Case Histories » Industrial

Solvent Cement Welding of PVC Piping

Poor plumbing workmanship
Long length of non-fused joint would indicate a solvent cement with too low viscosity had been used during the solvent cement welding – indicating poor plumbing workmanship
Inadequate amount of solvent cement had been applied to the joint
The very unusual “hoar frost” bonding pattern on the bond surface indicates inadequate amount of solvent cement had been applied to the joint

Solvent Cement joining is used to join vinyl pipe, polyvinyl chloride (PVC), and Chlorinated Polyvinyl Chloride (CPVC). As the pipe diameter increases, so does the difficulty in installing it. To assume proper workmanship, attention to the following procedures should be taken:

  • The size of the joining crew should be increased:
    • 6-inch – 8-inch pipe: two to three people per joint
    • 10-inch – 24-inch pipe: three to four people per joint
  • The end of the pipe must be chamfered as per the pipe manufacturer’s specifications.
  • The primer and cement should be applied simultaneously to the pipe and fittings
  • Ensure the application of a second full layer of cement to the pipe
  • Because of the short sockets in many large diameter fittings, it is essential to have pipe bottomed into the fitting. It is for this reason that above 6-inch diameter we recommend the use of a come-along to press the pipe into the fitting.

Testlabs International has the experience and laboratory facilities to evaluate the workmanship and integrity of solvent cement welded joints in large diameter (6-inch diameter and above) pipes as indicated in the polished longitudinal section through a solvent cement joint. The inadequate application of solvent cement is highlighted in the second image of an inadequate bond surface.