Glossary of Plumbers Terms

Rising Mains:

The name for the cold water pipe that runs from the water supplier’s stopcock to feed water (under pressure) to a kitchen tap and also cold water storage tank in a loft. This needs to be the first valve to be closed in an emergency.

PTFE Tape:

A thin, ribbon-like very soft plastic material used for sealing threaded fittings. The tape is wrapped around the thread before the joint is tightened up so that the tape fills the ‘V’ section parts of the thread. Most professional plumbers like to use the tried and tested method of wiping the thread with a mastic made from putty, and then finishing by winding over a thread of hemp fibre. A Power Flush London service use this tape.

Fused Connection Unit:

This has the function of allowing a junction between a high rated cable and a low rated cable or flex, using a fuse that will blow to prevent the smaller cable being overloaded and burning out.

Alignment:

The term for setting one part on or against another, such as a socket on a wall, with the help of a measure and spirit level in order to obtain a good line and fit. Power Flushing London services carry out this action.

Airlock:

The term ‘airlock’ refers to a trapped pocket of air in pipework which stops the water supply to a tap. The possible cure is to take a length of garden hose, place it over the blocked tap and the kitchen cold water tap and turn them both on to clear.

A Cistern:

This is another name for a water storage vessel. For example, both the tank on the WC and the cold-water storage vessel in the loft can be called cisterns.

A Draincock:

This is the lowest tap in an appliance (like a boiler or a radiator) or system, from which water could be drained. One way to drain a system is to simply place a garden hose on the drain cock and run the other end of the hose into the garden or outside drain and then turn on the tap.
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