Common Requirements Taps and Valves

Taps and Valves Applies equally to Hot and Cold systems They are used to isolate supplies Water regs require that fittings are: Suitable for their purpose Made of corrosion resistant materials Have sufficient strength to resist normal and surge pressure Capable of working at appropriate temperatures Easily accessible to renew seals and washers Barry Spick

Taps and valves Cont’d Taps and fittings for both hot and cold water should conform to BS 1010 parts 1 and 2 BS 1552 BS 5433 Taps and valves are usually made of brass Pressings Castings Chrome plating where appearance counts Chrome plating also improves ease of cleaning Plastic taps and valves are also available Barry Spick

Position of Stopvalves and servicing valves in buildings As far as is reasonably practible: Be located inside the building Be easily accessible Located above floor level As near to point of entry of supply into building Installed so that its closure will prevent the supply of water to any point within the premises. Servicing valves Inlets to all float-operated valves,cisterns,washing & dishwashing machines, water heaters,water softeners and other similar appliances should be fitted with a servicing valve Valve should be fitted as close as possible to inlet of device. May be screwdown or spherical type Barry Spick

Stop Valve Between incoming mains and rising main The one shown is a: Screw down type Made to BS 1010 They are usually located on high pressure systems How does it work? Washer and jumper fit into threaded part of spindle Is raised and lowered by turning the crutch head When lowered to maximum the washer sits on the seating Closes the flow of water Between incoming mains and rising main Used for the main isolation valve Can be used as service valve to cwsc cistern, F & E cistern Barry Spick

Gate Valve Sometimes referred to as Full way Gate Valves When its open there is no restriction Normally fitted with a wheel head attached to a spindle When the head is turned clockwise the gate is lowered Closes the flow of water Normally used on low pressure systems Used on the cold feed from CWSC Also cold distribution pipe Barry Spick

Spherical Plug Valves Maintenance: Quarter turn valve can be used as a service valve Normally fitted with nut and olive Also have internal threads for use with LCS Where can they be used? For washing machines Service valve for cwsc Used on single point water heaters To isolate float operated valve on toilet cistern Maintenance: What should you do if the valve is defective e.g. the centre is leaking or passing Replace the valve, why? Cannot be repaired Barry Spick

Draw off taps Can you name other types of taps? Supataps Bib taps Pillar taps Rising Spindle Non-rising spindle High neck pillar taps ‘used on sinks’ Fitted to sink with top hat washer Tap assembly Supataps Barry Spick

Maintenance Supatap Rising Spindle tap Can be re-washered Re-seated Re-pack gland Non-rising spindle Re-washered CANNOT be re-seated Re-new tap May require circlip pliers for gland Supatap Change washer Barry Spick

Quarter turn taps Ceramic disc quarter turn taps Maintenance requirements Circlip holds workings in place Cannot be re-seated Can change ceramic discs Need to obtain new head from manufacturer Hot and cold internals are handed for H on left C on right Barry Spick

Mixer taps Maintenance: Same as previous types of taps Many designs on the market All have the same purpose To have hot and cold supply coming out of one spout Two designs: Single flow outlet Water mixes in the body of the tap If water pressures not balanced then tap will not perform as it should Twin flow outlet Waters mix at end of spout outlet Does not matter if water pressures not balanced Maintenance: Same as previous types of taps Barry Spick

Drain off Tap Made to BS 2879 Has a ribbed outlet for a hose to be fitted Fitted at lowest point of system Some fitted with a lockshield head Special key required to open valve Can be fitted into stop valve with special connection Maintenance: Washer liable to stick to seating Re-washer Barry Spick

Showers, testing and fault finding

Showers Showers can be fed by: Storage Mains pressure Boosted supply Water regs require that: Backflow cannot occur Done by installing double check valve Ensure that the shower valve is thermostatic Shower with check valve installed Barry Spick

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Storage fed 1m Minimum Cold feed to DHW cylinder Above height of shower cold feed Alternative position for connection 1m Minimum Flange or specially produced cylinder Shower mixer Dedicated pipework for mixer Barry Spick

Noise in systems Noise in systems is usually caused by vibration Can be categorised as: Water hammer Flow noise Expansion noise Expansion noise is usually caused by the expansion and contraction of pipework as it passes through holes etc that have been cut in joists etc Water hammer can be caused in several ways Pipes not clipped sufficiently Worn washers on taps and valves Velocity of water Flow noise Heard through the float valve as the cistern is filling Cures can be by installing a pressure reducing valve if velocity is over 3m/s Barry Spick

Soundness Testing Soundness testing is essential if you want to leave a system sound BS6700 provides the standards for testing Procedures Visual inspections Testing for leaks Pressure testing Final checks Visual Inspection Includes making sure that all pipework and fittings are thoroughly inspected to make sure: They’re fully supported, including cisterns and cylinders They’re free from jointing compound and flux All connections are tight All terminal valves are closed In line valves are closed to allow stage filling Cistern is free from swarf and clean Barry Spick

Procedure for testing rigid pipe Seal all open ends Testing for leaks Slowly turn on the stop tap to the rising main Slowly fill the system in stages to the various service valves Open service valves to appliances Check for leaks Make sure cistern levels are correct Make sure system is vented prior to pressure testing BS6700 has separate procedures for testing rigid and plastic pipes Procedure for testing rigid pipe Seal all open ends Fill the system and stand for 30min Pressurise system using hydraulic testing to 11/2 times working pressure Leave to stand for 1 hour Check for visible leaks If sound the test is satisfactory If not sound repair leaks and re-test Barry Spick

Check the pressure after a further 30 mins BS6700 shows two test procedures for plastic pipes. Procedures A and B Test B Apply test pressure (1.5 times max working press) by pumping for a period of 30 mins Inspect for leakage Check the pressure after a further 30 mins If the drop is less than 0.6bar System has no obvious leakage Visually check and monitor for a further 120mins if the system has dropped less than 0.2bar The test is satisfactory Test A Apply test pressure (1.5 times max working press) by pumping for a period of 30 mins Inspect for leakage Reduce pressure by bleeding water from system to 0.5 times working press Close bleed valve Visually check and monitor for 90 minutes If pressure remains at or above 0.5 times working pressure Test is satisfactory Barry Spick

Installation of Pipework Accessibility Water regs require That water pipes and fittings are easy to get at in order to carry out inspection and repair Customers and installers are not keen to see exposed pipes. Tendency to hide under floors and in walls BS6700 gives recommendations about the accessibility of pipes and water fittings Here are a few Barry Spick

Pipe run in preferred position around a bath Miscellaneous Pipe in sleeve through wall Pipe run in preferred position around a bath Barry Spick

End of Presentation Barry Spick