The Cherne 12" Muni-Ball Plug (part #262-129) is a pneumatic bypass plug for 12" municipal sewer pipe with 3" NPT female bypass. Rated for 13 PSI / 30 ft. head pressure at 35 PSI inflation. Natural rubber inflates to seal pipes from 10.50" to 12.25" ID. At 13 lbs and 13.75" deflated length, it handles large-diameter municipal sewer mains.

Key Features

3" NPT F bypass — controlled flow-through during sewer and drain testing
13 PSI / 30 ft. head pressure — rated for sewer air and DWV testing
Pneumatic inflation at 35 PSI — natural rubber seals round and out-of-round pipe
Tether-bar compatible — holds to full head pressure with tether bar
Natural rubber — durable construction for sewer environments

Technical Specifications

Cherne Part Number	262-129
Nominal Pipe Size	12"
Usage Range (Pipe ID)	10.50–12.25"
Bypass Size	3" NPT F
Max Back Pressure	13 PSI / 30 ft.
Inflation Pressure	35 PSI
Body Material	Natural rubber
Deflated Length	13.75"
Deflated Diameter	10.25"
Weight	13 lbs
Operating Temperature	0°F to 125°F

Applications

Sewer air pressure testing with controlled bypass flow, DWV code compliance testing, municipal sewer main isolation, storm drain testing, and pipe repair work requiring temporary flow control. The bypass allows water to pass through the plug during testing rather than building up behind it. Always follow Cherne inflation and back-pressure guidelines.

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® 12 pulgadas. Enchufe Muni-Ball®, derivación de 3 pulgadas.