Quarter turn taps - Taps which can be turned fully on or fully off by rotating the handle through just 90 degrees. May use ceramic disc valves or fast-action washer valves.


Rainwater harvesting - The gathering, or accumulating and storing, of rainwater.

Rim- Water, from the flushing cistern, is made to flow around the WC bowl using different designs of flush rim found at the top of the WC bowl.

  • Box rim is formed from what looks like a tube with slots and holes created in its underside. Water from the cistern is guided around the rim and allowed to jet into the WC bowl through the holes and slots. In this way water is controlled to give the best flush performance.
  • Open rim looks like an inverted U-shape. Water from the cistern is guided around the rim under its own rate of flow. 
  • Rimless These WCs have no U or slotted-tube arrangement. Water floods into the WC bowl from small jets created in the ceramic. The shape of the top of bowl (sometimes a beveled edge) prevents water from overflowing.

Riser rail - See slide rail

Roll top - The traditional shape to the top of a freestanding cast iron bath. Roll tops are also available in plastics materials.

Rising Spray for a bidet | Sometimes called Ascending Spray - The water outlet sometimes found in the bowl of a bidet. Produces a small fountain of warm water.


Sequential control - A single control knob on the shower mixer control initiates flow at a cold setting. Then progressive rotation of the control increases the temperature.

Service Valve - A valve for shutting off flow of water in a pipe connected to a water fitting in order to allow maintenance.

Shower Head - A device designed to create the spray pattern on a shower.

Shower bath - A special shape of bath which has a bull nose or bulbous tap end (sometimes called keyhole shaped) which gives extra space to stand in when the bath is used as a shower. Usually available in right handed or left handed options. 

Shower panel or tower - A pre-assembled shower unit consisting of one or more jets. Requires minimal installation. Wall mounted. May have manual or thermostatic controls.

Shower hose - A flexible hose connection between the shower mixer body and the shower head.

Single lever control - A single lever performs two functions. Moving the control up and down regulates flow. Moving the lever to left and right adjusts the temperature.

Single lever taps - A single monobloc tap with a lever handle that controls both water flow and temperature.

Slide rail - A vertical rail fixed to one wall inside the shower enclosure. The shower hose and shower head are fixed to this. The height of the shower head is usually adjustable by sliding up or down on this rail.

Spray head / Shower head - The outlet for the water spray. The design of the jets in a spray head can vary to give differing spray patterns and varying shower experience.

Storage cylinder - The hot water storage cylinder supplies hot water for domestic use and is heated by the boiler or electric immersion heater.

Static Pressure or Standing Pressure - The water pressure at a fitting with no flow taking place.

Strainer or Filter - A screen or mesh which prevents debris from entering a water fitting. 

Siphon - This is the traditional lever-operated device which draws water from a cistern to create the water cascade which flushes a WC.