Book 29 Ch 6 Gas Utilities Flashcards
For the purpose of leak detection, odorant is added so that as little as __-percent of natural gas in the air can be detected
1
PROPERTIES OF NATURAL GAS - The common odorant is a ___________/_____________ mix, which is used in solution of one pint per million cubic feet of gas
Mercapitan/Thiophane
Natural gas is _________ than air
Lighter
fuels such as ________ and _________, which are heavier than air; and when escaping, it will collect in low areas
Butane
Propane
Natural gas also has an ignition temperature of _____ degrees, and has a relativey small flammable range between __ and ___ percent
1100
4 & 14
Most natural gas is initially distributed through over _________ miles of transmission lines from Texas, Kansas, New Mexico, Oklahoma, Arizona, and the Rocky Mountain area
30,000
Transmission lines maintain pressures up to _____ psi and use pressure booster compressor stations, at specific intervals, to maintain appropriate flow and pressures
1000
Transmission lines bring natural gas into the Southern California area and vary in diameter from ___ to ___ inches
12 to 36
The gas is carried by service lines, as medium pressure, which normally does not exceed ___ psi
60
At the service meter (Meter Set Assembly), the pressure is reduced to a low pressure (approximately ____ psi.)
1/3
Distribution mains are generally ______________ and account for a high percentage of the mains in use today, older are steel
Polyethylene
These pipes are ________, which is the national color code for newer installations
Yellow
Older installations of plastic pipe can be ______ (salmon _______), or ________ in color
Pink
Beige
Orange
Polyethylene will have a ______ running the length of the pipe, for locating plastic gas lines, below ground
Wire
Above ground gas lines must be made of _______ and cannot be plastic
Steel