The Difference Between A 'Type A Drain Cock Valve' And A 'Type B Drain Cock Calve'

A Drain Cock Valve, also known as an MT cock valve, adds a useful drain point to a pipe or heating system. This valve allows the pipe run to be emptied or drained. They are used within compressed air systems. For example, where liquid, gas, or slurry needs to be drained out.

Type A drain cock valves have a gland that prevents water loss when the valve is in use. Whereas, type B drain cock valves do not have this efficient feature. Therefore, type B valves are better suited to households in which a little water loss is not a concern.

It is important to consider that if the valve is being used indoors, type A is probably the best option. This is because if you choose to use type B, the water will run down the threads and leak onto the floor.

It’s also a good idea to check the colour of the water as you drain the system out. If the water is a dirty grey shade, this is expected and is said to be normal. If the water is a darker black colour, this could be a sign of sludge in the system. We stock our own ‘Plumbco’ Sludge & Flux Remover to stop deposits of silt and sludge content in central heating systems.

If the water is a rusty brown or orange colour, this is a sign of corrosion in the system. We also stock ‘Plumbco’ Corrosion Inhibitor, which has a triple blend of corrosion inhibitors. This inhibitor is specific for steel, aluminum, copper, their alloys and most materials found in heating systems.

We have a selection of quality Drain Off Cock Valves available here at Plumbco-online. Each can be used on hot and cold water systems and include an internal washer made from EPDM rubber.