Transcript
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TREVI PBV SEQUENTIAL PRESSURE BALANCED SHOWER VALVES
INSTALLER After installation pass to user for future reference Installation Instructions A5109 Trevi PBV Built-In A5133 Trevi PBV Exposed
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GENERAL NOTES This installation instruction covers the Trevi ‘Sequential’ Pressure Balancing shower Valve (PBV). These PBV’s are designed to adjust for variations in inlet pressure and will maintain a constant outlet temperature only if the inlet water temperatures remain stable.They do not have a means of sensing water temperature and must not be thought of as thermostatic. Their main use is in systems which provide a relatively stable hot water temperature but where there are likely to be pressure variations in the supplies caused for example by draw-offs elsewhere in the dwelling.
They are particularly suitable for use where the hot water system is based on one of the following: ●
Fully modulating combination boilers
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Fully modulating multi-point gas water heaters
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Unvented mains pressure storage systems
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Mains pressure thermal heat storage systems fitted with blending valves
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Pumped systems
They are not suitable for conventional cistern fed, gravity, hot water systems.
Two versions of the sequential PBV are covered by this installation guide. A5109 Built-in Sequential Pressure Balancing Valve designed to be recessed in the wall. A5133 Exposed Sequential Pressure Balancing Valve designed to be surface mounted with either recessed or exposed pipe work. All models are supplied with separate in-line servicing valves incorporating strainers (Figure 1) which must be positioned in the supply pipes in an accessible position so as to enable the strainers to be cleaned.
Operation These valves are suited to applications where the user may be at risk as the delivered water temperature increases through cold to warm and then hot as the control knob is operated. Both flow rate and temperature selection are controlled by a single knob which is rotated in an anticlockwise direction to operate the fitting. From the off position where the knob lever is at six o’clock the knob is rotated anticlockwise. After a little rotation the water starts to come on, cold at first and as the knob is turned further the cold flow increases. With further anticlockwise movement the water starts to get warm and the temperature
increases progressively with rotation until maximum is achieved when the lever on the knob is pointing to about two o’clock. This valve features a limit stop which can be set to prevent the user turning the control knob to the full hot position. The exposed version incorporates adjustable inlet elbows which can be turned backwards to receive supplies from within the wall. The centres between the inlets are adjustable between 147mm and 155mm. The elbows can also be turned upwards or downwards to connect to falling or rising surface pipework.
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WATER BYELAWS Water Supplies and Water Regulations Requirements Installation practice. Where appropriate, installation must be done in accordance with Water Regulations, Building Regulations and Code of Practice BS 6700. We recommend installation be carried out by someone who is registered with one of the following trade organisations. ●
NAPHMSC National Association of Plumbing, Heating and Mechanical Services Contractors. 02476 470626
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IOP Institute of Plumbing 01708 472791
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SNIPEF Scottish & Northern Ireland Plumbing Employers’ Federation 0131 225 2255
NB Gas appliances can only be installed by a CORGI registered installer.
Water Pressure Mains pressure hot water systems will normally be fed through a Pressure Reducing Valve (PRV). If there is no cold water take off available downstream of the PRV but before the heating appliance it will be necessary to supply cold water to the Pressure Balancing Valve through a separate PRV set at approximately the same pressure as the one supplying the water heater. The temperature of the hot water must not exceed 85ºC but the installer’s attention is drawn to code of practice BS 6700 which recommends that stored hot water should normally never exceed 65ºC. For satisfactory operation of the fitting 60ºC is ideal but it must
be higher than the desired showering temperature; ideally 45ºC is the minimum for correct operation of the fitting. The fitting is to be so installed as to be readily accessible for examination, repair, replacement or operation. (IRN 111) To enable servicing to be carried out easily and to ensure that the mechanism is protected from water borne debris, each fitting is supplied complete with separate in-line isolating valves/ strainers. Figure 1. These should be positioned in the supplies so as to be accessible for servicing after installation.
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BACKFLOW PREVENTION The water regulations published in 1999* take
supply pipe. For this reason it must not be
a new approach to backflow in that they
possible for any flexible shower head to be
look at different categories of risk. The
able to enter any adjacent washbasin, bath or
installer must assess the risk from the various
shower tray unless appropriate protection is
categories of fluid in adjacent appliances
employed. (See Figure 2)
before determining the level of backflow protection required for a particular installa-
The pressure balancing mechanism is fitted
tion. The following diagrams outline the
with single check valves (Figure 13). If it is
protection required in various installations.
desired to allow the handspray to be used
CATEGORY 3 RISK
inside say a bathtub or a basin it is essential
Water in a shower tray, basin or bathtub is
that additional check valves be fitted to the
considered to be a fluid category 3 risk which
inlet on both hot and cold supplies to the PBV.
is a fluid which represents a slight health
Alternatively, an additional check valve should
hazard if it were to find it’s way back into the
be fitted in the valve outlet.
