Gas Piping Flashcards
What types of gas piping materials can be used
Steel
Copper
Plastic
What schedule of black iron pipe is used for gas connections
Schedule 40
NPS stands for?
Nominal Pipe Size
What do the sizes range from in regards to the length of “nipples”
1/2” increments up to 6 “
1” increments 7”-12”
Are close nipples allowed to be used in gas systems
No
ASPT and NPT stand for what ?
American Standard Pipe Thread
National Pipe Thread
Is the pipe threads tapered
Yes
What is the approximate number of threads to be cut for a nominal pipe size of 1/2”
10 1/2
Name the different types of pipe cutters available
Single wheel and multi wheel
What tool is used to remove the internal hurt from cut pipe
Straight fluted reamer and spiral fluted reamer
Why is the use of cutting oil so important when threading iron pipe
Safeguard against poor threads, die wear, clearing debris, and heat
What type of black iron fitting is not allowed to be used for gas system
Street elbow
When ordering a balck iron tee what is the last size normally
Branch size
What is the purpose for the usage of a union
Easy quick assembly and disassembly of pipings stems
Bushing reduce pipe sizes, what is not permitted when using bushings
Nesting bushings
What must be used in every black iron connection
Teflon tape and pipe compound
Where is the pipe compound placed
Male pipe threads
How is Teflon tape wrapped on the male thread
Clockwise, 50% overlap, first two threads bare
What should not be in contact with the pipe when using a pipe wrench to tighten a fitting together
Back of the hook jaw
What is the purpose for a dirt pocket
Collects foreign materials before reaching the appliance
List the rules for a dirt pocket
3” nipple with a cap , Diana eye rod the pocket has to be the same size as the drop and has to be accessible
Can gas materials be reused
As long as they are clean and inspected
List the approved gas leak detectors
Soapy water, sniffer
What should not be used to check for gas leaks
Flame
What’s re the three classifications of copper
Malleable, ductile, food resistance to corrosion
List the copper types color
k: green
L: blue
M: red
Using stainless corrugated tubing, the appliance has to be approved, what are some of the requirements for the appliance
Suspended appliance, decorative appliance , or a direct vent room heater if it is not free standing
