So You Need Pipe Plugs … Now What?
COB Industries manufactures and distributes pipe plugs, pipe stoppers and test plugs for just about any application so let us help you determine the right type/style of plug for your situation. When someone calls us about pipe plugs, we basically need to know the answers to a few questions in order to determine what type of plug would be the best option…what size?, what does the plug need to hold back, how much back pressure, and how long is the plug going to be in place? Other issues (chemicals / temperature, etc.) may have to be considered as well.
Here is a quick breakdown to help determine the type of plug that is needed:
VERY LOW PRESSURE / NO PRESSURE PLUGS — For FME (Foreign Material Exclusion) applications, or to just block off the pipe to keep debris out or block fumes…Take a look at our Bag Plugs, Nylon Expansion Plugs or Cast Aluminum Expansion Plugs. We also have other Low Pressure Expansion Plugs.
Bag plugs are for use wherever a plain rubber bag would not hold. This covered bag consists of an inner bag made of a high quality Natural Rubber bladder that is then encased in a 100% Polyester fabric cover. The gauge of rubber and polyester vary with the size of the bag. Each size bag is expertly made to insure a snug fit and good shut-off when inflated. Inflating valves are standard with each bag; pressure gauges are recommended and can be furnished at an extra cost. Covers can be made flame retardant and bladders can be supplied in hydrocarbon-resistant Nitrile Rubber at an extra cost.
DO NOT use Natural Rubber Type “C” Bags in oil, gasoline, kerosene, acids or any similar substances. Contact us for specific recommendations when bags are to be used in lines containing these substances.
OUR TYPE “C” BAGS ARE GREAT FOR OIL AND GAS MAINS AS WELL AS FME (FOREIGN MATERIAL EXCLUSION) WORK!
Nylon Plugs are versatile tools suitable for a multitude of applications. They are primarily used for leak testing of pipework fabrications or to prevent the ingress of dirt, vermin, or other unwanted materials. These plugs are constructed from injection-moulded, high-grade nylon components and rubber rings, offering a lightweight, non-rusting, and easily expandable solution that can be dismantled for cleaning purposes.
Cast Aluminum Expansion Plugs are specifically designed for heavy-duty applications and is suitable for arduous duties such as immersion in chemicals and/or exposure to higher temperatures.
Mechanical Low Pressure Expansion Plugs featuring a T-handle or Snap- handle design, high-expansion neoprene rubber, and plated steel hardware to create secure, low-pressure seals in circular openings and pipe ends.
Materials and Design
- Body: Ribbed neoprene rubber for a tight, non-slip grip inside holes.
- Handle: Easy-to-turn brass T-handle for manual expansion without extra tools.
- Hardware: Zinc-plated or stainless steel metal plates.
Performance and Uses
- Pressure ratings: Handles low air pressure (typically up to 5 to 10 psi) and water head pressure (roughly 11 to 23 feet), varying by plug size.
- Applications: Used across industrial and commercial settings to seal pipe ends, block off test holes, or temporarily plug circular openings.
- Sizing: Available in fractional and specific diameters ranging from small 1/2-inch sizes up to large 4-inch pipe applications.
VALVE REPAIRS / TO PLUG OFF BEHIND A VALVE — Qwik-Gate Pipe Plugs are used to change out valves, add fittings or make line repairs without shutting off the water or draining the line. These pipe plugs are good for up to 65 PSI and are designed to be pushed into the pipe and actuated from outside the pipe.
NEED TO SEAL A PIPE BUT ONLY HAVE SMALL ACCESS TO INSERT / REMOVE THE PIPE PLUG — Use the Qwik-Fit Cylinder Plugs when there is a need to hold back small amounts (low pressure) of water with reduced access to the pipe. For higher back pressure applications see the Multi-Size Inflatable Pipe Plugs / Stoppers
STANDING WATER, HEAD PRESSURE UP TO 40 FT, BACK PRESSURE UP TO APPROX. 20 PSI — for pipeline repair / maintenance, water and sewer applications…we offer Multi-Size Inflatable Stoppers from 2” diameter to 96” diameter, and Disc Plugs from 24” and up. Both styles offer threaded bypass / test ports.
WATER PRESSURE / BACK PRESSURE up to 150 PSI — For applications involving higher backpressures or pressure testing up to 150 PSI, we have inflatable Medium-Pressure Roll-up Plugs with a braced pressure rating of up to 150 PSI
The Qwik-Sealfast Plugs which are self-restraining Pipe plugs (no additional bracing or restraining required) that have set-screws that hold the plug in place and are available with either an inflatable or mechanical seal. These pipe plugs are made to order to suit almost any application.
EXTRA LARGE DIAMETERS, CUSTOM APPLICATIONS, SUB-SEA PIPE PLUGS, ETC.— See our Custom Pipe Plugs page or call to speak to one of our design engineers about your application.
