PV-LOKTM Series PWPF for PVC Fitting Restraint (CIOD)

Features & Advantages:

The PV-LOKTM Series PWPF 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 directional gripping action maximizes restraint during increased line pressures such as those resulting from surges and water hammers. The Series PWPF incorporates a PV-LOK clamping ring, restraining rods, and two piece beveled back up ring for the PVC tting to provide the necessary joint restraint.

Sample Specification:

Restraint devices for joining plain end PVC pipe to gasketed PVC pressure ttings shall consist of a split clamping ring that incorporates a series of machined serrations (not “as cast”), providing positive restraint, exact fit and full support of the pipe wall. Restraining rods and nuts shall connect the restrained pipe end to a two-piece, beveled backup ring that seats comfortably behind the PVC gasket fitting bell. In applicable sizes, the interlocking ear or two piece design on the back-up ring shall provide tongue-and-groove seating to eliminate exing under increased pressure and surges. In applicable sizes, the multi-part back-up ring shall utilize side clamping bolts to assemble behind the tting bell. Devices shall carry a minimum 2:1 safety factor and meet or exceed the recognized testing standards for restrained joints on PVC pressure pipe and offer factory certi cation and independent test results. Restraint devices for joining PVC pipe to PVC gasketed pressure ttings shall be SIGMA PV-LOKTM Series PWPF or approved equal.


  • Serrated Clamping Ring and beveled backup ring: ASTM A536 65-45-12 ductile iron.
  • Side Clamping Bolts and Hex Nuts: ASTM A449 high strength steel, zinc-plated.
  • Restraining Rods and Hex Nuts: High strength low alloy steel (AWWA/ANSI C111/ A21.11) 45,000 psi yield / 60,000 psi tensile.