P01 BEI Report PAL VA National Contract Testing July 2023-r1.pdf

19HEFE Office of Healthcare Engineering Boiler Safety Device Testing Review July 18-20, 2023

BEI Reviewers:

Chase O’Mary, BEI Engineer

David Burch, BEI Engineer

VHA Healthcare Environment & Facilities Program Office of Healthcare Engineering (10NA5E) Boiler Efficiency Institute LLC.

PALO ALTO, CA VA MEDICAL CENTER

Review Date: July 18-20, 2023

Boiler Safety Device

Testing Review

Contents

1. Introduction

2. Safety Device Awareness

3. General Comments and Recommendations

4. Safety Device Testing Results for Plant Support Equipment

4.1 Condensate Storage Tank High Water Alarm

4.2 Condensate Storage Tank Low Water Alarm

4.3 Feedwater Deaerator High Water Alarm

4.4 Feedwater Deaerator Low Water Alarm

4.5 Feedwater Deaerator Overflow System

4.6 Feedwater Deaerator Steam Safety Valve

4.7 Safety Valve following a Steam Pressure Reducing Valve Station (PRV)

4.8 Boiler Plant Building Combustible and Carbon Monoxide Monitor

4.9 Provisions for Admission of Combustion Air into the Boiler Plant Building

4.10 Propane Pilot Backup System

4.11 Oil Liquid Relief Valve – Pump Set

5. Safety Device Testing Results for Boiler No. 2

5.1 Boiler Water Level Control

5.1.1 Low Water Cutoff (LWCO)

5.1.2 Auxiliary Low Water Cutoff (ALWCO)

5.1.3 Low Water Alarm (LWA)

5.1.4 High Water Alarm (HWA)

5.2 Pressure Containment

5.2.1 Steam Safety Valves (SV)

5.2.2 Operating Steam Pressure Limit Switch (Recycling)

5.2.3 High Steam Pressure Limit Switch (Non-recycling)

5.3 Fuel Train Safety Devices – Natural Gas Section

5.3.1 Low Pressure Gas Fuel Cutoff Switch (LPFCS)

5.3.2 High Pressure Gas Fuel Cutoff Switch (HPFCS)

5.3.3 Automatic Gas Fuel Shutoff Valves – Leak Test

5.3.4 Gas Train Solenoid Vent Valve – Operation and Leak Test

5.3.5 Automatic Gas Fuel Shutoff Valves – Proof of Closure (POC)

5.3.6 Automatic Pilot Gas Shutoff Valves – Leak Test

5.3.7 Pilot Gas Train Solenoid Vent Valve – Operation and Leak Test

5.4 Fuel Train Safety Devices – #2 Oil Section

vhaglasubhan Text Box For 4.12, 4.13, and 4.14 see page 12

5.4.1 Low Pressure Oil Fuel Cutoff Switch (LPFCS)

5.4.2 High Pressure Oil Fuel Cutoff Switch (HPFCS)

5.4.3 Low Oil Atomizing Media Pressure Switch (LAMPS)

5.4.4 Alternative Switches for Atomizing Service:

5.4.5 Automatic Oil Fuel Shutoff Valves – Leak Test

5.4.6 Automatic Oil Fuel Shutoff Valves – Proof of Closure (POC)

5.4.7 Burner Position Switch

5.5 Burner and Air Train Safety Devices

5.5.1 Flame Scanner – Test for Flame Failure Response Time (FFRT)

5.5.2 UV Scanner Not Sensing Ignition Spark

5.5.3 Igniter Timing – Pilot Trial for Ignition (PTFI)

5.5.4 Main Flame Trial for Ignition Timing (MTFI)

5.5.5 Pre-purge and Post-purge Timer

5.5.6 Low-Fire Proving Switches

5.5.7 Forced Draft Damper Wide-Open Pre-Purge Proving Switch

5.5.8 Combustion Air Pressure Switch

5.5.9 Pre-Purge Airflow Proving Switch

5.5.10 Forced Draft Motor Interlock

5.5.11 Minimum Pilot Flame Test and Low Pilot Gas Pressure Switch

5.5.12 Low Flue Gas Oxygen Alarm and Cutout

5.5.13 Liquid Relief Valve on Economizer

5.5.14 Flue Gas Recirculation Interlock

5.5.15 Boiler Outlet (Stack) Damper Interlock

5.5.16 Furnace Pressure Switch

6. Plant Reliability

1. Introduction

This report details the results of the steam generation system safety device testing conducted at

Palo Alto, CA VAMC in VISN 21. Under contract with HEFP/ 19HEFE, the BEI team evaluated the major boiler plant safety devices serving the entire plant and those safety devices serving boiler 2 at the facility. The references for the testing include:

• VHA Boiler Plant Safety Device Testing Manual, Seventh Edition

• VHA Directive 1810 Boiler Plant Operations

The report first lists safety devices serving the whole plant and then safety devices serving the boilers. Reported are: results of each safety device tested, comments and recommendations. See tables in section 3 for a summary of safety device testing results.

2. Safety Device Awareness

The Veterans Health Administration regards boiler safety as so important that they require as a matter of policy that Medical Center Directors be notified if a boiler safety device is found to be non-functional. Each safety device installed on the boilers or serving the whole boiler plant mitigates risk or is part of a system to mitigate risk. Safety devices and systems must be properly installed, properly calibrated, properly tested and maintained to be effective in mitigating risk. Boiler plants inherently have the potential for catastrophic failure. When a device is found to be inadequate, prompt repair is essential to ensure a safe working environment.

