A guide to repairing leaking pipes or frozen water lines with a quick and easy method by using a Dresser coupling.
Some plumbing leaks don’t require extensive cutting, removal, and preparation to repair the piping. Frozen pipes are of particular concern as there can split the pipe in one small area and it may not be possible to shut down the system to solder a new piece into place. On this note, Dresser couplings are a type of repair coupling used to splice water supply or drain lines. They can be used on galvanized, PVC, and ABS drainage lines, copper water lines, PVC and CPVC water lines, or galvanized water lines.
If a water line freezes and breaks, you may not be able to repair it with a brass compression fitting or a fitting from the same material as the pipe. This is where a Dresser coupling can be very useful. Sometimes the threads on old galvanized water lines become so corroded that it is not feasible to rethread the pipe. You may be able to use a Dresser coupling to repair the leak as long as the pipe has not begun to rot away.
Dresser couplings have been in use for over one hundred years and there are specialty couplings for low or high pressure, water lines, drain lines, air systems, steam, waste water, and others. Small couplings use a compression fitting, while larger couplings utilize high strength bolts or bands.
Dresser couplings come in two types, galvanized and plastic. The design consists of a sleeve with an inside diameter to allow it to slide over various sizes of pipe. The sleeve is threaded on both ends and comes with two threaded nuts. There is a molded rubber compression ring inside a groove of each nut. One edge of each rubber ring is beveled to allow it to compress fully when tightening and these bevels need to be installed toward the center of the sleeve to match the bevel inside the end of the sleeve. Inside the galvanized Dresser coupling nuts there is a metal friction ring. You must use this ring when you assemble the Dresser coupling during a repair otherwise your repair is almost certain to leak.
Straight Galvanized Dresser Coupling
90 Degree Elbow Dresser Coupling
Tee Dresser Coupling
Install the Fitting
To use a Dresser coupling, just cut the pipe where you need to repair it with a hacksaw or tubing cutter, slide the nut and rubber compression ring over the end of the pipe in that order and push the nut and rubber compression ring down the pipe at least the length of the sleeve. If the pipe is split over a length of the pipe, as in the case of a frozen pipe, cut out a section of pipe and replace with a new piece of pipe that is the same size and material. You will then need two Dresser couplings to secure the new pipe in place.
Slide the sleeve over that same end of the pipe. Slide the second nut and compression ring respectively over the opposite end of the pipe you cut.
Center the coupling sleeve over the cut you made in the pipe. Carefully work one rubber compression ring toward the coupling until it seats inside the sleeve. Make certain it seats uniformly around the entire ring. Note: This is similar to a PVC drain line gasket found under sinks.
Slide the nut up in place and hand tighten it. Do the same for the second rubber compression ring and nut. Once both nuts are hand tight, using a pipe wrench or pump pliers to hold the sleeve, use a second wrench to tighten each nut. If the Dresser coupling is plastic use two pairs of pump pliers instead of pipe wrenches and do not over tighten the nuts or they will crack. You can use pipe wrenches on the nuts if they are galvanized.
Dresser Coupling on Black Iron Fire Sprinkler System Line
Dresser couplings cannot withstand movement along the length of the coupling so the pipe to be repaired must be secured in a way to prevent movement that could potentially pull the pipe out of the coupling. This is especially important in repairs on vertical pipes as the weight of an unsecured pipe can cause it to work free over time. If it is not possible to secure the piping, select another type of fitting or use a permanent repair.
Dresser couplings are widely used due to the fact that they will work on slightly misaligned pipes and can be removed and reused to access other plumbing components that may need to be repaired, replaced, or cleaned on occasion.
If the Dresser coupling is reused, inspect the rubber gasket to make sure it is still flexible and in not cracked or deformed.
Dresser is the company that developed the coupling but they are also made by different manufacturers.