Plumbing 101- Cutting Pipe and the Proper Plumbing Tools to Use
Measure Twice Cut Once
The proper measuring of plumbing pipe is probably one of the most important skills a plumbing professional can master and it’s also one of the things homeowners stumble on when trying to perform their own repairs. Believe us when we say there are plenty of plumbing professionals out there that we call “try plumbers”, they put the pipe and fittings together loosely stick it up in the air to try it out, then take it down to cut it. It’s time consuming and ridiculous especially when you can follow a few simple steps to ensure a proper measurement.
Piping is Piping, Fittings are Fittings
When measuring a piece of pipe for a repair or install you’re most likely going to have fittings involved. It doesn’t matter whether you’re dealing with PVC, copper, cast iron or galvanized the measurement process is the same.
Always Remember Center to Center Dimension
The first thing you must know is the measurement you need from the center of one fitting to the center of the other fitting. It makes no difference if the dimension is from the center of a 90 degree ell to a tee or the center from one 90 to another 90.
The next most important thing to find out is the fitting takeoff. The fitting takeoff is the dimension from the center of the fitting to the back of the cup, hub or threads depending on the material you are working with. Please see the diagrams below for examples of fitting takeoffs for various types of materials.
Believe it or not that is all you need. So what do you do with the dimensions that you have? You take the A dimension (Center to Center) and subtract the B dimensions (Fitting Takeoff) and that leaves you with the C dimension the end to end measurement for the pipe. It’s that simple and it works for every type of material. If you are working with no-hub pipe or welded fittings your fitting takeoff will be from the center of the fitting to the end of the fitting because there are no threads or hubs to worry about.
Please see the diagram below for a visual explanation of the terms and concepts above.
So now that you know how to measure and cut a piece of pipe correctly here is a brief description of the proper tools to use to get the perfect cut.