14
Valve Orientation and Installation
The pressure reducing valve can be installed in any orientation but should not be under water or dirt due to the risk of
frost damage and dirt accumulating inside the diagram cap. The valve should be located so that the entire pipe system is
operating under a controlled pressure with the possible exception of hose taps. A ball valve is provided in the set as the
primary system isolation point and is commonly threaded into the PRV.
Commissioning
The device is factory pre-set at 300kPa but is adjustable via the adjusting screw located at
the top of the diagram cover. Turn it clockwise to increase the pressure and anticlockwise
to decrease it. We recommend a pressure differential > 20% between the resting pressure
and the cold water expansion valve (600kPa) and the pressure limiting valve to minimise
water loss due to expansion which can also prevent premature seat failure. Therefore DO
NOT do not adjust the PRV higher than 480kPa.
Maintenance
Impurities in the water supply can accumulate and deposit on the valve’s filter gauze
and seal seats causing a reduction in flow and or downstream pressure. Periodically
clean the filter and check or replace the internal cartridge removing the upper cap and
extracting the complete assembly while the valve body remains in line. Replacement
cartridge assemblies are available as a spare part.
4. Caleffi Cold Water Expansion Valve
DSV312460 15mm (120 and 180L models)
DSV311560 20mm (250, 300, 350 and 400L models)
The cold water expansion valve is a non-adjustable 600 kPa safety valve which allows
the escape of cold water due to the increase in pressure that accumulates inside the
cylinder during a heat cycle.
Technical Specification
Body:
Brass EN 12165 CW617N
Cover:
Brass EN 12165 CW617N
Seat:
Stainless steel
Control stem:
Brass EN 12164 CW614N
Obturator seal:
EPDM
Membrane:
EPDM
Spring:
Steel EN 12270-1
Control knob:
ABS
Nominal pressure:
PN 10
Working temperature range:
5 - 110°C
312460 Threaded connections:
15mm x 15mm
311560 Threaded connections:
20 x 20mm
Set pressure:
600kPa
Max. opening overpressure:
Pset +20%
Min. closing differential:
Pset -20%
Valve Orientation and Installation
The cold water expansion valve must be fitted to the lower port (see dimensional drawings) to ensure it draws only cold
water while in operation. The cold water expansion valve must be installed according to the flow direction indicated
by the arrow on the valve body and can vent horizontally or facing down but never facing up. This prevents deposits of
impurities from affecting correct functioning. The CWE port is vertically aligned with the TPR port for easy connection to a
shared waste pipe.
