‘Hydraulic’Urinal Flush Control Valve

Valve Identification and Application

There are three valves in the 'hydraulic' range; each is suitable for
a specific supply pressure.

The STD and LP can be fitted with the optional Hygiene Flush (HF) attachment to ensure a minimum flush approximately at least once every 24 hours where washroom use is irregular or the building is subject to long periods of non-occupancy. The HF attachment can be supplied factory-fitted or fitted at a later date if necessary.

Valve Operation

• The STD, LP and HSLP valves are 'normally closed'. They are opened by changes in water supply pressure when using facilities such as the hand basin cold water tap or flushing the W.C.
• Once activated, water will pass through to the urinal cistern until the valve automatically closes. After a series of activations the cistern will contain sufficient water for the auto-flush siphon to operate and flush the urinal/s.
• If properly maintained the auto-flush cistern will continue to operate in this manner during periods of occupancy providing flushing activity when washroom facilities are in use.
• Valves remain closed during non-occupancy preventing wasteful flushing unless the HF attachment is fitted.
• Valve operation is automatic and requires no action by washroom users or maintenance staff.

Valve Adjustment

• During normal operation the flushing frequency is dependant on the use of cold water services and the quantity of water passing through the valve each time it is activated.
• The length of time that the valve remains open can be changed by using the red Allen key supplied (or a 2BA socket) in the socket head of the restrictor screw found at the side of the valve.
• Clockwise rotation increases the open time, giving more water per activation thus increasing flushing frequency and vice versa. This adjustment is best carried out by the installation engineer or authorised maintenance staff.

Valve Life and Warranty

• The life expectancy of a valve varies according to a wide number of factors. These include water pressure, the number of daily activations, quality of the water supply etc.
• Cistermiser valves are warranted against defects in materials and/or workmanship for 3 years from date of manufacture (given by a serial number which can be found on the label).
• If a valve develops a fault after working satisfactorily, see the below troubleshooting or alternatively please contact Cistermiser Technical Services for assistance.

TROUBLESHOOTING

These notes assume that the valve has been working satisfactorily in the past and correctly installed with regards to correct valve selection, location on the supply and the general plumbing arrangement. Before calling Cistermiser customers are strongly advised to take a few minutes to check this guide. This will ensure that they can answer questions which may enable them to solve problems themselves or to enable engineers to solve the problem for them.

Valve appears to be permanently closed

• The commonest cause of valves failing to open is trapped air, either in the valve itself or in the adjacent pipe work, possibly as a result of turning the water off to carry out maintenance work. Trapped air can be vented from the system via the restrictor/adjustment screw as follows: - Turn off the water supply to the valve. - Unscrew the restrictor until the first "o" ring is clear of the body. - Slowly restore the supply until water sprays from the restrictor; this will release any trapped air. - Reduce the supply until almost off: turn the restrictor back in 2 turns below the valve body. - Restore full pressure. Allow a few minutes for the valve to 'charge': it should then activate.
• Valves can also remain open as a result of sediment blocking the inlet filter. To clean the filter, disconnect the valve, scrape away any build-up from the mesh and back-wash the valve (water can flow in the reverse direction). The mesh can be removed with a pair of narrow-nosed pliers. Remember to vent the valve (above) when you have re-connected it.
• The third possibility is scale or other deposits clogging the nozzle/s of the ball-cocks of the W.C. cisterns. This will reduce the pressure drop after flushing the W.C. to the extent that the change cannot be registered by the valve (which could be some distance away). To fix the problem, clean the inlet valve of the W.C. cistern. The position of the restrictor screw on the hydraulic valve should also be checked as over-adjustment either way can affect operation.

Valve appears to be constantly open

• Valve is installed in reverse. Remove the valve and fit with arrow (located at the base of the valve) in the direction of water flow. Water pressure too high for valve: may crush bellows. Purchase a valve suitable for your water pressure.
• If this is an old installation contact Cistermiser for further advice.

Flow through the valve is inadequate

Valve flow is controlled by adjusting the restrictor screw on the valve, which controls the length of time that the valve is open each time it is activated. This is normally set at installation but can be adjusted at any time. The restrictor screw should always be turned at least two full revolutions below the valve body (see "valve appears to be permanently closed"). To allow more water into the cistern each time a tap or WC is used and therefore prompt more frequent urinal flushes, turn the restrictor screw in more revolutions. It is advisable never to turn it more than 2 revolutions in total. A replacement red allen key is available from Cistermiser.A valve can be adjusted so that it fills a cistern in two or even one activation.

Essentially the more frequently urinals or taps are used the more the valve is activated to provide regular topping-up rather than complete cistern filling.Where use of services is infrequent and supply pressure is low the IRC provides more accurate control than a hydraulic valve – FAQ’s

Do not open the valve

• Opening a valve under 3 years old will void the guarantee.
• We do not recommend opening any of the valves.

CHECKLIST

What services are being used to activate the valve?

Since the valve is normally closed, other services are required to activate the valve

Are there any other services on the cold water supply to the urinal cistern such as WC’s or taps?

If not the valve will not activate and should be replaced with a Cistermiser IRC. (Not all services are on a common supply)

Is the valve correct for the supply pressure?

A valve subjected to a lower pressure will not function; a valve subjected to a higher pressure may be damaged

Has the valve been vented and if so where is the restrictor in relation to the body?

Trapped air will cause a malfunction and the restrictor should be recessed by approx. 2mm into the body of the valve, not flush or protruding

Is the supply on a larger diameter pipe than the service to the cistern?

All services including the cistern and valve should be on common 15mm pipe; if the supply is in 22–28mm the ability of the valve to detect pressure change is restricted

How far is the valve away from the ‘take off’ to the other services?

Ideally the valve should be installed within 3 metres of the drawoff point. Distance reduces the ability of the valve to detect pressure change

If there is any restriction on the outlet into the cistern?

Pet cocks are sometimes left on and can cause back pressure on the valve

Is the water supply pressurized or pumped? If not it is advisable to replace the hydraulic valve with an IRC.

(A supply that immediately makes up pressure loss as services are used reduces the capability of the valve)

If the taps are mixer or aerated and if a W.C. is the only other service?

Such taps do not always register a significant drop in supply pressure and may not activate the valve, similarly a W.C.

If the building has been unoccupied for some time or other plumbing work has been done?

Anything, particularly with water involved, should be operated regularly to avoid drying of rubber components etc. Other work may have introduced air into the system or disturbed the valve necessitating re-venting.

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