Last update: 30/11/2020
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DIMENSIONAL DRAWING
SELECTION
This product is to be utilized with clean fresh water, even slightly additivated with normal detergents. For use involving
different or corrosive liquids, contact the PA Technical department. Appropriate filtration should be installed when using
impure liquids. Choose the valve in line with the working data of the machine where to be installed (permissible pressure,
maximum flow rate and rated temperature of the system). In any case, any over-pressure of the machine must not
exceed the permissible pressure marked on the valve.
OPERATION
The valve limits the maximum pressure of the system. In the event of over-pressure, this relief valve will open to allow
the liquid to by-pass. During normal system operation, a shutter driven by a spring will keep the bypass opening close.
The set valve pressure can be regulated by adjusting the spring load by means of the dedicated adjusting screw.
INSTALLATION
This product is intended to be incorporated on a finished machine.On a machine that produces hot water,this valve must
be fitted upstream the heat generator. In addition it is recommended to install devices that limit the fluid temperature
accidental increase.
DISCHARGE SYSTEM AND WATER ADDUCTION
It is advisable to direct the bypass discharge liquid to a baffled tank that will reduce possible turbolence and air bubbles
generated by the immission of the bypass flow, which could be harmful for the pump.
When large flow volumes, close tho the max flow rate, are used, it is not advisable to return the bypass liquid to the
pump as this may cause dangerous pressure spikes, dangerous for the pump.
PRESSURE ADJUSTMENT/SETTING
The valve is supplied without pressure setting. The setting is done with the system “on”and with pressure inside the
circuit. The valve setting pressure is achieved by operating on the adjusting screw (pos.7): by screwing it, the set
pressure will increase.Once the desired pressure is attained, block the screw by locking the counternut (pos.7)
TROUBLESHOOTING
PROBLEMS
PROBABLE CAUSES
SOLUTIONS
Leaking out the bypass port during
normal system operation.
- Seat or shutter is worn.
- Foreing material is jammed between seat
and shutter.
- Replace.
- Clean.
- System working pressure is above
the set pressure.
- Re-set the system
pressure.