Figure 2 Fluid Category 3 risk *A guide to the Water Supply (Water fittings) Regulations 1999 and the Water Byelaws 2000, Scotland is published by WRAS (Water Regulations Advisory Scheme) Fern Close, Pen-y-Fan Industrial Estate, Oakdale, Newport, NP11 3EH ISBN 0-9539708-0-9.
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BACKFLOW PREVENTION CATEGORY 5 RISK Water in a Sink, WC or Bidet is considered to be a fluid category 5 risk which is a fluid which represents a serious health hazard if it were to find it’s way back into the supply pipe. For this reason it must not be possible for any flexible shower head to be able to enter any adjacent Sink, WC or Bidet. (See Figure 3). If the flexible hose to be fitted could reach into any such vessel, double check valves are not an adequate protection against this risk. Indeed the requirements for the system design are so onerous it is better to consider fitting an overhead shower rather than a flexible.
It will also be seen that this risk could change should the hose be taken out of the restraining device or should a longer replacement hose be fitted at a later date. Installers and householders are strongly advised to take account of these factors when fitting replacement hoses. For pumped applications the pipe supplying the pump must not, in addition, supply an ascending spray bidet.
Figure 3 Fluid Category 5 risk
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HEATING SYSTEMS COMBINATION BOILERS AND INSTANTANEOUS GAS FIRED WATER HEATERS. If the Trevi PBV is being installed with combination boilers or multi-point gas fired water heaters these must be of a fully modulating design. A fully modulating heater is one
where the output of the gas burner is reduced in proportion with the draw-off rate. This produces the reasonably constant hot water temperature which is required for the PBV.
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HEATING SYSTEMS MAINS PRESSURISED THERMAL HEAT STORAGE SYSTEM The thermal heat store system stores hot water in the primary circuit at low pressure. The mains pressure cold water is fed into a heat exchanger coil where it is heated by thermal transfer from the stored hot water. Because the hot water temperature can vary
with the flow rate a blending valve is often used to stabilise the output hot water temperature. When contemplating fitting a Trevi PBV it is essential to ensure that such a blending valve is fitted to the system.
MAINS PRESSURE UNVENTED HOT WATER STORAGE SYSTEM The PBV may be fitted to mains pressurised unvented hot water systems. Where the system does not have a cold water take off downstream of the pressure reducing valve (PRV) a separate PRV, set at the same value, will have to be fitted on the cold supply.
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TECHNICAL DIMENSIONS
Figure 7 A5109 - Built-in Sequential PBV
Figure 8 A5133 - Exposed Sequential PBV
INSTALLATION GUIDE Built-in model The Trevi sequential PBV is delivered ready to be installed with the plaster guard fitted. Attached to the rear of the valve body is a polystyrene moulding which acts as a stabilising bed when the body casting is secured in the wall. The valve should be recessed in the wall and
the depth of the recess should be measured from the finished wall surface to the rear of the polystyrene moulding. There is an adjustment of 20mm in the installation depth from 52.5mm minimum to 72.5mm maximum from the finished wall surface. See Fig 9 The minimum and maximum depths are indicated on the mounting template / plaster guard.
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INSTALLATION GUIDE Connections to the valve bodies are ½” BSP and are marked HOT and COLD on the top of the casting.
Exposed model Decide which configuration of pipe work is to be employed. Adjust centres (147 min & 155 max) of the elbows by screwing them in/out to the desired dimension. Connect the fitting - loosely at this stage as the cover slips may still have to be fitted - to the pipe work. The body is marked hot on the left and cold on the right. Mark the position of holes for fixing screws (32 )
22 52.5 72.5
maximum minimum
Figure 9 Built-in PBV with plaster guard fitted 1.
Chase out the wall for the mixer body and pipe work.
