GPT Preventive Maintenance Procedures 3 — Questions and Answers
Question 1: What does a pressure drop test during a PM inspection indicate if the drop exceeds the allowable threshold?
- The system has been recently upgraded
- There is likely a leak somewhere in the piping system (Correct answer)
- The gas meter needs replacement
- The appliances are operating at peak efficiency
Correct answer: There is likely a leak somewhere in the piping system
An excessive pressure drop during a static or operating pressure test is a primary indicator of a gas leak in the piping system.
Question 2: Which of the following is a key preventive maintenance task for gas meters in a multi-unit building?
- Painting the meter for corrosion protection
- Verifying meter index readings and checking for corrosion or physical damage (Correct answer)
- Replacing all meter diaphragms annually
- Relocating meters indoors to prevent weather exposure
Correct answer: Verifying meter index readings and checking for corrosion or physical damage
During PM, technicians should verify meter readings for billing accuracy and inspect meters for corrosion, damage, and proper clearances from heat sources.
Question 3: When checking pipe hangers and supports during a PM inspection, which finding warrants immediate repair?
- A hanger with a painted surface
- A missing or broken support that allows the pipe to sag or stress at a joint (Correct answer)
- A support spaced exactly per code requirements
- A hanger made from galvanized steel
Correct answer: A missing or broken support that allows the pipe to sag or stress at a joint
Missing or broken supports allow pipes to sag, creating stress at joints and fittings that can lead to leaks or joint failure.
Question 4: What is the recommended practice when performing a PM on a gas system that serves critical equipment (like a hospital boiler)?
- Perform PM during peak demand hours to test under load
- Schedule PM during planned outages and notify all affected parties in advance (Correct answer)
- Skip the shutoff test to avoid interrupting service
- Only inspect the meter and skip internal piping
Correct answer: Schedule PM during planned outages and notify all affected parties in advance
Critical systems require coordination with facility management so planned outages can be arranged, preventing unplanned service interruptions during maintenance.
Question 5: During PM on an underground gas service line, what condition should a technician look for at the point where the pipe enters the building?
- Pipe color is yellow
- Proper sealing of the pipe sleeve to prevent gas migration into the building (Correct answer)
- The pipe is metallic, not plastic
- Depth markings are present on the exterior wall
Correct answer: Proper sealing of the pipe sleeve to prevent gas migration into the building
The wall penetration sleeve must be sealed to prevent any gas that escapes underground from migrating into the building structure.
Question 6: A technician finds a gas pipe with a coating showing significant peeling and rust pitting during a PM inspection. What is the correct action?
- Repaint only the surface with standard exterior paint
- Document, wire brush clean, apply approved coating, and flag for follow-up replacement if pitting is deep (Correct answer)
- Wrap the pipe in duct tape as a temporary fix
- No action needed if gas is still flowing
Correct answer: Document, wire brush clean, apply approved coating, and flag for follow-up replacement if pitting is deep
Surface preparation, application of an approved corrosion-resistant coating, and documentation are required; deeply pitted pipe may need full replacement.
Question 7: What does NFPA 54 require regarding the accessibility of gas shutoff valves for maintenance purposes?
- Valves may be buried or concealed if labeled
- Valves must be accessible and operable without removing permanent construction (Correct answer)
- Valves only need to be accessible to the utility company
- Accessibility requirements apply only to valves over 2-inch diameter
Correct answer: Valves must be accessible and operable without removing permanent construction
NFPA 54 requires that shutoff valves be located where they are readily accessible for operation and maintenance without removing any permanent building component.
GPT Preventive Maintenance Procedures 3
What does a pressure drop test during a PM inspection indicate if the drop exceeds the allowable threshold?