Tech Topic: Push-and-Twst Pipe Joining
There is more than one way to join pipes in the plumbing world
There’s no doubt about it – a nicely sweated copper joint in a piping system can bring a tear to an old plumber’s eye. Perfectly sweated copper joints are still, even in 2017, the mark of a skilled tradesman, a plumber who can get the job done leak-free and leave his customers with a little bit of art hanging on their walls or, perhaps, hidden behind drywall.
Over the years, different ways of joining copper have evolved. You’ve got your soldering and brazing, of course. You also have tools that will press a crimp in your copper, thus making a good, solder-free seal. This is perfect for large diameter pipes and in areas where you might not want to be soldering.
The press tools are great, but and sometimes getting them into tight spots can be difficult. Enter another, fairly new, development in pipe joining technology – the push-and-twist-type connector. Brought to market by companies like Shark Bite, John Guest, Blue Hawk, Elkhart, Cash Acme and others, push-and-twist type connectors allow leak-free connections to be made quickly in tight areas or in situations like new construction in which the plumbing needs to go in fast.
The way all of these connectors work are fairly simple. Imagine one of the old finger puzzles you may have seen or had when you were a kid. You put one finger (pipe) in one end, another finger (pipe) in the other end then, much to your dismay, the harder you pull your fingers apart, the harder the basketweave on the finger puzzle tightens to hold your fingers together. You can only escape if you know the simple little trick. [No spoilers here.—Ed.]
Push-and-twist connectors, whether used to join copper to copper, copper to PEX or whatever to whatever, all work in basically the same way – a series of metal spurs inside the fitting tightly grip the clean, deburred and squared-off pipe while an O-ring, usually made of neoprene, creates a watertight seal. One benefit of using the push-and-twist type fitting is the pipes don’t have to be assembled in their final position as with soldering. Push-and-twist connections can be assembled and then rotated into position afterwards. Need to disassemble the system for some reason? No problem, just use each manufacturer’s simple little trick and you’re ready to reconfigure ‘till your heart’s content.
We’ve already mentioned speed, flexibility and the absence of fire when using push-and-twist type connectors. There are other benefits, as well. For example, pipes don’t have to be perfectly dry when using them as compared to soldering or using glues. Push-and-twist fittings are available in a wide variety of sizes and materials; just about every piping type has a push-and-twist- type fitting designed to be used with it. And, as mentioned before, they’re easily removed if you’re using them in a temporary situation.
As easy as push-and-twist fittings are to use there are some things to keep in mind when you’re using them to whip together a project. First, as mentioned before, the pipes to be joined don’t have to be perfectly dry, but it’s a swell idea to make square cuts with a pipe cutter or tube shears for plastic and deburr the cuts inside and out to prevent damaging the neoprene O-ring in the fitting.
Before you buy 50 or 60 fittings to complete your project, make sure the ones you’re buying are appropriate for the piping materials you’re using as well as the system in which they’re being installed. Don’t waste money and time on the wrong stuff. Read the labels and follow your manufacturer’s instructions to the letter.
The thing with push-and-twist connections is the pipe must be pushed a certain distance inside the fitting before there’s any hope of it working properly. Measure carefully, mark your pipe and make sure it’s seated according to the manufacturers’ instructions before proceeding. Pressure test the system before putting it into service. At least one manufacturer recommends testing new systems with air.
Another tip is, if you’re using a mix of soldered joints and push-and-twist-type fittings on the same system, to go ahead and do your soldering first. This will prevent the possibility of excess heat in the pipe from damaging the neoprene O-ring in the fitting, thus creating a potential leak.
Get your manufacturer’s removal tool, if applicable. You’re going to need it if your system assembly is temporary. You’re going to want to make certain your truck has a removal tool as part of its inventory, even if you’ve installed a bunch of permanent systems. You never know when you’re going to have to get in there and make some room for something else. Being able to remove and re-use the pipe joinery is a big plus.