1. Common Requirements
Taps and Valves

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. Showers, testing and fault finding

14. 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
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15. Barry Spick

16. 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
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17. 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

18. 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

19. 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

20. 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

21. 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

22. Pipe run in preferred position around a bath
Miscellaneous
Pipe in sleeve through wall
Pipe run in preferred position around a bath
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23. End of Presentation
Barry Spick