080203aA Flashcards
What is the typical pressure of low pressure natural gas? What is its maximum allowable pressure drop?
7”-14” w.c.
1” w.c. Maximum pressure drop
What is the maximum pressure between the first and second stage regulator on a propane system?
10 psi
What is the typical pressure of low pressure propane? What is its maximum allowable pressure drop?
11” w.c.
1” w.c. maximum pressure drop
If a gas installation cannot provide enough gas to an additional appliance, and upsizing the excising gas main is not practical, what may be a solution?
A new branch may be installed as long as it is with 24” of the meter outlet
Can material that has been used on previous gas installations be reused?
Yes, provided it has been cleaned, inspected and ascertained to be equivalent to new material by the person doing the work
Threaded SCH40 steel gas pipe is rated for what maximum pressure?
125 psi
What is the maximum pressure allowed on standard malleable (class 150) fittings?
125 psi
What is the maximum pressure allowed on malleable iron (class 300) fittings?
300 psi
When brazing copper tubing, what must the melting point of the brazing alloys be?
1000°F
When using compression fittings with ferrules on copper tubing, what provision must be made?
Must use a double ferrule system
All fittings used on copper gas line installations must be pressure rates for…
125 psi
Gas pressures about 125 psi require fittings designed for 250 psi
Name the copper types that may be used…
Above Ground
K, L, G
Underground
K
Types L and G are approved for underground only if they have been factory-coated with a PVC resin or extruded polyethylene
What is the only approved plastic pipe for gas?
Polyethylene
Where is the only place plastic polyethylene gas pipe may be installed?
Outdoors underground
Polyethylene is not conductive. What must be done in order to be able to locate it once it is burried?
14 gauge tracer wire
Where must polyethylene not be used in regards to propane?
Liquid propane installations
Cannot be used for the first 10’ downstream of a propane vaporizer
The minimum rated working pressure for a hose and hose fittings is?
350 psi
What is the maximum length of a hose on a permanent installation?
10’
What is the minimum/maximum length of a hose on a construction heater?
15’ min
75’ max
What is the maximum length of a hose on a portable appliance (barbecue)?
30’
A hose should not be subject to temperatures exceeding?
125°F (50°C)
A hose used on an infrared tube heater must be how long?
36” long + or - 6”
CSST(Gas tite) and tubing that are run inside a wall must be protected from damage by what?
16 gauge metal protection plates
What is the largest size of gas line that may be threaded?
2”
How many sizes must you reduce when using malleable bushings?
2 or more sizes
What is the maximum length of a flex connector on a vented appliance?
2’
What is the maximum length of a flex connector on an unvented appliance?
6’
Can you pass through a wall, ceiling, floor or partition with a flex connector?
No this is not permitted
How much unthreaded pipe must be exposed when it protrudes through a ceiling or wall?
At least 1”
How much unthreaded pipe must be exposed when it protrudes through a floor?
At least 2”
All gas lines must be buried at least how deep?
15”
24” for commercial installations where a gas line traverses a driveway or parking lot
Gas lines that are covered with concrete or paving what extends horizontally more than ___ over the line require what?
25’
Must have a vent/inspection point provided
Commercial buildings require colour coding markings how often?
Every 20’
Copper tubing installed in a residential application must have yellow bands every how many feet?
6’
Residential appliances may have the gas cock installed on the horizontal finish piping as long as is located within…
2’ of the appliance
How far away may the gas cock be located from an appliance?
Up to 50’ away as long as it is accessible and clearly tagged
What kind of valves must be used on gas piping or tubing 1” and larger and where gas pressure exceeds 0.5psig?
Ball valves, eccentric valves or lubricated plug valves
What page in the gas code can you find hanger spacing?
Pg.43
