1-1/4 inch Compression Coupling. NDS PVC IPS compression fittings are used in residential and commercial DWV, Irrigation, Pool and Schedule 40 pressure applications. Compression cap should be drawn up hand tight to insure proper alignment and seating of gasket, then tighten 3/4 to 1 turn with a flo spanner wrench or strap wrench. Average torque should be approximately 25 feet lbs. on 1/2 inch through 2 inch IPS and 35 feet lbs. on 2-1/2 inch and larger IPS. Compression fittings are not for use on compressed air lines or natural gas lines. When installing the standard compression seal fittings the pipe line must be restrained from lateral movement by thorough soil compaction on straight runs and thrust blocking at change of direction or reduction in size.