OATEY 272973 Cherne® 12" T-Handle Gripper® Plug with 3/4" Bypass

The Cherne 12 inch Gripper plug is a 12 in. (300 mm) nominal size mechanical test plug. Cherne sizes its 6 in. through 12 in. Gripper plugs for concrete, clay, and SDR 26 and 35 pipe, so a 12 inch line in any of those materials is the intended fit. The 15 in. and 18 in. sizes in the same family are sized for concrete and clay only.

It is rated for 10 psi (0,7 bar) of back pressure, which is about 23 ft. (10 M) of water column. That covers a typical single-stack or lateral head test. If your test head exceeds 23 feet of water, this plug is not the right tool for the hold.

The bypass is a 3/4 in. male connection through the center of the plug. It lets you run flow, a hose, or a gauge line past the plug while it stays seated, so you can fill the line for a head test, bleed it down in a controlled way, or keep an active line draining during the work instead of pulling the plug. Cherne also builds this Gripper plug without a bypass if you only need a solid block.

The Cherne Gripper plug is rated for long-term applications, not just a short pressure test. The aluminum body and the chemical-resistant neoprene O-ring are what let it sit in a sewer or storm line through a construction sequence. Pneumatic test balls are the alternative for quick tests, but they are not what you leave in a line for an extended period.

Order Oatey/Cherne part number 272973. That number is specifically the 12 inch T-handle Gripper with the 3/4 inch bypass. The no-bypass version of the same plug is a different part, so specify the bypass when you order if you need to run a line through it.

The body is heavy-duty aluminum and the sealing element is a chemical-resistant neoprene O-ring, which is the combination Cherne specifies for plugs meant to stay in service rather than come straight back out after a test. That is the reason this style holds up in sanitary and storm lines where a plain rubber seal would degrade.