GENERAL PUMP
A member of the Interpump Group
RA2
Industrial Unloader
INSTALLATION AND INSTRUCTIONS FOR USE
Ref 300929 Rev. B
05-20
1. GENERAL INFORMATION
1.1 The
RA2
automatic unloader is a manually adjustable,
pressure operated device, which, according to its setting, limits
the pumps/system pressure by conveying the excess of water to
the by-pass. Moreover, when the outlet flow is blocked, this
device totally releases the flow, and keeps under pressure the
portion of the system following the valve, while it reduces the
pressure in the portion of the system preceding the valve
1.2 Since the
RA2
valve is used in conjunction with a high
pressure water pump/system, which shall be called hereafter
only “system”, installation and use must be suited to the type of
system used and comply with the safety regulations in force in
the country where the valve is used.
1.3 Before using the valve, make sure that the system to valve
is used with is certified to comply with the relevant directives
and/or regulations.
1.4 Before installing and using the valve for the first time, we
suggest you check that it is undamaged and make sure that the
rated features correspond to the required ones. If this is not the
case, do not use the valve and contact the Customer Service
Department.
1.5 In order to install the valve correctly, follow the instructions
for the water inlet, outlet and by-pass connections, as stated in
this manual and/or the valve itself.
2- PACKAGE
2.1- Packages must be handled in compliance with the instruc-
tions stated on the packages themselves and/or provided by the
manufacturer.
2.2- In case the valve is not used immediately, it must be stored
in its package and placed in areas which are not exposed to
the weather and protected from excessive humidity and from
direct sunlight. Moreover, it is advisable to place wooden pallets
or other types of pallets between the package and the floor, in
order to prevent the direct contact with the ground.
2.3- The package components must be disposed of in compli-
ance with the relevant laws in force.
3. INSTRUCTIONS FOR PRESSURE SETTING
3.1 In order to obtain a correct adjustment and consequently a
proper functioning of the valve, always make sure that, when
working at the maximum pressure, the valve by-pass keeps
releasing a quantity of water equal to 5% of the total flow rate.
In case the flow rate at the by-pass is close to zero or exceeds
15% of the maximum flow rate, this could cause failure, early
wear and result in situations of danger.
The positions mentioned in the following instructions refer to
those shown in the parts list on page 2.
3.2 Connect the valve to the water system and follow these
steps:
3.2.1 Loosen the nut (pos. 3).
3.2.2 Unscrew the knob (pos. 1) in order to completely release
the springs.
2.2.3 Open the gun or the water control device and start the
system. Make sure the air contained in it is fully ejected.
3.2.4 Keeping the gun or the water control device open, start
adjusting the pressure by screwing down the knob (pos. 1).
Alternate the adjusting operations with a few openings and
closings of the gun or of the control device. When the desired
pressure has been reached, open and close the gun/control
device a few times again in order to stabilize the various
components (seals, springs, etc.). Check the pressure valve
again and correct if necessary.
3.2.5 Screw down the lower nut (pos. 3) up to contact with the
body. Lock the two nuts (pos. 3) by tightening the upper nut to the
lower nut.
3.2.6 In order to obtain working pressures lower than the
maximum set pressure, unscrew the knob (pos. 1).
In case of doubts, do not hesitate to contact the GP Service
Department.
IMPORTANT: During use, never exceed the maximum
values of pressure, flow-rate and temperature as stat-
ed in this document and/or indicated on the valve.
4. WARNINGS
4.1 The installation and the setting of the maximum pressure
must be made by qualified staff only, who must have the required
skills to handle high pressure systems and be informed of the
operating and safety instructions contained in this manual.
4.2 The installer must provide the ultimate consumer with the
proper instructions for the correct use of the system the valve is
used in connection with.
4.3 Use soft and filtered water only. In case of salt water and/or of
water containing solid particles of a size exceeding 360µm, the
internal components of the valve will be subject to quick wear;
furthermore, this might compromise the correct functioning of the
valve. Addition agents can be used in the water, provided that
they are biodegradable and always complying with the
regulations in force in the country where the valve is used.
4.4- Use guns and/or other control devices ensuring a
perfect seal when closed. Leakages may compromise the
correct functioning of the valve.