Last update: 14/07/10
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DIMENSIONAL DRAWING
INSTRUCTIONS
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 unclean liquids. Choose
the valve in line with the data of nominal running (system rated pressure, max flow and max temperature). In any case, the pressure of
the machine should not exceed the permissible pressure rate imprimed on the valve.
INSTALLATION
This accessory, on a system that produces hot water, must be fitted in front of the heat generator. This product is bound to be
incorporated on a finished machine. On a system that generates hot water, anticipate the fitting of accessories that limit the accidental
increase of fluid temperature.
Always install a safety valve that protects the pressurized outlet channel.
Choose a correct nozzle size, which allows a regular discharge on bypass, at least 5% of the total flow of the system in order to
achieve a constant pressure value and avoid troublesome pressure spikes at closure. If the nozzle wears out, the pressure drops.
On installation of a new nozzle, re-adjust the system to the original pressure setting
OPERATIONS
The valve regulates the the max pressure of the system through a piston, which acts on a ball that, normally positioned, closes the
bypass opening. A check valve cuts out the delivery section, the pressure of which controls the drive of the piston.
Each regulation should be made when the system is operational and the nozzle open.
ATTENTION: The nut (pos.15) must never be removed mainly because, it is a mechanical safety feature that limits the
max pressure and avoids serious damage to persons and machine.
DISCHARGE SYSTEM AND WATER ADDUCTION
The bypass line should be returned into a tank with deflectors. With elevated pressure intake, it is necessary to install a pressure
reducer in order to have an even flow supply and to protect the circuit intake.
When the system is opened and closed frequently, it is recommended to install a thermal protector valve (VT3 or VT6) in order to
eliminate excessive temperature build.