3. General Comments and Recommendations

• VA Policy Violations (Directive 1810, Master Spec, Design Manual etc) o Per VA design alert all cast iron fittings on high pressure (>15 psig) steam lines must be identified and a plan for replacement implemented.

o All safety valves noted in the report are cast iron material. Cast iron valves on boilers must be replaced with cast steel upon failure. All cast iron safety valves exposed to steam pressure of 15 psig or higher must be replaced with cast steel.

o PRV station serving DA tank is a 1/3- 2/3 parallel setup. Safety valve is only sized to relief larger PRV but not both. Per VA spec relief valve must be sized to relief combined flow capacity of both PRVs.

o Electric current monitoring relays for boiler fans are located in a high voltage cabinet exposed to 480VAC. These relays must be located separate from exposed high voltage in their own enclosure.

o VA master specification requires a manual reset automatic shutoff valve in the propane line serving the boiler plant. These valves must be wired into the Estop circuit to close upon activation. Currently there is no valve installed.

o The boilers are equipped with a non compliant safety burner management system.

PLC system has adjustable/configurable parameters and programmable logic. VA requires BMS systems to burned in (unadjustable) after commissioning parameters. Refer to VA spec 230911 for proper system.

o Zeeco burner is not set up to use a pilot flame ignition system when firing natural gas. System uses a high intensity spark system. VA spec requires a pilot flame ignition system on all burners.

• This report contains safety device failures the details of which are contained in this report. If the boiler is to remain in operation, then Interim Safety Measures must be implemented and tracked per Directive 1810.

Safety Device Testing Summary

Total Number of Devices

Compliant as Found

Total Number of Devices Failed but Repaired

Total Number of Devices Failed and Not Repaired

Total As Found Compliance 30%

Final Compliance 30%

Plant Device Summary

Device Result

4.1 Condensate Storage Tank High Water Alarm Fail

4.2 Condensate Storage Tank Low Water Alarm Fail

4.3 Feedwater Deaerator High Water Alarm Fail

4.4 Feedwater Deaerator Low Water Alarm Fail

4.5 Feedwater Deaerator Overflow System Fail

4.6 Feedwater Deaerator Steam Safety Valve Pass

4.7 Safety Valve following a Steam Pressure Reducing Valve Station (PRV)-DA Fail

4.8 Boiler Plant Building Combustible and Carbon Monoxide Monitor Fail

4.9 Provisions for Admission of Combustion Air into the Boiler Plant Building Pass

4.10 Propane Pilot Backup System Pass

4.11 Oil Pump Liquid Relief Valve Fail

4.12 Control Air Pressure Alarm Fail

4.13 Emergency Stop Panic Button Fail

4.14 High Fuel Gas Pressure Cutout on Main Gas Line Fail

Boiler No. 2 Device Summary

Device Status

5.1.1. Low Water Cutoff (LWCO) Pass

5.1.2. Auxiliary Low Water Cutoff (ALWCO) Pass

5.1.3. Low Water Alarm (LWA) Pass

5.1.4. High Water Alarm (HWA) Pass

5.2.1. Steam Safety Valves (SV) Fail

5.2.2. High Steam Pressure Limit Switch Fail

5.2.3. High High Steam Pressure Limit Switch Pass

5.3.1. Low Pressure Gas Fuel Cutoff Switch (LPFCS) Fail

5.3.2. High Pressure Gas Fuel Cutoff Switch (HPFCS) Fail

5.3.3. Automatic Gas Fuel Shutoff Valves – Leak Test Pass

5.3.4. Gas Train Solenoid Vent Valve – Operation and Leak Test Fail

5.3.5. Automatic Gas Fuel Shutoff Valves – Proof of Closure (POC) Fail

5.3.6. Automatic Pilot Gas Shutoff Valves – Leak Test Pass

5.3.7. Pilot Gas Train Solenoid Vent Valve – Operation and Leak Test Fail

5.4.1. Low Pressure Oil Fuel Cutoff Switch (LPFCS) Fail

5.4.2. High Pressure Oil Fuel Cutoff Switch (HPFCS) Fail

5.4.3. Low Oil Atomizing Media Pressure Switch (LAMPS) Fail

5.4.4. Alternative Switches for Atomizing Service (SLAMPS)/(LDAMPS) Fail

5.4.5. Automatic Oil Fuel Shutoff Valves - Leak Test Pass

5.4.6. Automatic Oil Fuel Shutoff Valves - Proof of Closure (POC_ Fail

5.4.7. Burner Position Switch Pass

5.5. Burner Management System Programmer Fail

5.5.1. Flame Scanner – Test for Flame Failure Response Time (FFRT) Pass

5.5.2. UV Scanner Not Sensing Ignition Spark Pass

5.5.3. Igniter Timing – Pilot Trial for Ignition (PTFI) Fail

5.5.4. Main Flame Trial for Ignition Timing (MTFI) Fail

5.5.5. Pre-purge and Post-purge Timer Fail

5.5.6. Low-Fire Proving Switches Fail

5.5.7. Forced Draft Damper Wide-Open Pre-Purge Proving Switch Fail

5.5.8. Combustion Air Pressure Switch Fail

5.5.9. Pre-Purge Airflow Proving Switch Fail

5.5.10. Forced Draft Motor Interlock Not tested

5.5.11. Minimum Pilot Flame Test and Low Pilot Gas Pressure Switch Fail

5.5.12 Low Flue Gas Oxygen Alarm and Cutout Fail

5.5.13 Liquid Relief Valve on Economizer Not tested

5.5.14. Flue Gas Recirculation Damper Interlock N/A

5.5.15. Outlet Damper Interlock N/A

5.5.16. Furnace Pressure Switch N/A

4. Safety Device Testing Results for Plant Support Equipment

4.1 Condensate Storage Tank High Water Alarm

Purpose: High water level may be an indication of condensate transfer pump failure that could lead to low water condition in the feedwater deaerator and in the boilers. There may be a failure of make-up water controls.

Recommended set point: 4 inches below overflow level and 2/3 of tank height.

Potential hazards due to failure of high water alarm: Feedwater deaerator running dry and, consequently, boiler feed pumps running dry will cause overheating and damage to pumps and potential for plant shut down. Failure of make-up water controls (in open position) could lead to significant cost from waste of water and condensate from the tank overflow if this occurs over a long time period.

Recommended type of device: Conductivity probe type switch. Float type switches have high failure rate in this application where they are exposed to flash steam that causes seals to harden and prevent float movement.

