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Case History

The Plast-O-Matic Quality Assurance Team turns an angry customer into a satisfied — and very thankful — customer.

A leading international semiconductor manufacturer recently cut out and sent a section of pipe to Plast-O-Matic complaining of a leaking check valve, pointing to cracks on both the inlet and outlet. Cracked ports on a new valve generally indicate that the installer used a pipe wrench or channel locks, where only a strap wrench should be used. With tell-tale teeth marks on a nipple, it initially appeared that overtightening was the cause.

In this particular case, inspector Ron Cline found an unusually high number of cracks, not only on the Plast-O-Matic check valve, but also on other valves and fittings in the pipe section. Ron turned his findings over to Greg Michalchuk, Plast-O-Matic’s Quality Assurance Manager, who immediately discounted excessive elbow grease:

“If a crack develops in a PVC part due to radial stress, the crack widens under load, but usually no additional cracks develop,” Greg explains. If an additional crack were to develop, it would most certainly not form within such close proximity to the others.

A liberal amount of thread sealant was cause for suspicion. At this point, Plast-O-Matic Vice President-Sales Bob Sinclair and Technical Sales Manager Andy Ryan got involved and called our regional representative, Jim Pringle, to investigate further. The customer explained that the contractor was using Swak® anaerobic thread sealant throughout the piping system. A call was made to Swagelok Corp. to obtain a Material Safety Data Sheet, known as an MSDS.

Two ingredients in Swak® were immediate suspects: A dimethylacrylate (30 – 40%) and Propylene Glycol Azelate (20 – 30%). A spokesperson from Swagelok immediately confirmed that Swak® is an excellent sealant for stainless steel piping, but incompatible with PVC!

The customer had many of these subassemblies in-line, and in a semiconductor fab the potential loss was staggering. Proper installation techniques were used for the rest of the job, and the parts installed using the incompatible sealant were replaced prior to certain failure.

Because of Plast-O-Matic’s team effort to find the true cause of the problem, an angry customer was turned into a thankful one.