Relief assembly with reverse flow check


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

This assembly consists of a 30 PSI check and a pilot-operated, balanced-piston relief cartridge which is a normally closed pressure regulating valve. When the pressure at the inlet (P port) reaches the valve setting, the valve starts to open to tank (T port), throttling flow to regulate the pressure. These valves are accurate, have low pressure rise vs. flow, they are smooth and quiet, and are moderately fast.

This assembly also incorporates an air-bleed and start-up cartridge which is used to purge air trapped in the system to help reduce power requirements and facilitate pump priming during the start-up of blocked center circuits.

Technical Data [ + ]
Body Type Line mountLine mount
Capacity 25 gpm95 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 [ + ]