Gas Main Fitter

Lay pipes to repair and extend nonwelded gas mains.

What does a Gas Main Fitter do?

Lays pipe to repair and extend nonwelded gas mains and to install or repair service pipes between mains and residences: Drills hole in section of main to which new pipe will be fitted and inserts inflated rubber bag to seal off flow of gas. Removes faulty pipe by unscrewing bolts at joint with hand wrench. Lays gas mains by fitting spigot end of one pipe section into bell end of another. Bolts joints together. Places wooden blocks under pipe to adjust pipe to line and grade, testing gradient with carpenter’s level. Fastens steel cap over free end of gas-main extensions. Drills hole or installs reducing fitting in main where service pipes begin. Bolts saddle clamp around main, preparatory to welding. Drills hole through welded saddle clamp into main, using power drill. Cuts, threads, and screws together sections of pipe forming service line, and lays service line in trench. Bolts end of service line to saddle clamp, using special compression coupling to produce gas-tight connection. Removes rubber expanding bag to resume flow of gas and caps holes with screw plugs. Installs various gas-main attachments, such as drips, ells, and tees. Tests pipe for weak joints by forcing air into pipe with air compressor and coating joints with soap and water, and notes formation of bubbles, indicating leak. Tightens bolts or repairs leaky joints. May install gas meters. May install pipes beneath roads, lawns, or locations where not feasible to dig trenches, by forcing pipe through earth with special pipe jack. May direct crew in excavating trench and positioning pipe. May fuse bonds to pipe joints, using holder and flash chemicals, to concentrate high temperatures at point of fusion. May install and repair service lines only and be designated Pipe Fitter, Street Service.