General Pump RA2 User manual

RA2
Industrial Unloader
REGULATING & RELIEF VALVES REGULATING & RELIEF VALVES
GENERAL PUMP A member of the Interpump Group
• Regulates the operating pressure of the
system by releasing excess volume through
the by-pass
• Protects the system from over pressurization
• Traps pressure after the valve while reducing
pressure at the pump
SPECIFICATIONS
FEATURES
DIMENSIONS
Ref 300929 Rev. B
03-19
Part Number RA2
Max Pressure 3,050 PSI
Max Flow 61.0 PSI
Max Temperature 185° F
Port Size Inlet 1” BSP-F
Outlet 3/4” BSP-F
Bypass 1-1/4” BSP-F
Weight 10.6 lbs
General Pump
is a member of
the Interpump Group

GENERAL PUMP A member of the Interpump Group
RA2
Industrial Unloader
PARTS LIST
No. Part No. Description Qty.
1 F36341302 Regulating Knob 1
2 F97674700 Pin, .5 x 24, Inox 1
3 F92256700 Nut, M16, 1.5 2
4 F99308400 Screw, Hex, M8 x 30 4
5 F36340941 Body, Upper 1
6 F36338964 Screw, Pressure Regulating 1
7 F94847000 Spring, .18 x 8.2 x 1.5 28
8 F36339066 Valve Rod 1
9 F36341182 Plug 1
10 F36341064 Spacer 1
11 F36339770 Bushing 1
12* F90520000 Anti-extrusion Ring, 35.9 x 40, 1.5 1
13* 701126 O-ring, 34.6 x 2.62 1
14 F36339870 Guide Ring 1
15* F90271400 Ring, 22 x 30 x 1.5 LP 1
16 F36339366 Piston Control 1
17 F36339482 Spacer 1
No. Part No. Description Qty.
18* F90261000 Ring, Spacer, Ø 15 x 23 x 6, LP 1
19 F36339970 Guide Ring 1
20* 90386500 O-ring, 29.82 x 2.62 1
21* F90517750 Anti-extrusion Ring, 30.9 x 35 x 1.5 1
22 F36340070 Bushing 1
23* 701014 O-ring, 12.42 x 1.78 1
24* F36339566 Ring 1
25* 90385200 O-ring, 22.22 x 2.62 1
26* F90514450 Anti-extrusion Ring, 22.5 x 27 x 1.5 1
27* F36400166 Seat 1
28 F36341741 Body, Lower 1
29* F90403500 O-ring, 15.47 x 3.53 1
30 F36340270 Shutter 1
31 F94750600 Spring, 21 x 19.5, INOX 1
32* F90387500 O-ring, 37.77 x 2.62 1
33 F36341370 Nipple 1
* F2332 Repair Kit
Ref 300929 Rev. B
05-20
Torque Specs
4 14.75 ft. lbs (20 Nm)
19 11.06 ft. lbs (15 Nm)
33 202.83 ft. lbs (275 Nm)

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.

GENERAL PUMP A member of the Interpump Group
RA2
Industrial Unloader
INSTRUCTIONS FOR USE (CONT.)
Ref 300929 Rev. B
05-20
4.5 In the systems for hot water production, the
temperature of the liquid that comes into contact with
the valve must always be lower than the value stated
in this instruction manual and/or indicated on the valve
itself. Avoid the formation of steam or overheated
water.
IMPORTANT: When the temperature of the liquid is
close to the maximum value, the outside temperature
of the valve body is only slightly lower. Therefore,
take care in case of contact with the hot surface.
4.6 After use and/or before performing any operation on the
system or on the valve, release the pressure by using the
adjustment knob/screw and opening the gun or the control
device for a few seconds. The jet created by the residual
pressure must be directed downward in order to avoid damage
or injury.
4.7 For safety reasons, it is advisable to equip the high
pressure feeding line of the system also with a relief or safety
valve duly adjusted.
4.8 To connect the valve to the system it is referable to use
flexible hoses fitted in a way that they do not for 900elbows,
throttlings or siphons which could include harmful air bubbles.
The inside diameters of the hoses and fittings must be equal to
the correspondent inside diameters of the inlet, by-pass and
outlet threads of the valve. Moreover, it is necessary to correctly
choose the type of hose depending on the rated pressure and
flow rate; the hoses must always be used within their operation
limits as stated by the manufacturer and indicated on the hoses
themselves.
4.9 Tighten the fittings as follows:
G1” inlet fitting - torque wrench setting 147.5 Ft.lbs.(200 Nm)
G3/4” outlet fitting - torque wrench setting 88.5 Ft.lbs.(120 Nm)
G1-1/4” bypass fitting - torque wrench setting 221.3 Ft.lbs.(300 Nm)
In order to ensure the seal, fit a metal washer with a rubber ring
between the fittings, or use a proper sealant on the thread.
4.10 Always connect the valve by-pass fitting to a hose, in
order to avoid the excessive noise caused by the water outflow
through the by-pass without hose.
4.11 Before operating the system, it is advisable to start it for a
preliminary test run in order to check that the system is properly
installed.
4.12 In order to optimize the pump/valve coupling, it is nec-
essary to keep the valve operation, as a function of the pump
pressure and flow rate, within a maximum power of 81.5 HP. As
shown in the chart, this means using pumps producing a flow
rate of approx. 39.6 GPM for maximum working pressures of
3045 PSI , and generating a pressure of approx. 1958 PSI for
maximum flow rates of 60.7 GPM.
WARNING: Do not use the valve in the systems covered by
Directive 97/23/CE (PED) - Cath
5. MAINTENANCE
5.1 Maintenance and repair must be carried out by qualified and
authorized staff only. Before any operation, make sure that the
valve and the system are shut down and made unusable.
5.2 A correct maintenance helps extend the working life and
grants a better performance of the valve.
453 From time to time, it is necessary to check that the valve is
clean outside, and that there is no sign of leakage and/or
malfunctioning. If necessary, replace the involved parts. In case
of doubts, contact GP’s Customer Service Department.
5.4 Replace the valve parts with original spare parts only.
IMPORTANT: After maintenance, make sure that the
valve is re-assembled correctly and that the initial
conditions are restored. Comply with the torque wrench
setting values and set the pressure again as described
above.
4.5 The valve is entirely made of non-toxic and safe materials;
however, in case of disposal, we suggest you do not dispose of
it in the environment but take it to an authorized disposal center
or contact the Customer Service Department.
The valve shall not be tampered with for any reason
and/or used for any purpose other than the use it
has been designed for. In case of tampering, the
manufacturer disclaims all responsibility as to the
valve functioning and safety.
6. WARRANTY CONDITIONS
6.1 The period and conditions of warranty are specified in the
purchase contract.
6.2 Warranty is voided in case the valve is used for improper
purposes, used at higher performances than the rated ones,
repaired with non-original spare parts or if it turns out to be
damaged due to the non-compliance with the operating
instructions or to unauthorized tampering.

GENERAL PUMP 1174 Northland Drive • Mendota Heights, MN 55120
Phone: [phone] • Fax: [phone] • e-mail: [email protected] • www.generalpump.com
Ref 300929 Rev. B
05-20
GENERAL PUMP A member of the Interpump Group
RA2
Industrial Unloader
INSTRUCTIONS FOR USE (CONT.)
The valve should be mounted on the pressure line in
any position (horizontal or vertical) which will allow easy
access to the pressure adjusting screw. For proper oper-
ation the by-pass line internal diameter should be at least
1.25” at the narrowest point, and should not be connected
directly to the pump inlet line (see below for correct instal-
lation).