Watts DN100, Installation Manual

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3
EN
DRVD
pressure reducing valve
General
The DRVD pressure reducing valve is intended for use on
cold water and drinking water systems. It automatically
keeps the downstream pressure at the setpoint value, as
long as the inlet pressure is higher.
The DRVD is not affected by upstream pressure variations.
It is particularly recommended for collective and industrial
installations of all types.
Fields of application
For the protection of cold water and drinking water systems.
This device reduces and stabilises the pressure at a setpoint
value, irrespective of variations in upstream pressure and in
the flow drawn into the pipes. The DRVD is ideal for use as
a main expansion valve or secondary circuit control valve.
Note: The applications also depend on legislation in the
country of use. Please contact your national authorities
for further information.
Technical specifications
Type of fluid: drinking water/untreated water
Operation: horizontal position
Connection: flanged in accordance with EN 1092-2
Pressure gauge connection: Female (1/4’’)
Permissible operating pressure:
• PFA 16 bar: adjustment range 1.5 to 6 bar or 2 to 8 bar
• PFA 25 bar: adjustment range 4 to 12 bar
Maximum operating temperature: 40°C
Standards - Approval
Factory testing and hydraulic testing in accordance with EN
12266
Compliance with KTW requirements (Germany) and WRC
requirements (UK)
Flange connection in accordance with EN 1092-2, ISO
7005-2
1. Operating principle
The DRVD is a direct-acting pressure reducing valve:
it is controlled by the downstream pressure, which is
exerted under the piston against the force of the spring.
The downstream pressure is exerted directly in the control
chamber, under the upper part of the valve through a
special orifice.
The downstream pressure is balanced at all times by the
action of the spring, which causes the valve to move when
the system flow rate or pressure varies.
2.1 Preliminary inspection
Before installing the device, check that the system and water
quality meet the requirements of the regulations in force, in
particular NF EN 806-2, NF P40-20, DTU 60.1, and French
decree No. 2001-1220.
Also check that it has not been damaged in transit or during
handling. Repair if necessary.
Make sure that the pipes on which the pressure reducing
valve is to be installed are free from welding residue or other
debris. Leave enough space around the pressure reducing
valve for the purposes of adjustment and maintenance.
2.2 Mandatory installation conditions
Mandatory horizontal piping, DRVD adjuster screw facing
up. The DRVD must be fitted between 2 shut-off valves,
one upstream and one downstream, and must be protected
by a filter on the upstream side and a drain cock on the
downstream side.
Adhere to the diagram below.
The direction in which the valve must be fitted is shown by an
arrow on the valve housing.
1: DRVD pressure reducing valve
2 : filter
3 : air release valve
4 : isolation gate
5 : dismantling joint
You are advised to ensure ease of access by fitting an
isolation device and a filter on the upstream side to prevent
damage to the valve.
A dismantling joint must be installed to facilitate all assembly
and maintenance operations.
ACS
2. Installation instructions
upstream pressure reading
clockwise to increase pressure
downstream pressure reading