Steel Pipeline Systems

a. Steel Pipe. Steel pipe (light- and standard-gauge wall thickness) is available in 20-foot lengths with diameters of 4, 6, and 8 inches. Steel pipe is coupled using a standard, two-piece split-ring coupling. The coupling uses two half-moon sections, which are bolted together over a one-piece gasket. The average time required to couple together two sections of steel pipe is 5 minutes.

b. Lightweight Steel Grooved Pipe. This pipe is made of light gauge steel with API STD5L pipe nipples welded to each end. The pipe ends are single-grooved for use with bolted couplings. This pipe comes in 20-foot sections with 4-, 6-, 8-, and 12-inch nominal IDs. Because of its thin wall, lightweight steel pipe should not be buried nor used for submerged stream crossings or in populated areas and locations where fire and damage hazards are acute.

c. Standard-Weight Steel (API STD5L) Pipe. This regular commercial-type pipe, which is manufactured to the standards of the API, is used when lightweight pipe or tubing is unavailable or unsuitable. The pipe comes in 20-foot sections grooved for coupling and in random lengths and diameters beveled for welding.

d. Bolted Coupling. This is a standard, split-ring, groove-type coupling (Figure B-1). It consists of two housing segments; two bolts and nuts; and a synthetic-rubber, oil-resistant, self-sealing gasket. The coupling and gasket are designed so that the pipe joint seals under pressure and vacuum. The coupling provides a sufficient amount of angular deflection and slack adjustment for expansion and contraction of the line between adjacent joints.
When using bolted couplings, the crew consists of a crew leader, wrenchman, wrenchman's helper, stabber, jackman, swabber, and pipe-end cleaner. The bolted-coupling crew will normally require--

• Two 20-inch hinged socket wrench handles.
• Two sockets to fit size of pipeline coupling nut and wrench.
• File.
• Dauber brush.
• Lazy board.
• Two pipeline jacks with two snakes.
• Pipeline cleaner swab with one snake.
• Wooden blocks (4 by 4 by 10 inches) with carrying rope attached.
• Full half-gallon bucket or one-gallon bucket half filled with GAA grease.
• Cleaning rags.

e. Pipe Saw, 8-Inch Capacity for Hazardous Locations. This is a reciprocating-type saw powered by an air motor. You can cut steel, cast iron, and stainless or alloy steel pipe as well as bar stock structural and rail. Use this saw to cut out a damaged portion of pipeline when operating in hazardous locations. You can operate when clearances are at minimum and you can make a straight, right-angle cut.

f. Tapping Machine. This machine is used for tapping into a pressurized pipeline to establish a service tap or to install a pressure-relief device. This operation can be done without shutting down the pipeline system. The machine uses a hole saw; a holder-pilot performs the cutting operation. He retains the separated pipe after he completes the cut and allows for its removal.

The tapping machine is lightweight and easy to operate and has an adjustable automatic-feed rate for any cutting condition. The advance rate for cutting is set by the feed-adjustment knob. This knob engages a friction-type clutch that automatically regulates the feed rate. The operator loosens (slow feed) or tightens (faster feed) the feed-adjustment knob to obtain the correct amount of force for the task. The machine comes with a ratchet crank for manual operation.

g. Deadweight Tester. This tester is used to calibrate pressure gauges, verify the set points of spring-loaded relief valves, and provide precise pressure readings for pipelines. The tester uses known weights that directly correlate to known pressure gauges and the verification of set points for spring-loaded relief valves.