Combination Valve.Many areas of plumbing require a number of valves to control the water. The most common uses a filter to clean the water of debris, a check valve to ensure the water only flows one way and a pressure-reducing valve to control water pressure. So rather than use three valves, this combines the actions in one unit. Lambeth Plumbers fit this valve.Double Check Valve.A check valve is used to ensure that water can only run through a pipe in one direction. If the dirty water tries to come back and the first check valve fails then the second will stop the flow.Drain Auger.This a wire that is passed down a drain and twisted in an attempt to clear a blockage.Elbow Joint.This a plumbing fitting that allows the direction of a pipe to change by 90 degrees. A Lambeth Plumber uses joints.Expansion Vessel.When water heats it will expand. This tank is used to contain the expanded water. It is often called the feed and expansion tank as it fills two roles, feeding fresh water into the system and also allowing hot water to expand safely.Gas Safe Register.The organization that took over from CORGI and is responsible for gas safety in the UK, a plumber needs to be gas safe registered.Hose Union Bib Tap.The outside garden tap is one of these in that it has a spout to which you can connect a hose and the tap iself screwed onto a back plate on the wall.Immersion Heater.Effectively a kettle element that fits inside a hot water cylinder and heats up electrically.Machine bend.This is where you bend a pipe rather than use a fitting. A machine called a tube bender makes the bend, and this results in a much gentler bend that will not restrict the flow of water as much as a fitting and is less likely to leak.