Glossary

We want to keep things as clear as possible and we therefore hope you find the following useful.

B.E.A.B.

The British Electrotechnical Approvals Board.

Bar

A unit of measurement of water pressure approximately equivalent to a column of water 10m high or 14.5 lbf/in (or 100 kPa) per bar.

Body Jets

Wall mounted sprays usually installed in multiples.

Built-in

A valve installed where the body is recessed in the wall.

Cold Water Storage Cistern

Fixed container for holding water at atmospheric pressure usually used for providing a feed to a vented domestic hot water cylinder. It can also be used to provide a vented cold supply to terminal fittings.

Diverter

A fitting used to control the direction of water to various outlets

Double Pole Switch

An electrical switching device in which the continuity of both the mains live and neutral is broken upon the action of the switch giving a contact separation of at least 3mm. The earth always remains connected.

Element

A component used in an instantaneous electric shower to heat the water.

Exposed

A shower that is mounted onto the finished wall surface and is not recessed into the wall.

Fixed Shower Head

An over head fixed height shower head.

Flow

The volume of water moving through a given point, normally expressed in litres per minute, gallons per hour or metres cubed.

Flow Limiter

A device with moving parts which responds to variable inlet pressures to control flow at a reasonably constant rate. These are subdivided into two types: (a) Fixed - manufactured in a range of predetermined flow rate settings. (b) Variable - manually adjustable to provide different flow rate settings.

Handset

A shower head attached to a flexible shower hose also termed a shower handset.

Hot Water Cylinder

Means a cylindrical closed vessel capable of containing water under pressure greater than atmospheric.

Impeller

The internal part of the pump that is driven by the motor, and is used to pressurise the water.

Instantaneous Electric Shower

A shower that electrically heats the water whilst the water is passing through it.

Integrated Power Showers

An all in one power shower features a pump and integrated shower control and requires a low pressure cistern fed supply of stored hot and cold water.

M.C.B.

A Miniature Circuit Breaker is an electrical circuit protection device used as an alternative to rewireable and cartridge type fuses. It trips out when too much current flows in the circuit, typically on fault conditions. Do not confuse with R.C.D.

Manual Mixing Valve

A device which does not compensate for variations in the temperature or pressure of the incoming water supplies and needs to be adjusted manually.

Mixer Shower

The mixer valve and fittings.

Open Outlet Flow Rate

Maximum potential flow rate from mixing valve without shower fittings attached.

Pressure Compensating

A pressure balancing compensatory shower mixer valve designed to maintain a constant shower temperature under variable inlet pressures but maintained inlet temperatures.

Pressure Relief Device

Safety device fitted to prevent excessive pressure building up within an electric shower heater.

R.C.D.

A Residual Current Device is an accurate electrical balance that measures the electrical loading on the outgoing live and return neutral conductors. If any current leakage exceeds the trip value under a fault condition it turns off the power supply. An R.C.D. is sometimes known as E.L.C.B., R.C.C.B. or trip switch. Do not confuse with M.C.B.

Running Pressure

The water pressure in the pipework to a fitting whilst flow is taking place.

Shower Head

Any device designed to produce a spray pattern.

Shower Hose

A flexible pipe that connects between the shower head and the shower control.

Shower Tower

A pre – assembled shower unit consisting of one or more jets, requiring minimal installation. Wall mounted, these units usually come with a variety of options ranging from thermostatic or manual mixing, with fixed overhead, flexible hand showers and body showers, which can be manually or electronically controlled.

Stabilised

A shower control that reacts to changes in water pressure in order to maintain a relatively constant flow and temperature at the shower outlet.

Static Pressure

The water pressure existing at a fitting when no flow is taking place.

Thermostatic Mixing Valve

A device to compensate for variations in the temperature and, or pressure of the incoming water supplies, to maintain a selected blend temperature.