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MODEL

RPKS8

Pilot operated, balanced poppet relief main stage with integral T-8A control

cavity

SERIES 4 / CAPACITY: 760 L/min. / CAVITY: T-18A

NOTE: DATA MAY VARY BY CONFIGURATION. SEE CONFIGURATION SECTION.

This valve is a normally closed modulating element that incorporates an integral pilot control cavity. It is a balanced

poppet design. The pilot control cavity will accept any T-8A pressure control cartridge. When the pressure at the

inlet (port 1) reaches the pilot control cartridge's setting, the poppet element starts to open to tank (port 2), throttling

flow to regulate the pressure. The pilot cartridge's setting determines the difference in pressure between port 1 and

port 2.

TECHNICAL DATA

Cavity T-18A

Series 4

Capacity 760 L/min.

Factory Pressure Settings Established at 15 L/min.

Maximum Operating Pressure 350 bar

Control Pilot Flow 0,25 - 0,33 L/min.

Response Time - Typical 2 ms

Pilot Control Cavity T-8A

Pilot Control Valve Installation Torque 27 - 33 Nm

Pilot Control Valve Hex Size 22,2 mm

Main stage leakage at reseat 0,7 cc/min.

Valve Hex Size 41,3 mm

Valve Installation Torque 474 - 508 Nm

Seal kit - Cartridge Buna: 990318007

Seal kit - Cartridge Polyurethane: 990018002

Seal kit - Cartridge Viton: 990318006

Model Weight 0.93 kg.

snhy.com/

RPKS8

Compound cartridge (pilot and main stage) assembly information is provided for reference only. Cartridges must be ordered separately and assembled at

point of use.

NOTES

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(W)MINIMUM CONTROL PRESSURE

W 100 psi (7 bar)

B 50 psi (3,5 bar)

(N)SEAL MATERIAL

N Buna-N

V Viton

TECHNICAL FEATURES

Because the modulating occurs inside the cartridge, these valves are immune to most of the problems associated with cavitation, namely noise and manifold

erosion.

All 2-port relief cartridges (except pilot reliefs) are physically and functionally interchangeable (same flow path, same cavity for a given frame size).

Will accept maximum pressure at port 2; suitable for use in cross port relief circuits.

Valve is relatively insensitive to varying oil temperatures and oil borne contamination.

Main stage orifice is protected by a 150 micron stainless steel screen.

Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.

NOTE: With the -8 control option, the main stage valve should first be installed to the correct torque value. The T-8A pilot control valve should then be installed into

the main stage valve to its required torque value.

The -8 control option allows the pilot control valve to be incorporated directly into the end of the relief cartridge via the T-8A cavity. These pilot control cartridges are

sold separately and include electro-proportional, solenoid, air pilot, and hydraulic pilot operation. See Pilot Control Cartridges.

Incorporates the Sun floating style construction to minimize the possibility of internal parts binding due to excessive installation torque and/or cavity/cartridge

machining variations.

PERFORMANCE CURVES

RELATED MODELS

RPKS Pilot operated, balanced poppet relief valve

Model Code Example: RPKS8WNCONFIGURATION OPTIONS