VA Master Specification section: http://www.cfm.va.gov/TIL/spec/235011.doc

VA Standard Detail: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-05.pdf

Failure rate of float types: 48% (BEI study of VA boiler plants).

Make and Model: Reliance probe

Did it function properly: No

Comments: Fail installation- Valves that can isolate column are not lockable only open. Device activated at 2/3 of tank height. Alarm functioned correctly. Modify valve to be lockable only open.

4.2 Condensate Storage Tank Low Water Alarm

Purpose: Low water level is an indication of make-up water failure or condensate return failure. Immediate action must be taken to avoid plant shutdown.

Recommended set point: Approx. 1/3 of tank height.

Potential hazards due to failure of low water alarm: Low water in condensate storage tank can cause overheating and damage to condensate transfer pumps. Likely to “starve” feedwater deaerator and boiler feed pumps resulting in boiler feed pumps running dry and damaging pumps and potential for plant shut down

Recommended type of device: Float type or conductivity probe type is acceptable.

VA Master Specification section: http://www.cfm.va.gov/TIL/spec/235011.doc

VA Standard Detail: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-05.pdf

Failure rate of float types: 19% (BEI study of VA boiler plants).

Make and Model: Reliance probe

Did it function properly: No

Comments: Fail Installation- Valves that can isolate column are not lockable only in open position. Alarm activated above 1/3 of tank height. Alarm audible. Make valves lockable only open.

4.3 Feedwater Deaerator High Water Alarm

Purpose: Warns of high water level before overflow occurs. High water may be due to failure of inlet water control valve system.

http://www.cfm.va.gov/TIL/spec/235011.doc http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-05.pdf http://www.cfm.va.gov/TIL/spec/235011.doc http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-05.pdf

Recommended set point: 4 inches below overflow level and 2/3 of tank height. Potential hazards due to failure of high water alarm: Excess water level can cause dangerous water hammer in the DA as the water level encroaches into the steam space.

Recommended type of device: Conductivity probe type switch. Float type switches have high failure rate in this application where they are exposed to steam that causes seals to harden and prevent float movement.

VA Master Specification section: http://www.cfm.va.gov/TIL/spec/235011.doc

VA Standard Detail: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-06.pdf

Failure rate of float types: 59% (BEI study of VA boiler plants).

Make and Model: Reliance Probe

Did it function properly: No

Comments: Fail installation- Valves that can isolate column are not lockable only open. Device activated below 2/3 of tank height. Alarm audible. Make isolation valves lockable only in open position.

4.4 Feedwater Deaerator Low Water Alarm

Purpose: Warns of low water level before water level drops too low to adequately supply the boiler feed pumps.

Recommended set point: Approx. 1/3 of tank height..

Potential hazards due to failure of low water alarm: Damage to boiler feed pumps if they run dry and possible plant shut down.

Recommended type of device: Float type or conductivity probe type is acceptable.

VA Master Specification section: http://www.cfm.va.gov/TIL/spec/235011.doc

VA Standard Detail: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-06.pdf

Failure rate of float types: 25% (BEI study of VA boiler plants.)

Make and Model: Reliance probe

Did it function properly: No

Comments: Fail Installation- Valves that can isolate column are not lockable only in open position. Alarm activated above 1/3 of tank height. Alarm audible. Make isolation valves lockable only in open position.

4.5 Feedwater Deaerator Overflow System

Purpose: Drain excessive water level.

Recommended set point: Determined by deaerator manufacturer to maximize water storage and avoid water hammer from excessive water level impinging on the deaerator steam space.

This level should be at least 4” below the top of the tank.

Potential hazards from failure of overflow device: Water hammer and rupture of deaerator, opening of safety valve. Potential for scalding hot water flowing down into the boiler room from ruptured deaerator or from safety valve.

Recommended type of device: Independent control system with conductivity probe water level sensor and butterfly type overflow valve. Float type overflow valves have very high failure rate and are no longer specified.

VA Master Specification section: http://www.cfm.va.gov/TIL/spec/235011.doc

VA Standard Detail: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-06.pdf

Failure rate of float type overflow valves: 61% (BEI study of VA boiler plants.)

Make and Model: Warrick probe http://www.cfm.va.gov/TIL/spec/235011.doc http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-06.pdf http://www.cfm.va.gov/TIL/spec/235011.doc http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-06.pdf http://www.cfm.va.gov/TIL/spec/235011.doc http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-06.pdf

Did it function properly: No

Comments: Fail installation – Valve that can isolate safety must be made lockable only in open position.

Overflow functioned correctly.

4.6 Feedwater Deaerator Steam Safety Valve

Purpose: Serves as “sentinel” valve mounted on deaerator warning of excessive steam pressure. In combination with the safety valves on the steam pressure reducing station serving the deaerator, it protects the deaerator pressure vessel from overpressure.

Recommended set point and capacity: 10 psig. Capacity should be 500-1000 lb/hr. Normal operating pressure of deaerator is 5 psig. Pressure vessel design pressure is usually 30 psig.

The safety valve on the steam pressure reducing station serving the deaerator should be set at

15 psig.

Potential hazards from failure of safety valve: Rupture of deaerator pressure vessel because of overpressure. Scalding hot water and steam may fill a large portion of the boiler plant.

Recommended type of device: ASME and National Board-rated steam safety valve.

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/232111.docx

VA Standard Details: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-02.pdf

Failure rate of deaerator safety valves: 82% (BEI study of VA boiler plants.)

Make and Model: Kunkle 10 psi

Setpoint: 10 psig 8297 lb/hr

DA maximum allowable working pressure (MAWP): 30 psig

DA operating pressure: 5 psig

Date of non-destructive test of DA tank welds: NDT 2020

Did it function properly: Yes

Lift Pressure: 9.5 psig

Comments: Pass- Safety valve lifted at 9.5 psig and reseated at 8 psig.

4.7 Safety Valve following a Steam Pressure Reducing Valve Station (PRV) Purpose: Protect downstream steam systems from overpressure due to failure of PRV.

