SR1P2-A2

Proportional Directly Operated
Pressure Relief Valve

HA 5122
5/2012

3/4-16 UNF • pmax 350 bar (5076 PSI) • Qmax 1,5 L/min (0.396 GPM)

Screw-in cartridge design
Direct acting, poppet type
Three pressure ranges
Pressure output proportional to DC current input

Functional Description
The valve is designed for continuous regulation of
pressure in the circuit. The valve consists of the seat
(1), poppet (3), return spring (2), main spring (4), spring
support ring (5) and control proportional solenoid (6).
In the basic position (with the coil deenergized) the port
P is fully open to port T. Proportional increase of DC
current at solenoid (6) increase force to valve poppet
(3) through preload spring (4).
This blocks flow in direction P – T until sufficient pressure
is pre-sent to offset electrically induced solenoid force.
The minimum value of the cracking pressure can
be adjusted using the screw (7), position of which is
secured with the nut (8). The adjusting screw (7) can
also be used as the emergency control. Screw (9)

is used to air bleed the solenoid control system. To
ensure self-bleeding of the valve it is recommended to
install it in a vertical position with the solenoid facing
downwards. Bleeding process is necessary for the
proper functioning of the valve.
The valve can be used alone or as a built-in, pilot
operated pressure relief valve SR4P2-B2 (datasheet
No. HC 5117), or as a control valve of a built-in
indirectly controlled pilot operated pressure reducing
valve SP4P2-B3 (datasheet No. HA 5123).
The valve body and the adjustment screw are zinc
coated.

T
P

1