Remove fitting from pipe work and drill and plug the wall. If installing with surface pipe work, fit the elbow cover pipe slips (4) to the pipes . Reconnect the fitting to the supplies. Screw fitting to wall and fit elbow covers ensuring that the lugs on the pipe slips engage behind the cover (7 Figure 11)
2. Remove the plaster guard. 3. Connect the pipe work to the valve body. (Do not make any soldered joints near the valve body and ensure it is installed in vertical and horizontal alignment to the wall surface (Figure 10) and within the build-in depth limits. See Figure 9) 4. Replace the plaster guard and complete the plastering/tiling work 5. Remove the plaster guard when the plaster work is dry 6. Fit the Cover plate and trim
Figure 10
Figure 11 Fitting the cover slip
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INSTALLATION GUIDE
Flushing operation
To adjust the limit stop proceed as follows:
The pipes must be flushed before any water is permitted to pass through the PBV
1.
1.
Ensure the flow control on the PBV is turned fully off (clockwise).
2. Gently prise up the red limit stop and pull off.
2. Turn the servicing valve to the off position (1).
3. Push handle back into position and rotate anticlockwise until the desired maximum showering temperature is reached. (It may be advisable to close the isolating valves at this stage to stop the flow).
3. Remove the strainer and place a bucket under the open strainer port. 4. Open the servicing valve and allow to flow until the water flows clear of debris. 5. Refit the strainer and cover. 6. Repeat for the other supply.
SETTING THE LIMIT STOP The limit stop can be set by the installer to prevent the control handle being turned to the full hot position.
Remove the handle by prising out the Trevi index and removing the screw. The handle will then pull off.
4. Pull handle off taking care not to rotate the cartridge. 5. Align the limit stop so that the stops just touch and push down (see Figure 12). 6. Use handle to turn the fitting off. 7.
Remove the handle and refit in the correct alignment.
8. Refit the screw and replace the index.
Maintenance The pressure balancing mechanism seldom fails and the possibility of blocked strainers should be investigated before contemplating replacement. Should the valve have been inadvertently installed without the in-line strainers, however, it is possible that the check valves, located at the back of the PBV mechanism, may have become restricted or blocked by water borne debris. Should it become necessary to replace or service any of the components in the pressure balancing mechanism precede as follows: 1.
Remove the Trevi index cap from the centre of the control handle (53) and pull off the handle.
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INSTALLATION GUIDE 2. Remove the screws retaining the exposed body cover and slide off the cover (5). 3. Undo the three screws (43) retaining the sequential cartridge (43b). 4. The cartridge (43b) can then be removed 5. At this stage the pressure balancing mechanism (46) can be removed by undoing the three screws (44) holding the mechanism retaining plate (47). 6. The plate can then be lifted off and the mechanism pulled out. 7.
The check valves on the inlet (back) of the PBV mechanism can now be pulled out and cleaned if necessary (Figure 13)
8. Assemble in reverse order.
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A5109 SEQUENTIAL PBV BUILT-IN
Figure 14 Sequential PBV Built-in A5109
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A5133 SEQUENTIAL PBV EXPOSED
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Figure 15 Sequential PBV Exposed A5133
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A5109 BUILT-IN & A5133 EXPOSED SEQUENTIAL PBV SPARE PARTS LIST
13 Part No’s
Desctiption
Part No’s
Desctiption
1
Cover plate trim
30
Plaster guard
2
Cover plate
31
Adjustable connecting elbow
2a
Screw
32
Screw
3
Cover plate grommet
33
1/2in compression nut
4
Elbow cover pipe slip
35
O ring
5
Exposed cover body
36
15mm compression olive
6
RH elbow cover (viewed pipe rising)
38
O ring
39
Outlet nipple
7
LH elbow cover (viewed pipe rising)
41
Inline filter & service valve
8
Back inlet elbow cover
43
Cartridge fixing screw
9
Cover plate wall seal
43b
Sequential cartridge
14
Screw
44
Screw
25
Wall plug
45
PBV B/I body
26
Valve body stabilising bed polystyrene
46
PBV mechanism
47
PBV mechanism retaining plate
53
PBV sequential handle
27
Wall fixing screw
29
Valve shroud
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CUSTOMER CARE HELPLINE
01482 499380 FAX LINE 01482 499611 Trevi Showers. The Bathroom Works, National Avenue, Kingston upon Hull, HU5 4HS England. Telephone: 01482 470788 Fax: 01482 445886
Trevi Showers pursue a policy of continuing improvement in design and performance of its products. The right is, therefore, reserved to vary specifications without notice.
Trevi Showers is a division of American Standard Plumbing (UK) Ltd.
T086 6/01