Recommended set point and capacity: 10 - 15 psi above set point of pressure reducing valve. The flow capacity must exceed the maximum capacity of the wide open PRV, or the manual bypass around the PRV, whichever is greater. If there are two PRVs in parallel, the safety valve capacity should be based on the largest PRV, wide open.

Potential hazards from failure of safety valve: Rupture of pressure vessel or accessory connected to the steam system. Potential of filling space at location of ruptured pressure vessel with steam and scalding hot water.

Recommended type of device: ASME and National Board-rated steam safety valve.

VA Master Specification section: http://www.cfm.va.gov/cfm/TIL/spec/232111.docx

And http://www.cfm.va.gov/cfm/TIL/spec/235011.doc

VA Standard Detail:http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-02.pdf http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-03.pdf

Failure rate of safety valves following PRVs: 56% (BEI study of VA boiler plants.)

Make and Model: Kunkle 15 psig (6857 Lb.hr)

Serving the Deaerator.

Setpoint: 15 psig http://www.cfm.va.gov/cfm/TIL/spec/232111.docx http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-02.pdf http://www.cfm.va.gov/cfm/TIL/spec/232111.docx http://www.cfm.va.gov/cfm/TIL/spec/235011.doc http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-02.pdf http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-03.pdf

Upstream Pressure: 90 psig

Downstream Pressure: 5 psig

Safety Capacity: 6857 lbs/hr

Did it function properly: Yes

Lift Pressure: 15

Reseat Pressure: 14

Comments: Fail installation (policy Violation)- System as installed does not meet VA spec for type and configuration. See VA spec for proper setup. Safety valve must be of cast steel construction and be sized to relieve the full flow capacity of both parallel PRV stations combined.

4.8 Boiler Plant Building Combustible and Carbon Monoxide Monitor Purpose: Warns of presence of combustibles or carbon monoxide in the building. This can be the result of flue gas leaks in the boiler setting or breeching and improper burner adjustments.

Recommended setpoints: 50 ppm carbon monoxide and 10% of the lower explosive limit.

Hazard from failure of the monitor: Carbon monoxide may cause death of personnel.

Combustible gas may explode.

Recommended type of monitoring system: Multiple sensors located near potential sources and in locations where personnel are normally working. Industrial-type automatic system.

Recommend 2 combustible sensors high in the plant, CO monitors close to the boilers near potential flue gas leak points and in personnel rooms (particularly those with exhaust systems).

VA Master Specification section: http://www.cfm.va.gov/cfm/TIL/spec/230911.docx

VA Standard Detail: None.

Failure rate of monitoring system: 93%. (BEI study of VA boiler plants. In most cases, the monitoring system was not present.)

Make and Model: Sensidyne

Setpoint: 50 ppm CO, 10%LEL CH4

Did it function properly: No

Comments: Fail Installation (Policy Violation)-There are 2 combustible sensors and 3 Carbon monoxide sensors. There is no mezzanine and DA area protection. Floor level protection only. Sensors are out of calibration. No test gas for either system to function test.

4.9 Provisions for Admission of Combustion Air into the Boiler Plant

Building Purpose: Air from outside the building is necessary for proper combustion in the boilers.

There must be provisions for supplying this air.

Recommended setpoint: There must be sufficient outside air admitted to the building so that the negative pressure in the building is negligible. “Negligible” can be defined as -0.05 inches water column.

Hazards from failure to provide the outside air: Combustion in the furnace can become fuel-rich due to lack of sufficient combustion air. Boiler steam output capacity can be reduced due to reduced burner capacity from lack of adequate combustion air. Fuel-rich firing can be dangerous if combustion air is increased suddenly. An explosion can occur that damages equipment and injure personnel. Cold outside air can be drawn down the stack of non-operating boilers and freeze the water in the boilers. This can cause serious damage to boilers.

http://www.cfm.va.gov/cfm/TIL/spec/230911.docx

Recommended type of outside air admission system: The preferred system in cold climates is a heating and ventilating unit that brings in 100% outside air and heats it to at least 60 degrees F.

This should be interlocked with the burners so that they can’t fire unless the H&V unit is running. In milder climates, louvers in the building wall are acceptable. They should be interlocked with the burner controls so that they are proved open for the burners to fire.

VA Master Specification section: http://www.cfm.va.gov/cfm/TIL/spec/237300.doc

VA Standard Detail: None.

Type of combustion air make-up system: Makeup airhandler plus fixed opening

Make and model: N/A

Did it function properly: Yes

Comments: Pass -There is sufficient fixed opening.

4.10 Propane Pilot Backup System

Purpose: Alternate pilot burner fuel for igniting main oil burner when natural gas is not available for the pilot burner (igniter).

Recommended setpoint: Propane header set at 5 psig. (Lowest practical pressure.)

Potential hazards from failure of propane system: Inability to ignite oil burners when natural gas is not available for the pilot burners. Natural gas supply could be interrupted because of distribution system failure.

Recommended type of system: Portable or Permanent tanks located outside the building connected to pilot burners with permanent piping.

VA Master Specification sections: 23 21 11 (old 15339), 23 52 39 (old 15622), 23 52 33 (old

15623), 23 52 33 (old 15624). www.va.gov/facmgt/standard/

VA Standard Details: SD235239-03.pdf. www.va.gov/facmgt/standard/

Failure rate of propane system: 30% (BEI study of VA boiler plants.)

Comments: Pass- System functioned properly.

4.11 Oil Liquid Relief Valve – Pump Set

Purpose: Protect oil pumping system from overpressure. Overpressure may be due to failure of back pressure regulator (pressure control valve) or starting the pump with the discharge valves closed.

Recommended setpoint: Approx. 10 psi above setpoint of back pressure regulator.

Potential hazards from failure of oil relief valve: Rupture of oil system apparatus, such as pressure switches or damage to pumps. Excess oil burner pressure resulting in dangerous fuel-rich flame that could cause damaging furnace “puffs” or explosion.

Recommended type of device: Liquid relief valve sized for maximum pump capacity and designed to shut tight.

