Isolating Valve – 15mm – Contractors

A 15mm isolating valve is one of those fittings you reach for constantly on a plumbing job. Whether you’re fitting a new basin tap, connecting a washing machine, or giving yourself a sensible isolation point on a new run of pipe, these are the workhorses of domestic and light commercial plumbing. Quarter-turn operation means you can isolate a supply in seconds without hunting for the stopcock under the kitchen sink.

This is a contractors-grade valve, which means it’s built for the kind of volume use that comes with managing multiple properties or running through a new build. At this price point, buying in quantity makes sense. Keep a stock in the van and you’ll never find yourself on a call-out wishing you’d grabbed a few more before leaving the yard.

Where the 15mm Isolating Valve Gets Used

The most common application is isolation before tap connectors, under basins and sinks, behind toilet cisterns, and at dishwasher or washing machine feed points. Anywhere you want to be able to isolate without draining the circuit is where these go. They’re also useful on central heating systems for isolating individual radiators when a valve change needs doing without a full drain-down.

The 15mm size is the standard for most domestic cold and hot supply pipework in the UK, so compatibility with push-fit, compression, or soldered connections is easy to achieve with the right fittings either side. The valve body itself accepts standard compression fittings on both ends, making it straightforward to drop in on an existing copper run.

At under a pound each, there’s no reason not to have a dozen on the van. One missing isolating valve on a job can hold everything up longer than it should.