The reason for the isolator valve is really quite simple. If a tap is leaking water or even just a slight drip, this valve will stop the supply of water to the tap so that it can be repaired. It saves the complete system from being isolated. The valve is made with an internal ball bearing, that has a hole drilled through it. As the ball is rotated in line with the pipe it will allow a flow through the hole and when turned again at right angles to the pipe it will stop the flow. It is low maintenance with few parts. To operate this you can use a screwdriver. There is a groove fitted in the pipe which can be turned either on (in line) or off (at 90° to the pipe). Vauxhall Plumbers fit all types of isolator valves. This valve can also be operated with a lever, which is called a ‘lever’ valve. The lever makes it much easier to operate. These valves are useful and hard working, but not pretty to look at, so are nearly always fitted on pipes in cupboards or in a loft. The lever valve is known as a ‘full bore’ lever valve as it has a hole drilled in the internal ball bearing, but this time the hole is the same diameter as the pipe. These are fitted in showers where you need a strong and constant flow of water. They are also available in compression and push-fit types, the latter often being made completely of plastic. A Vauxhall Plumber is experienced with valves. When plastic is used the groove for the screwdriver is often replaced with a short handle. Sometimes you may come across this type of valve as a push-fit type with the groove made from plastic but since the groove can wear due to the constant use of the screwdriver for adjustment it is probably a good idea not to use this type.