VA Master Specification section: 23 50 11 (old 15625). www.va.gov/facmgt/standard/

VA Standard Detail: SD235239-04.pdf. www.va.gov/facmgt/standard/

Failure rate of oil relief valves: 40% (BEI study of VA boiler plants.)

Make and Model: CASH

Setpoint: less than 110 psig

Pump discharge pressure: 100 psig

Did it function properly: No http://www.cfm.va.gov/cfm/TIL/spec/237300.doc

Comments: Fail Setpoint – Valves are always flowing when system is in operation. Valves are open at regulated pressure. Adjust setpoint or replace valves to open at proper setpoint.

4.12 Control Air Pressure Alarm

Make and Model: Ashcroft 0-100 psig

Setpoint: 45 psig

Minimum Required Pressure: 60 psig

Did it function properly: No

Comments: Fail setpoint- System trips boiler offline, but setpoint is below minimum actuation pressure of gas valves. Adjust setpoint to be above the minimum actuation pressure.

4.13 Emergency Stop Panic Button

Type: Glass break switch type.

Did it function properly: Yes

Comments: Fail installation (policy Violation)-Switches in control room and on main panel are not protected from accidental activation. System functions properly, but propane line is not equipped with an automatic shutoff valve.

4.14 High Fuel Gas Pressure Alarm on Main Gas Line

Type: N/A

Regulated Gas Pressure: N/A

Setpoint: N/A psig

Did it function properly: See comments

Comments: Fail installation (policy violation)- No high fuel gas pressure alarm on main gas line is installed. Install to comply with VA requirements.

5. Safety Device Testing Results for Boiler No. 2

Table 6.1 Description of Boiler and Burner

Boiler # 2

Manufacturer: Nebraska

Model: NS-C/S-61

Serial #: National Board No.: 03140

Typical Operating Pressure: 90 psig

Date of Manufacture: 1994

Design Pressure/Capacity: 200 psig / 35,000 lb/hr

Burner:

Manufacturer: Zeeco (2016)

Fuels: Natural Gas and

No. 2 Fuel Oil

5.1 Boiler Water Level Control

5.1.1 Low Water Cutoff (LWCO)

Purpose: Primary control to shutdown burner if boiler water level is too low. This could result from failure of feedwater pump or boiler water level control system.

Recommended setpoint: As required by boiler manufacturer and at least 1”below the low water alarm. Water level in the gage glass must be clearly visible from the operating floor at the set point.

Potential hazard from failure of LWCO: Water level in boiler may go sufficiently low to cause boiler explosion if the auxiliary low water cutoff (ALWCO) also fails. This double failure has been witnessed in a VA plant. Low boiler water is a major cause of boiler accidents.

Recommended type of cutoff device: The LWCO and ALWCO should be of different types so that both are not subject to the same mode of failure.

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Standard Details: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-01.pdf

Failure rate of LWCO: 14% (BEI study of VA boiler plants.)

Make and Model: Warrick Probe

Did it function properly: Yes

Comments: Pass- Probe cutout activated with 2 inches of water in the sight glass. Boiler shutdown and locked out properly.

5.1.2 Auxiliary Low Water Cutoff (ALWCO)

Purpose: Secondary control to shutdown burner if boiler water level is too low and the primary low water cutoff (LWCO) fails to operate.

Recommended setpoint: As required by boiler manufacturer. Located at least 1” below the low water cutoff (LWCO) setpoint. Water must be visible in gage glass at the setpoint.

Potential hazard from failure of ALWCO: Water level in boiler goes sufficiently low to cause boiler explosion.

Recommended type of cutoff device: The LWCO and ALWCO should be of different types so that both are not subject to the same mode of failure.

http://www.cfm.va.gov/cfm/TIL/spec/235239.docx http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-01.pdf

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Standard Details: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-01.pdf

Failure rate of ALWCO: 32% (BEI study of VA boiler plants.)

Make and Model: Reliance Float

Did it function properly: Yes

Comments: Pass- Cutout activated with approx. 1 in of water in the sight glass. Boiler shut down and locked out properly.

5.1.3 Low Water Alarm (LWA)

Purpose: Provides advance warning of low water condition in boiler allowing personnel to correct situation before low water cutoff occurs.

Recommended setpoint: At least 1” above the primary low water cutoff (LWCO).

Potential hazard from failure of LWA: Unplanned burner shut down due to operation of low water cutoffs. Boiler explosion from low water if the low water cutoffs do not operate properly.

Recommended type of LWA device: The LWA provides a visual and audible signal but does not shut down the burner.

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Standard Details: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-01.pdf

Failure rate of LWA device: 11% (BEI study of VA boiler plants.)

Make and Model: Warrick Probe

Did it function properly: Yes.

Comments: Pass – LWA activates at the 6 in -inch water level in the sight glass. Alarm audible and visually indicated.

5.1.4 High Water Alarm (HWA)

Purpose: Provides warning of high water level in boiler.

Recommended setpoint: As recommended by boiler manufacturer. Water level in the gage glass must be clearly visible from the operating floor at the set point.

Potential hazard from failure of HWA: Water level could increase sufficiently to cause tremendous carryover of liquid water with the boiler steam into the steam piping resulting in dangerous water hammer. Potential for piping rupture releasing steam into the boiler room.

Recommended type of HWA: The HWA provides a visual and audible signal but does not shut down the burner.

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Standard Details: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-01.pdf

Failure rate of HWA device: 7% (BEI study of VA boiler plants.)

Make and Model: Warrick Probe

Did it function properly: Yes

Comments: Pass- Activated at 1 inch water level from top of sight glass. Alarm is audible throughout plant.

5.2 Pressure Containment

5.2.1 Steam Safety Valves (SV)

Purpose: Protects boiler pressure vessel from overpressure. Multiple valves are required on all except very small boilers as allowed by ASME Code. Recommended setpoint: SV with lowest http://www.cfm.va.gov/cfm/TIL/spec/235239.docx http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-01.pdf http://www.cfm.va.gov/cfm/TIL/spec/235239.docx http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-01.pdf set point should be 10 psig above set point of non-recycle high pressure cutout. This should be approximately 30 psig above normal operating pressure of steam header. A minimum of 5 psig should be allowed between set points of multiple safety valves. All setpoints must be below the design pressure of the boiler.

