PV-LOKTM Series PWP for use on Ductile Iron Pipe

Features & Advantages:

The PV-LOK Series PWP serration-style clamping ring may successfully be used for the restraint of bell and spigot ductile iron pipe joints manufactured in accordance with AWWA/ANSI C150/A21.50 and AWWA/ANSI C151/A21.51. Rated pressure of the restraint system for ductile iron pipe is shown in the table below.

Sample Specification:

Bell joint restraint devices for ductile iron pipe in sizes 4-12 shall consist of two serrated clamping restrainer rings. One ring shall be installed on the spigot pipe and connected to the second ring on the bell end pipe with restraining rods and nuts. Restraint devices shall incorporate a series of machined serrations 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 pipe bell joint restraint assembly. Restraint devices for securing ductile iron pipe bell joints in sizes 4-12 shall be SIGMA PV-LOKTM Series PWP 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.
  • Restraining rods and hex nuts are of high strength, low alloy steel in accordance with AWWA/ANSI C111/A21.11 and provide a minimum 45,000 psi yield and 60,000 psi tensile strength.