Pilot operated, balanced piston sequence assembly with reverse flow check


Function for YSEA
Port Designators [ + ]
Modifiers Ports
A, A/S Ports 1 & 2: 1/4" NPTF; Port 3: 1/4" NPTF;
B, B/S Ports 1 & 2: 3/8" NPTF; Port 3: 1/4" NPTF;
C, C/S Ports 1 & 2: 1/2" NPTF; Port 3: 1/4" NPTF;
D, D/S Ports 1 & 2: 3/4" NPTF; Port 3: 1/4" NPTF;
I, I/S Ports 1 & 2: SAE 6; Port 3: SAE 6;
J, J/S Ports 1 & 2: SAE 8; Port 3: SAE 6;
K, K/S Ports 1 & 2: SAE 10; Port 3: SAE 6;
U, U/S Ports 1 & 2: 3/8" BSPP; Port 3: 1/4" BSPP;
V, V/S Ports 1 & 2: 1/2" BSPP; Port 3: 1/4" BSPP;
W, W/S Ports 1 & 2: 3/4" BSPP; Port 3: 1/4" BSPP;
Technical Features [ + ]

Pilot-operated, balanced piston sequence valves will supply a secondary circuit with flow once the pressure at the inlet (port 1) has exceeded the valve setting. The pressure setting of a sequence valve controls the pressure at port 1 relative to the pressure at the drain (port 3). These valves are insensitive to back pressure at port 2 (sequence), 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. Additionally, these assemblies incorporate an integral check valve to provide reverse free flow from port 2 (sequence) to port 1 (inlet).

  • 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.
  • Pressure at port 3 is directly additive to the valve setting at a 1:1 ratio and should not exceed 5000 psi (350 bar).
  • Not suitable for use in load holding applications due to spool leakage.
  • 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 [ + ]
Body Type Line mountLine mount
Capacity 30 gpm120 L/min.
Mounting Hole Diameter .28 in.7,1 mm
Mounting Hole Depth ThroughThrough
Mounting Hole Quantity 22
FAQs [ + ]

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

Direct-acting valves are used to prevent over pressure, and pilot-operated valves are used to regulate pressure. If you are unsure, use a direct-acting valve. Sun's direct acting valves are very fast, dirt tolerant, stable, and robust. Sun's pilot-operated valves are moderately fast, they have a low pressure rise vs. flow curve, and they are easy to adjust.

Notes [ + ]
  • Important: Carefully consider the maximum system pressure. The pressure rating of the manifold is dependent on the manifold material, with the port type/size a secondary consideration. Manifolds constructed of aluminum are not rated for pressures higher than 3000 psi (210 bar), regardless of the port type/size specified.
Additional Resources [ + ]