Cherne 270008 Test Ball Plug Ring & Chain 3.75" Deflate L trap

Test Ball Plug for 3/4 in to 1-1/4 in Pipes

The Cherne 270008 is a pneumatic test plug designed to seal pipe interiors during pressure testing. It fits pipes with inside diameters from .75 in up to 1.25 in. The plug inflates through a tire-valve air connection and includes a tether ring and chain for retrieval. It is intended for plumbing professionals and maintenance crews performing leak tests on drain, waste and vent systems.

Inflation Limits and Deflated Profile

The plug deflates to a diameter of .73 in and a length of 3.75 in, allowing insertion through clean-out openings or test tees. It must not be used in pipes smaller than .75 in or larger than 1.25 in inside diameter. The tire-valve connection accepts standard inflator chucks; no bypass or threaded air ports are provided. Over-inflation beyond the rated pipe range can rupture the plug or damage the pipe.

Installation Notes and Common Issues

Insert the deflated plug, inflate until the pipe is sealed, then monitor pressure throughout the test. The textured body surface improves grip against pipe walls. Common problems include using the plug outside its diameter range, which causes slippage or blow-out, and losing the tether chain down the line. Always verify pipe inside diameter before selecting this model.