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

Capacity: 60 gpm240 L/min. | Cavity: T-17A
RSHS8 : Pilot operated, balanced poppet sequence main stage with integral T-8A control cavity
Technical Features [ + ]

This valve is a normally closed poppet element that incorporates an integral pilot control cavity. It is externally drained, and 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 port 2, throttling flow to regulate the pressure. The pilot cartridge's setting determines the difference in pressure between the inlet (port 1) and the drain (port 3). These valves are insensitive to back pressure at port 2, up to the valve setting. They may be used to regulate pressure in place of 2-port relief valves if there is pressure in the return line.

  • All 3 port sequence cartridges are physically and functionally interchangeable (i.e. same flow path, same cavity for a given frame size).
  • Pilot flow continues to increase as the pressure at port 1 (inlet), relative to the pressure at port 3 (drain), rises above the valve setting.
  • The main stage orifice is protected by a 150 micron stainless steel screen.
  • Pressure at port 3 is directly additive to the valve setting at a 1:1 ratio and should not exceed 5000 psi (350 bar).
  • 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 solenoid operation, air pilot operation, and hydraulic pilot operation. See Pilot Control Cartridges.
  • Because the modulating occurs inside the cartridge these valves are immune to most of the problems associated with cavitation, namely noise and manifold erosion.
  • Will accept maximum pressure at port 2; suitable for use in cross port relief circuits.
  • 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.
Technical Data [ + ]
Cavity T-17A
Series 3
Capacity 60 gpm240 L/min.
Maximum Operating Pressure 5000 psi350 bar
Control Pilot Flow 15 - 20 in³/min.0,25 - 0,33 L/min.
Response Time - Typical 2 ms2 ms
Pilot Control Cavity T-8AT-8A
Pilot Control Valve Installation Torque 20 - 25 lbf ft27 - 33 Nm
Pilot Control Valve Hex Size 7/8 in.22,2 mm
Main stage leakage at reseat 10 drops/min.0,7 cc/min.
Valve Hex Size 1 1/4 in.31,8 mm
Valve Installation Torque 150 - 160 lbf ft203 - 217 Nm
Model Weight 1.50 lb0,70 kg
Seal kit - Cartridge Buna: 990217007
Seal kit - Cartridge Polyurethane: 990217002
Seal kit - Cartridge Viton: 990217006
Performance Curves [ + ]
FAQs [ + ]

There are exactly 250 Sun drops in a cubic inch or 15 in a cc.

A sequence valve opens when the pressure at port 1 exceeds the setting of the valve. When pressures at port 1 and port 2 both exceed the setting of the valve the valve goes full open, or sequences. When this happens flow can go in either direction, just so long as port 1 stays above the setting.

Pressure setting tolerances are listed in our Performance Data page. A link to this page can also be found in the Additional Resources tab of the applicable product page.

Notes [ + ]
  • Compound cartridge (pilot and main stage) assembly information is provided for reference only. Cartridges must be ordered separately and assembled at point of use.
Additional Resources [ + ]