Introduction to Gasfitting Codes and Regulations - Part B Flashcards
All plastic gas lines being buried must have a what?
Tracer wire so it can be energized to search for the pipe.
Can gas pipe be used as a conductor?
Only!! if it’s incorporated as part of the flame safeguard of the appliance.
Can piping pass under a foundation or footing?
No.
Can you repair defective pipe or fittings?
No, it must be replaced.
Do you need to increase the pipe size of the existing gas line when tapping into it within 2 feet of the gas meter/regulator?
No.
How do you install gas lines in concrete?
Encased in a duct having both ends open to the atmosphere with at least 1/2” air space around the pipe or
Suspended in a trench with a removable top that is not airtight.
How do you test finish piping?
With soapy water solution and a 10 minute meter test dial test
How does residential gas piping need to be labeled?
The same as commercial but every 6ft instead of 20ft
How far away can a gas cock be installed from an appliance for residential purposes?
Up to 50 ft as long as it’s accesible and clearly tagged
How far from the edges of a member do holes have to be?
2 inches minimum and the hole diameter must not exceed more than a 1/4 of the member depth
How far must a purge point be from the building?
At least 10ft
How is pipe dope applied?
To the male threads so that excess dope is forced out of the pipe rather than pushed into it.
If you’re installing larger gas line to existing tubing, where do you install it?
Within 2 feet of the gas meter/regulator
Minimum size for a pressure test gauge for gas
3 inches
What are the fittings required to make a drip/dirt pocket?
- A tee
- A cap
- A nipple
What are the maximum temperatures a hose can be subjected to?
125F
What are the restrictions to using a hose?
It shall not exceed 10ft and cannot pass through any sort of wall or barrier.
What circumstances is a hose used for?
Commercial or industrial work where it’ll be exposed to vibration, expansion, contraction
What do you need to be careful about when purging gas lines larger than 4”?
You need to remove all the air used in a pressure test with an inert gas prior to allowing gas to enter the system to avoid dangerous gas/air mixtures
What color of teflon tape is approved for gasfitting?
Yellow, pink, light orange, or light green (they are thicker)
What is needed on piping that will be exposed to a corrosive atmosphere?
Painting or coating.
What does a dirt pocket do?
Collects scale, fillings, and foreign materials that may be in the gas line.
What is the maximum allowable pressure drop in a high pressure system (above 14”wc)?
50% of standing pressure
What is the maximum allowable pressure drop on a low pressure (7-14”wc) system?
1” wc
