MT Drain Off Cock 15mm

The MT Drain Off Cock is a small valve fitted at a low point in pipework so the system can be drained. It has a hose outlet, and the spindle is turned to open or close it.

Where to fit an MT Drain Off Cock

Every heating system and most water systems need a way to empty them. Fit one at the lowest point of each section, such as the bottom of a riser, under a cylinder or at the foot of a heating drop. When work is needed, push a hose on, run it outside and open the cock. Without one, you end up cutting pipes and flooding floors.

• Size: 15mm x 15mm
• Hose outlet for draining
• Spindle turned with a key or spanner
• For heating and water pipework

Set the outlet at an angle that leaves room for a hose. Once fitted, make sure it is fully closed, then test for weeps. When draining, open a vent or tap at the top of the system to let air in, or the water will barely trickle. Close it firmly but gently after use. More valves are in Valves and Control Devices.

Drain cocks in Glasgow

Plumb Parts, 555 South Street, Glasgow G14 0QX. Our counter hours are Monday to Friday 8am to 5pm and Saturday and Sunday 8am to 1pm. Order online if easier.

Specification

• Sizes: 15mm x 15mm
• Suitable for: Drain points at low points on heating and water pipework

Common Questions

Where should I fit a drain off cock?

At the lowest points of the system, so all the water can run out. Heating systems often need one at each low loop.

How do I open a drain off cock?

Push a hose onto the outlet, then turn the spindle with a drain key or small spanner. Close it again firmly when the system is empty.

Why does my drain cock drip?

Grit on the seat or a worn washer stops it shutting fully. A blank cap screwed onto the hose union helps stop a slow drip.