OATEY 265048 Cherne® 4 in.- 6 in. Muni-Ball® Plug 3/4 in. Bypass

The Cherne Muni-Ball 265048 covers 4 in. through 6 in. (100 to 150 mm) pipe, so one plug handles a range of lines instead of a single diameter. Deflated it measures 3.46 in. (88 mm) in diameter and 10.75 in. (273 mm) long, which is what has to pass through the cleanout, manhole opening, or pipe end before you inflate it.

Inflate to 35 psi (2,4 bar) and no higher. Once set, the Muni-Ball 265048 holds a maximum back pressure of 17 psi (1,2 bar), equal to 40 ft (12 M) of head. If your test column or standing water exceeds 40 feet, this plug is not the right one for that run.

The bypass is a 3/4 in. female port straight through the plug. It lets you keep flow moving through a line you have plugged, or run a test line or pump hose past the plug, so you can work in a live sewer without backing it up. Cap or valve the 3/4 in. F port when you want a dead block.

Yes. The Muni-Ball is natural rubber, which expands and recovers its shape, and it is built to seal both round and out-of-round pipe. That is the main reason it gets used in older clay and deteriorated municipal lines where a rigid mechanical plug will not make a seal.

The inflation thread is 1/8 in., so your air hose or gauge assembly has to land on that thread. The inflation valve is removable: if it is damaged you replace just the valve, and you can also swap it for a quick disconnect fitting if you are setting and pulling plugs repeatedly.

It carries a single 1/4 in. chain eye bolt. Shackle a rope or retrieval chain to that eye before you push the plug in, since an inflated plug in a live line can move and you want a positive way to pull it back. The plug itself weighs about 2.5 lb, so hand retrieval is practical on a 4 to 6 in. line.

Both. Model 265048 is used to block flow and also as a back plug for sewer air testing, with the 3/4 in. F bypass giving you the port to run your air line or gauge through to the test section.

Pick the bypass version, like the 265048 with its 3/4 in. F port, when the line has to keep flowing while you work downstream, or when you need to run an air or test line through the plug. A solid plug with no bypass is the choice for a straight dead block where nothing passes. Both seal the same way, by inflating the rubber body against the pipe wall at 35 psi.

Capacity is 0.109, so it is a small-volume plug that a portable compressor or a hand pump can bring up to its 35 psi (2,4 bar) inflation pressure quickly. Use a gauge rather than filling by feel, since overinflation is the common way these get ruined.