The Cherne 4" Inside-of-Pipe Gripper (part #270-296) is a mechanical test plug that seals inside the bore of 4" pipe — position it anywhere along the run, not just at the end. Rated for 17 PSI / 40 ft. head pressure. Fits 4" Schedule 40 and Schedule 80 PVC, ABS, and cast iron pipe (usage range 3.80"–4.06" ID). At just 2.5" long and 0.50 lb, it slips easily into the pipe and locks in place with the wing nut. Unlike the End-of-Pipe Gripper, the inside-of-pipe design lets you isolate a specific section between two access points.

Key Features

Inside-of-pipe design — position the plug at any depth inside the pipe, not just at the end
17 PSI / 40 ft. head pressure — meets code requirements for DWV and sewer air tests
Mechanical wing nut expansion — no inflation needed, no gauge to carry
Natural rubber O-ring — seals round and out-of-round pipes with excellent memory
Zinc-plated hardware — carriage bolt and extra-large wing nut resist rust and corrosion

Technical Specifications

Cherne Part Number	270-296
Nominal Pipe Size	4"
Usage Range (Pipe ID)	3.80–4.06"
Max Back Pressure	17 PSI
Max Head Pressure	40 ft.
Body Material	Glass-reinforced ABS plastic
Seal	Natural rubber O-ring
Hardware	Zinc-plated carriage bolt, extra-large zinc wing nut
Operating Temperature	0°F to 125°F
Length	2.5"
Weight	0.50 lb
Pipe Compatibility	Schedule 40 & 80 PVC, ABS, cast iron (no-hub, service weight, extra-heavy)

Applications

Isolating a section of 4" pipe for DWV testing, stack testing where the plug needs to sit below a fixture connection, sewer air tests, and any scenario where you need the plug positioned inside the run rather than at the opening. Standard tool for plumbing contractors doing residential and commercial inspections.

Questions on sizing or bulk pricing? Call (866) 514-3684 or email us — same-day shipping on in-stock items, tax-exempt purchasing for qualified accounts.

Cherne® 4" Inside-of-pipe Gripper® Plug,17 PSI - 40 ft.