative to the pilot. For manufactured gas, the need for a

flame arrester in the bleed line piping shall be determined.


9.1.19 (6) A vent line(s) from an appliance gas pressure

regulator and a bleed line(s) from a diaphragm-type valve

shall not be connected to a common manifold terminating in a

combustion chamber. Vent lines shall not terminate in

positive-pressure type combustion chambers.

9.1.20 (5) A bleed line(s) from a diaphragm-type valve and a

vent line(s) from an appliance pressure regulator shall not be

connected to a common manifold terminating in a combustion

chamber. Bleed lines shall not terminate in positive-pressure

type combustion chambers.


(1) Burner tips, when required by CF-190(h)(4), shall be made

of metal having a melting point greater than 1,450°F

(788°C), and its length shall extend from the location as

defined in CF-190(j)(3) to the outer wall of the combustion

chamber.

(2) The installer shall demonstrate compliance to CF-190(j)(1)

with the documentation accompanying the boiler.

(3) Burner tips shall be located so that the escaping gas will

be readily ignited by the pilot flame, and the burner tips shall

be securely held so that the ports are in a fixed position in

relation to the pilot flame.

CF-190 – Burner Tips

(k) Feedback Lines for Fuel Train Components. Feedback lines

shall be piped according to the manufacturer’s instructions.

CF-190 – Feedback Lines

(l) All materials used for bleed lines, vent lines, vent valve

lines, feedback lines, and gas-pressure relief lines shall

possess suitable strength and durability for the environmental

stresses to which the material will be exposed during normal

operation. The materials shall be listed for the intended

purpose in accordance with a nationally recognized standard

acceptable to the authority having jurisdiction. In the absence

of such a standard, NFPA 54, National Fuel Gas Code, shall be

used.

CF-190 – Bleed, Vent, and Relief Lines

4.9.1 The discharge from atmospheric vents shall be located

away from any occupied areas, sources of ignition, combustion

air intakes, building ventilation systems, or the windows of the

boiler or HRSG room or adjacent buildings and shall be extended

above the boiler or HRSG and adjacent structure so that gaseous

discharge does not present a hazard.

4.9.2 Vent line sizes and vent valve port diameters shall not be

less than the values shown in Table 4.9.2

4.9.3.1 Vents of systems operating at different pressure levels

shall not be manifolded.

4.9.3.2 Vents from systems served from different pressure

reducing stations shall not be manifolded.

NFPA 85 – Bleed, Vent, and Relief Lines

4.9.3.3 Vent Systems of different boilers or HRSG’s shall not be

manifolded.

4.9.3.4 Vents of systems using different fuel sources shall not be

manifolded.

4.9.3.5 Headers vents shall be permitted to be manifolded with

other header vents only where they are operated and tripped in

parallel.

4.9.3.6 Burner vents shall be permitted to be manifolded together

only with other burner vents.

4.9.3.7 Igniter vents shall be permitted to be manifolded together

only with other igniter vents.

4.9.3.8 Lance vents shall be permitted to be manifolded together

only with other lance vents.

NFPA 85 – Bleed, Vent, and Relief Lines

Questions


Modular Boilers Only... · 2018-11-12 · ASME Section IV and CSD-1 Hot Water Heating Module...

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Transcript of Modular Boilers Only... · 2018-11-12 · ASME Section IV and CSD-1 Hot Water Heating Module...