PV-LOKTM Series PWM for DI Fitting Restraint (CIOD)

Features & Advantages:

The PV-LOKTM Series PWM restrainer incorporates a series of machined, serrations that effectively engage PVC pipe walls, to provide positive joint security and full support of the pipe. The PV-LOK Series PWM is designed for use with ductile iron ttings meeting AWWA/ANSI C153/A21.53 and C110/A21.10 having either a mechanical joint or a push-on joint with ear lugs. The Series PWM incorporates a PV-LOK clamping ring, and elongated T-bolts or restraining rods depending on nominal size.

Sample Specification:

Restraint devices for joining plain end PVC pipe to either mechanical joint or push-on joint with ear lug watermain ttings shall consist of a split retainer ring that incorporates a series of machined serrations (not “as cast”) that provide positive restraint, exact t and full support of the pipe wall. The restraint device shall provide the necessary bolts and nuts to complete the water main fitting assembly. Devices shall carry a minimum 2:1 safety factor and meet or exceed the recognized testing for restrained joints on PVC pressure pipe and offer factory certi cation and independent test results. Restraint devices for securing PVC pipe to mechanical joint/push-on joint watermain ttings shall be SIGMA PV-LOKTM Series PWM or approved equal.


  • Clamping ring is manufactured of high strength ductile iron in accordance with ASTM A536, grade 65-45-12.
  • Side clamping bolt and hex nuts are high strength steel in accordance with ASTM A449 and zinc plated to B633, Type III Sc.1 for corrosion resistance.
  • Extra long T-head bolts and nuts are high strength, low alloy steel in accordance with AWWA/ANSI C111/A21.11. Restraining rods and heavy hex nuts are of high strength, low alloy steel in accordance with AWWA/ANSI C111/A21.11. T-head bolts and restraining rods provide minimum 45,000 psi yield and 60,000 psi tensile strength.