McElroy Test Caps are available for pipe sizes from 1/2" CTS to 2" IPS. They are designed for quick and easy air pressure testing of polyethylene pipe. All of our test caps are reusable, provide a positive o-ring seal, and have been pressure rated to 165 PSI to meet 49 CFR192.513. Test pressure actually improves the cap’s grip on the pipe. One test cap is required per pipe size. They are made of corrosion resistant material, and are durable in construction.