The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
Plumbing Repairs And Utilities
Gas And Air Piping
23. General
This section discusses installation of air and gas piping for heating, cooking, and other purposes in- side buildings. For detailed information on gas distribution systems and gas-burning equipment, see TM 5-648 and 5-652 (when published).
24. Installation Standards
General standards for installing gas and air piping are outlined below. For further information on gas piping, see OCE Specifications, section XXXVIII. (See app. I.)
a. Use galvanized steel or galvanized genuine wrought-iron pipe and galvanized threaded fittings. For details on cutting, threading, and joining threaded pipe, see paragraph 8.
h. Install piping without burrs or other obstructions or defects.
c. Remove split fittings, fittings with sand holes, or piping found defective after installation and replace with new material.
d. Do not install unions or bushings in walls or other concealed places. Check cast-iron fittings carefully for sand holes. Use malleable-iron fittings if possible.
e. Protect piping installed in concrete or cement with tarpaper or heavy building-paper covering.
f. Grade all gas and air piping to a low point and provide accessible drip pockets with a nipple and cap.
g. Make all equipment connections solid, making the final exposed connection with a union or a right- and-left nipple and coupling.
h. Provide all equipment with a separate shut-off for ready repair or disconnection.
i. Where automatic devices are used on gas-fired equipment, provide an additional dependable device
to shut off pilot and main burner if pilot flame is extinguished.
j. Install underground piping below freezing level and insulate horizontal piping exposed to cold temperatures to prevent freezing at points where water may collect.
k. Do not use welding on alterations or repairs to existing gas lines. Welding heat may ignite residue in pipes and cause damage to building.
l. Use special care and install special equipment for use with liquefied petroleum gases. These gases, being heavier than air, drop to low points of floor or ground channels and may cause explosions or fires if ignited.
m. Change burners or appliances designed for manufactured or natural gas if they are to be used with propane or butane gas.
n. Dope all joints in piping and equipment for liquefied petroleum gas with Watrola Gum or an equivalent compound insoluble in this type gas.
25. Inspection of Piping
After installation, inspect and test all new piping for leaks, as follows:
a. SMALL INSTALLATIONS. Test installations involving only a few joints by spreading soap solution on each joint and watching for bubbles.
b. EXTENSIVE INSTALLATIONS. Test extensive installations with air pressure and mercury gauge.
