Valves in Plumbing


There are several plumbing valves used in plumbing in a home or place of work, with their general purpose being to control the flow of water.  Some valves are made from plastic and some are made from metal.  Whichever material they are made from, overtime usage can cause wear and they can fail over time.  If your valve is broken, with some adjustments your valve can be repaired, although for how long cannot be guaranteed.  If you are looking for a long-term fix following a valve problem, the valve should be replaced with a new valve by one of our experienced plumbers.


Ball Valves

Ball valves consist of a ball with a hole in it (the size of the pipe) and it rotates via pressure on its lever to either line up to the hole in the pipe and let water through; to not line up with the hole and therefore not let water through; or to line up partly to let some water through but not a full-flow.   A typical use of this is the one in the toilet which is controlled by you when you flush the lever's handle and let full flow of water through to flush away the toilet waste.


Gate Valves

Gate valves (not to be confused with Stopcocks) control water flow by raising or lowering the gate, which is generally a piece of metal. There is a wheel or knob at the top of a gate valve that controls the height of the gate - this, in turn, affects the flow of water.  On sight, the wheel doesn't provide any indication of whether the valve is fully open, fully closed or at some point in between.  Gate valves arent generally used to adjust the flow, they are used mainly for the on/off function. Gate Valves can get stuck - if this happens we recommend replacing the gate valve as opposed to dismantling and repairing old maybe corroded parts.


Diaphragm Valve

A diaphragm valve is similar to a gate valve in that there is a wheel or knob that moves an element in the valve fitting, which limits the flow of water. In a diaphragm valve, the element is not a gate but a diaphragm that settles down over a saddle, thus stopping water flow.  Diaphragm valves are generally used in stop valves and in boilers.


Pressure Reducing Valves

A Pressure reducing valve is almost self explanatory in its name in that water is let in to the valve at an expected higher pressure, than it needs to be outlet at.  The PRV as it is commonly abbreviated to reduces the pressure before letting the water out at the other side of the valve.

Pressure Reducing Valves should not be fitted by an inexperienced person or DIY'er as there are several rules that should be adhered to for the safety reasons, including sufficient straight pipework run

Pressure reducing valves are typically much more expensive than the aforementioned valves, generally due to their more complex composition, which would normally include an analogue gauge.

If you have PRVs installed and you notice water hammering of any type, more water pressure, less water pressure, or other inconsistencies in the water pressure it MAY be an indication of a PRV not working properly.  To avoid emergency call outs, we recommend a routine call out to check your water pressure approximately  once a year.

Thermostatic Radiator Valves

A thermostatic radiator valve (or TRV) is a valve fitted to central heating radiators.  Part L Building Regulations recommend that on all new central heating system installations a TRV be installed on all radiators, except in the room with the thermostat.  It also recommends that on new boiler fits, a TRV be installed in at least every bedroom (unless that room has been fitted with the thermostat).

A TRV's main job is to reduce to CO2 emissions to the environment & to save on energy consumption, which creates lower bills.

TRVs can be susceptible to leaks or seepage from the joints and the head vents can get clogged by dust and other objects which reduces the air flow within the valve.  Valves can also stick closed or partially open when the small pin controlling the valve moves isn't moving as freely up and down against it's spring as it should be.  If you have a battery operated TRV system, it is an easy DIY job to replace the batteries, but if you are not one for DIY, wwe would be happy to send one of our experienced engineers to do this and any other work you need doing at our affordable half-hourly rate.

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