Potential hazard from failure of SV: Boiler pressure vessel explosion due to overpressure releasing large quantities of steam and hot water into the boiler plant. Severe damage to the boiler and to the plant.

Recommended type of SV: ASME/NB certified steam safety valves rated for power boiler

(ASME Section I) service.

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Standard Details: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-02.pdf

Failure rate of boiler SV: 33% (BEI study of VA boiler plants.)

Make and Model: Kunkle (Cast iron)

Setpoint: SV#1—125 psig 18447 lbs/hr) SV# 2-- 130 psig (24,152 lbs/hr)

Did it function properly: No

Comments: Fail (Policy)-Installation -SV1– 122 psig lift and reseat at 117 psig. SV2 lifted at

128 and reseated at 122 psig. Max pressure 128 psig. Vents not adequate. Room fills with substantial amounts of steam. Valves are cast iron construction. Valves must be cast steel per VA master specification and design alert.

5.2.2 High Steam Pressure Limit Switch

Purpose: Shuts down burner if boiler steam pressure exceeds setpoint. Allows burner to automatically restart when pressure decreases sufficiently. Operates mainly during periods when steam demands are less than the steam produced at the lowest firing rate of the burner.

Recommended setpoint: Approximately 10 psig above normal steam header pressure.

Potential hazard from failure of operating limit switch: Boiler explosion from overpressure if there are also failures of the non-recycling pressure switch and the boiler safety valves. Excess pressure on steam distribution system that could cause pressure reducing valves in the system to fail. This has the potential for over-pressuring steam systems downstream from the pressure reducing stations if the pressure reducing station safety valves fail.

Recommended type of pressure switch: Switch must be UL and FM approved for this service.

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Standard Details: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-01.pdf

Failure rate of operating limit switch: 29% (BEI study of VA boiler plants.)

Make and Model: Asco 0-200 psi range

Setpoint: unknown psig

Did it function properly: No

Comments: Fail setpoint- Switch never activated. Reset or replace switch. Normal steam pressure is 90 psig. SV 1 is set at 125 psig.

5.2.3 High High Steam Pressure Limit Switch

Purpose: Causes shut down of burner if boiler steam pressure exceeds setpoint. Does not allow burner to automatically restart when pressure decreases.

Recommended setpoint: Approximately 5 psig above set point of high pressure switch. 5 psig below lowest set point of boiler safety valves.

Potential hazard from failure of operating limit switch: Boiler explosion from overpressure if http://www.cfm.va.gov/cfm/TIL/spec/235239.docx http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD232111-02.pdf there are also failures of the boiler safety valves. Excess pressure on steam distribution system that could cause pressure reducing valves in the system to fail. This has the potential for over-pressuring steam systems downstream from the pressure reducing stations if the pressure reducing station safety valves fail.

Recommended type of pressure switch: Switch must be UL and FM approved for this service.

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Standard Details: http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-01.pdf

Failure rate of non-recycling limit switch: 36% (BEI study of VA boiler plants.)

Make and Model: Asco 0-200 psig

Setpoint: 104 psig

Comments: Pass- High-High cutout activated at 104 psig. Logic good..

5.3 Fuel Train Safety Devices – Natural Gas Section

5.3.1 Low Pressure Gas Fuel Cutoff Switch (LPFCS)

Purpose: Shuts down the burner if the fuel pressure drops to the setpoint. This can be the result of a pressure regulator failure or clogged fuel filter.

Recommended setpoint: Per burner manufacturer’s instructions, which should be within 15-

20% of the normal operating pressure.

Potential hazard from failure of the cutoff switch: As an example, a pressure regulator malfunction that allows the fuel pressure to drop and then allows the fuel pressure to increase could result in a furnace explosion from the excess air present in the furnace and the sudden increase of fuel into the furnace.

Recommended type of pressure switch: UL and FM approved for gas fuel service.

VA Master Specification section: http://www.cfm.va.gov/cfm/TIL/spec/230911.docx

VA Standard Detail:http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-03.pdf

Failure rate of LPFCS: 46% (BEI study of VA boiler plants.)

Make and Model: Ashcroft 0-15 psig

Fuel train operating pressure: 10.5 psig

Setpoint: 5.8 psig

Did it function properly: No

Comments: Fail Installation/Setpoint/logic – There is a snubber in place. Snubbers are no allowed in the VA. Setpoint is too low. Setpoint must be 80% of regulated pressure. There is a 5 second delay between switch activation and boiler shutdown. Delay is not allowed on safety devices.

5.3.2 High Pressure Gas Fuel Cutoff Switch (HPFCS)

Purpose: Shuts down the burner if the fuel pressure rises to the setpoint. This can be the result of a pressure regulator failure.

Recommended setpoint: Per burner manufacturer’s recommendations which should be within

15-20% of the normal operating pressure.

Potential hazard from failure of the cutoff switch: Flame may become very fuel-rich and generate large amounts of carbon monoxide (CO). Change of burner firing rates or shut down may suddenly introduce more combustion air resulting in a damaging furnace “puff” when the excess fuel explodes. A fuel-rich flame is always dangerous.

http://www.cfm.va.gov/cfm/TIL/spec/235239.docx http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-01.pdf http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-03.pdf

Recommended type of pressure switch: UL and FM approved for gas fuel service.

VA Master Specification section: http://www.cfm.va.gov/cfm/TIL/spec/230911.docx

VA Standard Detail:http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-03.pdf

Failure rate of HPFCS: 43% (BEI study of VA boiler plants.)

Make and Model: Ashcroft 0-30 psig

Fuel train operating pressure: 10.5 psig

Setpoint: 13.6 psig

Did it function properly: No

Comments: Fail Installation/Setpoint- Isolation valve is not lockable only in open position.

