One method of restraining a pipeline is to provide a welded-on thrust collar or other dependable anchorage means on one or both sides of the point requiring restraint and to use concrete poured around the collar for support against undisturbed soil surrounding the pipe.
At a bend, the fitting and pipe ends would have to be of a restrained type, adequate to withstand total thrust involved. The required number of thrust collars would be dependent on the magnitude of the thrust force to be restrained and the allowable load per collar.
Thrust collars are also used in lieu of water stops on fabricated wall pipe for installation in load-bearing walls to resist thrust caused by internal pressure.
Fittings are manufactured of ductile iron, grade 70-50-05 (minimum tensile strength: 70,000 psi; minimum yield strength: 50,000 psi; minimum elongation: 5%) in accordance with AWWA C110 or C153.
All pressure ratings shown are AMERICAN’s suggested standard and are for water service.
“Thrust Collars” are designed to accomodate the force generated by the pipe line operating at the rated working pressure. “Wall Collars”, also called “Water Stops”, are intended to prevent leakage through a wall. The wall collar does not meet the requirements for a thrust collar.
Weights of fittings can vary due to changes in foundry practice.
