How To Measure a Tap Valve Spline

If you need to replace a broken tap valve or tap cartridge, then you will need to count the number of spline on the old valve, so that you know which size to buy to replace it. Many people don’t know which part of a tap valve is the spline, so we wanted to explain this.

The spline is the tiny teeth on the end of the tap valve/cartridge, and these determine if they fit into the tap body. The most widely used tap valves often have 20 or 24 teeth, however they can vary from 18, 28, 30, 32, 36, 38 to as large as 50 teeth.

It can be tricky to count the teeth as they are quite small, but one tip is to make a mark on one of the teeth with a pen and count round, or take a photo and enlarge it to help count.

The image below will help you identify the parts a tap valve and help you work out which size you need to buy to replace it.