Push Fittings (push to connect fittings) are best known under the SharkBite brand and are sold on PexUniverse.com under the OmniGrip brand. These are also available elsewhere under the names such as TECTITE, PROBite, GatorBite and possibly others.
OmniGrip push fittings are fully compatible with SharkBite fittings and can fully replace the latter.
They can be used with standard PEX, copper and CPVC pipe sizes.
A sharp rise in popularity of push fittings over the past few years has been accompanied by a rising number of complaints about leaks, prompting us to investigate the matter. Since push fittings were originally used for the naval industry (with all its strict requirements) and have proven to be reliable, it would be quite abnormal for them to fail in regular residential settings.
Most of our findings point to the conclusion that most, if not all issues, arise from improper use and installation practices. Yes, push fittings are quick, convenient and easy to use, but like any plumbing component, have certain limitations which we listed below:
Don'ts
Never use hacksaw or band saw to cut the pipe – it’s a recipe for disaster. For copper pipe, use only a standard copper pipe cutter. In case of PEX, only use a
PEX pipe cutter. Always make a clean, square cut.
Avoid reusing push fittings. The O-ring inside the fitting has a food grade lubricant applied to it, which is gradually wiped off when pipe is removed and re-inserted or fitting is re-used. While some companies allow reusing the fitting up to 4-6 times, we advise against this practice whenever possible or to limit it to 2-3 times.
Do not sand the copper pipe – while it’s the easiest way to smooth out the edge of the pipe, this practice should be avoided whenever possible since it disrupts the otherwise even pipe surface and may compromise the seal. It is only acceptable when a very fine sanding paper is used and only over the edge of the pipe in light circular motion.
Avoid push fittings in systems with glycol – some installers have voiced their concern about leakages in glycol system using push fittings. What we’ve found is that the issue is high likely not with the EPDM seal (the O-ring), but the lubricant, which may react with glycol, causing the deterioration of the seal and subsequent leakage.
Do not use pipe thread sealants, tape, lubricants or glue. Not only these are unnecessary, but can compromise the connection.
Do not use with PEX-AL-PEX. In fact, push fittings are only intended to work with copper,
PEX or CPVC pipe. 1/2" PEX-AL-PEX has an OD very similar to that of 1/2" PEX, but due to the composition and properties of the pipe, cannot and should not be used with push to connect fittings.
Do not install these outdoors. POM polymer used in push fitting construction (the visible plastic "collar") is not rated for continuous UV exposure and will become brittle over long periods of exposure to sunlight.
Do's
Cut the copper pipe gradually. Make sure the cutting blade (ring) is sharp. Avoid using excess force as this will deform the pipe from the original round shape and will require more deburring.
Outer edge of the copper pipe must be reamed clean – we advise to ream/deburr the inside also to reduce turbulence. When pipe is not reamed or reamed improperly, abrasive edges may cut the O-ring which seals off the water. In fact, lack of or improper reaming is probably the most contributing factor to O-rings failure.
Measure – pipe must be fully inserted into the fitting to a depth specified in instructions. The depth is the same for OmniGrip and SharkBite fittings, so a SharkBite depth gauge & deburr tool can also be used with OmniGrip. When pipe is not fully inserted, it will leave room for leakage.
Use PEX stiffener (insert) when using push fittings with PEX tubing. Stiffeners included with SharkBite, OmniGrip and other brand fittings help to maintain a round shape of the PEX pipe to assure a proper water-tight seal. They are required, not just recommended.
When disconnecting a push fitting, always use a designated disconnect clip. Do not use screwdrivers, knives or any other tools, as they may damage the fitting and render it unusable.
When/if removing a PEX stiffener (insert) from the push fitting – do it properly. Hold the insert with needle-nose pliers and push on the lip of the fitting with a disconnect tool (in the same manner a pipe is disconnected), while slowly but firmly pulling the insert out.
Pressure test. Like any other system, installed push fittings must be pressure-tested prior to being put into use. We recommend testing with air for new systems. You can find more information on pressure testing a PEX system
here.