Check Valve:This is a valve that only allows water to flow through it in only one direction.Combination Valve:Some Areas in plumbing need a number of valves for controlling the water. A very common example is a filter to clear water of debris, a check valve to make sure the water flows one way and a pressure-reducer valve keeping the water pressure under control. So rather than using three individual devices, the functions are carried out by this one valve.Compression Fittings:Fittings that form a sound watertight seal through compression of a ring made of brass or copper between pipework and a fitting. A Chislehurst Plumber carries compression fittings.Condensate Pipework:Most modern boilers will cool the flue gases down very much that they will condense back into water, the condensate pipework will take the condensate away and feed it to the houses waste pipework.Double Check Valve:The ordinary check valve is fitted to make sure that the water will only flow one way through a pipe. Should any dirty water try and flow back up and through the pipe in an opposite direction, then a double check valve is used, so that if the first fails, the second will stop the water flow.End Feed Fittings:The cheapest form of plumbing fitting, which applies solder to the end of a fitting and lets it run inside to make a watertight seal.ABS:Acrylonitrile butadiene styrene. A plastic commonly employed in the plumbing trade for use as waste pipework. Not very good for outside work. Chislehurst Plumbers use ABS.Bottle Trap:The bottle trap is really a U-bend that uses a trapped volume of water to stop all the horrible smells returning from waste pipes.Box Spanner:A metal cylinder shaped to cover and fit a certain sized nut. This is a handy tool when access to a nut is limited.