Switch setpoint is too high. Switch must be set 120% of regulated pressure or lower. Activated at

13.6 psig.

5.3.3 Automatic Gas Fuel Shutoff Valves – Leak Test

Purpose: Open-shut, normally closed valves that operate to start and stop the fuel flow to the main burner. It is essential to have two valves in series with an automatic vent in between and with leak test connections.

Recommended setpoint: Zero seat leakage; also called “bubble-tight”.

Potential hazard from valve seat leakage: Unburned fuel will collect in the furnace when the burner is not operating and may explode when burner is started. Serious damage to boiler and hazard to personnel may result.

Recommended type of fuel valves: UL and FM approved for the fuel service.

VA Master Specification section: http://www.cfm.va.gov/cfm/TIL/spec/230911.docx

VA Standard Detail:http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-03.pdf

Make and Model: Maxon

Comments: Pass- No leaks

5.3.4 Gas Train Solenoid Vent Valve – Operation and Leak Test

Purpose: Open-shut, normally open valve that automatically vents the space between the two automatic fuel shut off valves when the burner is not firing. If the first fuel shut off valve leaks, the leakage will be vented and the second fuel shut off valve will not be pressurized.

Recommended setpoint: Zero leakage.

Potential hazard from valve failure: If vent valve fails closed, it will pressurize the second automatic shut off valve if the first shut off valve is leaking. If the second shut off valve also leaks, the boiler can be filled with fuel which will explode when the burner is started. Leakage of the vent valve seat results in gas loss to the atmosphere with the accompanying cost of the gas.

Recommended type of vent valve: UL approved for the fuel service.

VA Master Specification section: http://www.cfm.va.gov/cfm/TIL/spec/230911.docx

VA Standard Detail:http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-03.pdf

Leak Failure rate of vent valves: 23% (BEI study of VA boiler plants.)

Make and Model: ASCO

Did it function properly: No

Comments: Fail Installation- There are two valves in line that can isolate the vent that are not lockable only open. Modify valves to be lockable only open. No leaks. Valve open when boiler is offline.

http://www.cfm.va.gov/cfm/TIL/spec/230911.docx http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-03.pdf

5.3.5 Automatic Gas Fuel Shutoff Valves – Proof of Closure (POC)

Purpose: Proof that the valves are closed is provided by electrical switches in the valves that sense the position of the valves, open or closed. The switches are in an electrical circuit to the burner management control system. The valves must be “proven” closed before the burner management control allows the ignition sequence to start.

Potential hazard from failure (or absence) of POC switch: A boiler explosion would occur if the pilot burner is ignited with the main fuel valves open and the furnace full of fuel.

Recommended type of POC switch: The switch is furnished with UL and FM approved automatic fuel safety shut off valves.

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Standard Details: None.

Failure rate of POC switches: 42% (BEI study of VA boiler plants.) Typically valves without

POC or with POC but not monitored by burner management systems.

Make and Model: Maxon

Did it function properly: No

Comments: Fail logic- System does not prevent boiler fan from starting when POC switch is open. This could possibly create a dangerous combustible situation in the event the valves are open and are leaking. Boiler fan could start introducing air into a fuel rich mixture. POC switch logic must not allow the boiler fan to start when the POC switch is open.

5.3.6 Automatic Pilot Gas Shutoff Valves – Leak Test

Purpose: Open-shut, normally closed solenoid valves that operate to start and stop the fuel flow to the pilot burner. It is essential to have two valves in series with an automatic vent in between and with leak test connections.

Recommended setpoint: Zero seat leakage; also called “bubble-tight”.

Potential hazard from valve seat leakage: Unburned fuel will collect in the furnace when the burner is not operating and may explode when burner is started. Serious damage to boiler and hazard to personnel may result.

Recommended type of fuel valves: UL and FM approved for the fuel service.

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Standard Detail:http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-03.pdf

Make and Model: Asco

Comments: Pass- NO leaks

5.3.7 Pilot Gas Train Solenoid Vent Valve – Operation and Leak Test

Purpose: Open-shut, normally open solenoid valve that automatically vents the space between the two automatic pilot fuel shut off valves when the pilot burner is not firing. If the first fuel shut off valve leaks, the leakage will be vented and the second fuel shut off valve will not be pressurized.

Recommended setpoint: Zero leakage.

Potential hazard from valve failure: If vent valve fails closed, it will pressurize the second automatic shut off valve if the first shut off valve is leaking. If the second shut off valve also leaks, the boiler can be filled with fuel which will explode when the burner is started. Leakage of the vent valve seat results in gas loss to the atmosphere with the accompanying cost of the gas.

Recommended type of vent valve: UL approved for the fuel service.

http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Master Specification sections: http://www.cfm.va.gov/cfm/TIL/spec/235239.docx

VA Standard Detail:http://www.cfm.va.gov/cfm/til/sDetail/Div23HVACSteam/SD235239-03.pdf

Leak Failure rate of vent valves: Not available.

Make and Model: ASCO

Did it function properly: No

Comments: Fail installation- No leaks, open when boiler is offline. Manual valve downstream of vent valve must be lockable only in open position.

5.4 Fuel Train Safety Devices – #2 Oil Section

5.4.1 Low Pressure Oil Fuel Cutoff Switch (LPFCS)

Purpose: Shuts down the burner if the fuel pressure decreases to the setpoint of the switch. The pressure decrease can be the result of a pressure regulator failure or clogged filter.

Recommended setpoint: Per burner manufacturer’s instructions which should be within 10% of the normal operating pressure.

Potential hazard from failure of the cutoff switch: As an example, a pressure regulator malfunction that allows the fuel pressure to drop and then allows the fuel pressure to increase could result in a furnace explosion from the excess air present in the furnace and the sudden increase of fuel into the furnace.

Recommended type of pressure switch: UL and FM approved for Propane fuel service.

