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
What is the minimum depth for underground piping?
15” but 24” under any commercial driveway
What is the minimum size for a dirt pocket?
3 inches
What is the minimum spec for a hose?
350 psig working pressure
What is the minimum test for rough in piping?
15psig for 15 minutes
What kind of fittings can you use in welded pipe installations?
Manufactured only, not field fabricated
What kind of labeling does gas line need in commercial or industrial applications?
A yellow mark or any labeling that indicates it’s gas line at least every 20ft
What locations are not suitable for gas line installations?
Stairwells (doesn’t include residential), chimneys, flues, elevator shafts and some others
What needs to be done to piping when passing through concrete or brick?
It needs to be protected from the corrosive effects of those materials
What materials can gaskets used in gas systems be made of?
Not rubber, has to be synthetic or cork.
What range should the gauge you’re using have?
It should exceed the pressure by 15% but not by more than 300%
What type of copper requires no special coating?
Type K
What type of copper comes coated?
Type L
When can threaded bushings be used on gas lines?
When they’re approved
When can you leak test and not pressure test gas line additions?
When they’re less than 20ft and below 0.5 psig
Where are dirt pockets located?
In the gas pipe at the bottom of the final drop to an appliance
Where can you find the Btu input of an appliance?
The rating plate, installation instructions, or by contacting the manufacturer
Where must Unions and Swing joints be installed?
Anywhere that is not concealed as they can loosen over time.
