HY-TS38-20 (Proportional Relief Valve)

A screw-in, cartridge-style, direct acting, single stage, poppet-type hydraulic relief valve, which can be infinitely adjusted across a prescribed range using a variable electric. Pressure output is proportional to DC current input. This valve is intended for use as a pressure limiting device in demanding applications.


The TS38-20 blocks flow from ① to ② until sufficient pressure is present at ① to offset the electrically induced solenoid force. With no current applied to the solenoid, the valve will free flow from ① to ②.

Note: back pressure on ② becomes additive to the pressure setting at a 1:1 ratio.


Technical specification (for application beyond these parameters, please contact with us)



Installation position

When possible, the valve should be mounted below the reservoir oil level. This will maintain oil in the armature preventing trapped air instability. If this is not feasible, mount the valve horizontally for best results.

Storage temperature (℃)

-20℃ to +55℃

Ambient temperature (℃)

-20℃ to +50℃


Hydraulic specification

Max. operating pressure

241 Bar (3500psi)

Rated flow

A: 11.4 lpm (3 gpm) at 20 bar (290 psi) pressure drop;

B: 11.4 lpm (3 gpm) at 10 bar (150 psi) pressure drop;

C: 11.4 lpm (3 gpm) at 5.5 bar (80 psi) pressure drop

Flow path

Free flow: ① to ② coil de-energized;

Relieving: ① to ② coil energized


(with dither of 250 Hz)

3.3% (without dither: 7% maximum)

Dither frequency

150 Hz or higher

Step reponse

T on <50 ms; T off <7 ms

Hydraulic fluid

Mineral oil, phosphate-ester


7.4 ~ 420 cSt (50 ~ 2000 sus)


-40℃~+120℃ (-40~250°F), with NBR seals


HY08-2, see page H.1.2

Max. pilot flow

0.76 Lpm (0.2 gpm)


Electrical specification

Max. Control current

12 VDC coils: 1.10A;

24 VDC coils: 0.55A

Relief pressure range

(from zero to max. control current)

A: 0-207 bar (0-3000 psi);

B: 0-138 bar (0-2000 psi);

C: 0-69 bar (0-1000 psi)

Control signal


(significant improvements in valve performance occur with superimposed dither, with either control method.)


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