VA Master Specification section: 23 09 11 (old 15901). www.va.gov/facmgt/standard/

VA Standard Detail: SD235239-04.pdf. www.va.gov/facmgt/standard/

Failure rate of LPFCS: 46% (BEI study of VA boiler plants.)

Make and Model: Ashcroft 0-200 psig

Fuel train operating pressure: 110 psig

Setpoint: 80 psig

Did it function properly: No

Comments: Fail setpoint-Setpoint too low. Device tripped at 80 psig. It must activate at 80% of regulated oil pressure or higher. Logic ok.

5.4.2 High Pressure Oil Fuel Cutoff Switch (HPFCS)

Purpose: Shuts down the burner if the fuel pressure rises to the setpoint. The pressure increase can be the result of a pressure regulator failure.

Recommended setpoint: Per burner manufacturer’s recommendations, which should be within

10% of the normal operating pressure.

Potential hazard from failure of the cutoff switch: A fuel pressure rise will cause the flame to become fuel-rich and potentially generate large amounts of carbon monoxide (CO) and smoke.

Change of burner firing rates or shut down may suddenly introduce more combustion air resulting in a damaging furnace “puff” when the excess fuel explodes. A fuel-rich flame is always dangerous.

Recommended type of pressure switch: UL and FM approved for propane fuel service.

VA Master Specification section: 23 09 11 (old 15901). www.va.gov/facmgt/standard/

VA Standard Detail: SD235239-04.pdf. www.va.gov/facmgt/standard/

Failure rate of HPFCS: 43% (BEI study of VA boiler plants.)

Make and Model: Ashcroft 0-200 psig

Fuel train operating pressure: 110 psig

Setpoint: 120psig

Did it function properly: No

Comments: Fail Installation -valve that can isolate switch is not lockable only in open position.

Setpoint/logic ok.

5.4.3 Low Oil Atomizing Media Pressure Switch (LAMPS)

Purpose: Shuts down the burner if the atomizing media (steam or compressed air) pressure at the entrance to the atomizing valve train is insufficient for proper atomization of the fuel oil.

Recommended setpoint: Per burner manufacturer’s recommendations and above the pressure at which the flame becomes unstable or smoky. The set point must not be lower than 80% of the minimum typical atomizing pressure.

Potential hazard from failure of the switch: Flame may become unstable, smoky, have high carbon monoxide. Flame may be momentarily extinguished and relight with a furnace “puff” that could be damaging.

Recommended type of pressure switch: UL listed for burner service.

VA Master Specification section: 23 09 11 (old 15901). www.va.gov/facmgt/standard/

VA Standard Detail: SD235239-04.pdf. www.va.gov/facmgt/standard/

Failure rate of LAMPS: 32% (BEI study of VA boiler plants.)

Make and Model: Ashcroft 0-200 psig

Atomizing train operating pressure: 84 psig

Setpoint: 65 psig

Did it function properly: No

Comments: Fail setpoint- Setpoint too low. Switch activated at 65 psig It must activate at 80% of lowest operating atomizing pressure or higher.

5.4.4 Alternative Switches for Atomizing Service:

1) Low Oil Atomizing Media/Oil Differential Pressure Switch

2) Secondary Low Atomizing Media Pressure Switch

Purpose: Shuts down the burner if 1) the atomizing media/oil differential pressure decreases to the setpoint or 2) the atomizing media differential pressure decreases to the setpoint.

Recommended setpoint: Per burner manufacturer’s recommendations and above the static pressure or differential pressure at which the flame becomes unstable or smoky. The set point must not be lower than 80% of minimum differential pressure.

Potential hazard from failure of the switch: Pressure decrease may cause flame to become unstable, smoky, and have high carbon monoxide. Flame may be momentarily extinguished and relight with a furnace “puff” that could be damaging.

Recommended type of switches: UL listed for burner service.

VA Master Specification section: 23 09 11 (old 15901). www.va.gov/facmgt/standard/

VA Standard Detail: 15622-5. www.va.gov/facmgt/standard/

Failure rate of switches: 82% (BEI study of VA boiler plants.)

Make and Model: Ashcroft

Atomizing train operating pressure: 67 psig

Setpoint: 58

Did it function properly: No

Comments: Fail Installation – Manual valve downstream of switch location must be lockable only open to prove atomizing flow to allow switch to provide full protection.

5.4.5 Automatic Oil Fuel Shutoff Valves – Leak Test

Purpose: Open-shut, normally closed valves that operate to start and stop the fuel flow to the main burner. Valves must shut tightly to prevent unburned fuel from collecting in the boiler when the burner is not firing. It is essential to have two valves in series and with leak test connections.

Recommended setpoint: Zero leakage; also called “bubble-tight”.

Potential hazard from valve leakage: Unburned fuel will collect in the furnace and may explode when burner is started. Serious damage to boiler and hazard to personnel will result.

Recommended type of fuel valves: UL and FM approved for fuel service.

VA Master Specification sections: 23 52 39 (old 15622), 23 52 33 (old 15623), 23 52 33 (old

15624). www.va.gov/facmgt/standard/

VA Standard Detail: SD235239-04.pdf. www.va.gov/facmgt/standard/

Leak Failure rate of automatic fuel shut off valves: Data not available.

Make and Model: Asco

Comments: No Leaks..

5.4.6 Automatic Oil Fuel Shutoff Valves – Proof of Closure (POC)

Purpose: Proof that the valves are closed is provided by electrical switches in the valves that sense the position of the valves, open or closed. The switches are in an electrical circuit to the burner management control system. The valves must be “proven” closed before the burner management control allows the ignition sequence to start.

Potential hazard from failure (or absence) of POC switch: A boiler explosion would occur if the pilot burner is ignited with the main fuel valves open and the furnace full of fuel.

Recommended type of POC switch: The switch is furnished with UL and FM approved automatic fuel safety shut off valves.

VA Master Specification sections: 23 52 39 (old 15622), 23 52 33 (old 15623), 23 52 33 (old

15624). www.va.gov/facmgt/standard/

VA Standard Details: None.

Failure rate of POC switches: 42% (BEI study of VA boiler plants.