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Pipe Assembly


Installation Sheet

Assembly of PVC Gasketed Pipe
Northern Pipe Products Inc. gasketed PVC pipe has a factory-installed rubber ring joint. This locked-in-place design prevents fishmouthing or accidental dislocation of the sealing gasket when pipe spigots are inserted in the bell joint. Do not attempt to remove the gasket from the gasket groove. The pipe-coupling gasket should be carefully inspected and cleaned to insure that no dirt or foreign matter is between the gasket and the pipe. After the pipe is placed in the trench the coupling should again be inspected to confirm that no dirt is in the gasket groove area. Pipe lubricant should be placed on the gasket face and on the spigot end of the pipe to the insertion line. Make certain the pipe end is supported off the ground so the lubricant does not pick up dirt. The pipe then should be inserted into the bell, aligned, and carefully pushed past the gasket. The spigot insertion mark is a “reference mark” to indicate the proper depth of insertion.  In a properly assembled pipe-to-pipe joint, the insertion mark is flush with the lip of the adjoining bell. Care must be taken to insure that the spigot is not over-inserted. Use extreme care when assembling gasketed pipe with bar and block method or a  machine such as a backhoe to prevent joint misalignment or over-insertion. Do not swing or stab the joint together. If the pipe does not go into the bell to the insertion mark, this may be an indication of a pushed gasket. A feeler gauge can be used to determine the position of the gasket in the coupling. If pipe assembly is at the trench side and then lowered, the same procedure is followed. As the pipe is lowered into the trench, holding pressure should be exerted on the end of the pipe, thus preventing movement in the bell after insertion. The pipe should be inspected to insure no lessening of insertion depth has occurred. Usually pipe larger than 8" diameter is assembled in the trench. Field cutting the pipe may be necessary. Square cuts are essential. Northern Pipe Products Inc. recommends the use of a wheel type cutter and a mechanical beveler to complete the cutting procedure. After the cut is made, the pipe should be beveled smoothly to the original degree of the factory bevel. Fittings are usually gasketed slip joint fittings manufactured from PVC. Care must be taken to avoid rolling or cutting the fitting gasket. The same lubrication procedure used on the pipe is recommended for placement of the fitting.


Assembly of Solvent Welded Pipe
Solvent welding or cementing pipe joints may be selected as an alternate method of installation. Although the pipe is of the same material as that with a gasket joint, the method of connecting the pipe is quite different. Clean and dry the spigot and bell socket of all dirt, moisture, and grease. Using a clean brush or applicator, coat the inside of the socket with cleaner solvent. Avoid puddles or amounts of standing solvent in the coupling. Apply a coat of cleaner solvent to the spigot end of the pipe. Apply the filler solvent cement to the spigot end of the pipe ONLY. Rebrush the bell socket quickly with cleaner solvent. Push the spigot into the socket, turn 1/8 to 1/4 turn pushing the pipe completely into the bell socket making sure the spigot bottoms out at the full socket depth. Hold firmly until the joint is set up (usually a matter of seconds). As the pipe is joined, a bead of solvent should appear at the outside edge of the socket. Wipe off the excess solvent with a clean rag or paper towel. Final setup and curing time varies depending on pipe size, temperature, and humidity. Longer setup time is necessary in colder weather. More care is needed to be sure the welding solvent has cut into the pipe. Allow at least 24 hours before testing the joint. More workers may be needed to handle larger diameter solvent welding. In sizes above 6" diameter, three workers are typically used, two to make the solvent joint and one to insert and turn the pipe.