Fixed orifice, bypass/restrictive, priority flow control with relief assembly


Function for YFEG
Port Designators [ + ]
Modifiers Ports
C, C/S Ports EF & P: 1/2" NPTF; Ports CF & T: 1/2" NPTF; Gage Port: 1/4" NPTF;
D, D/S Ports EF & P: 3/4" NPTF; Ports CF & T: 1/2" NPTF; Gage Port: 1/4" NPTF;
K, K/S Ports EF & P: SAE 10; Ports CF & T: SAE 10; Gage Port: 1/4" NPTF;
L, L/S Ports EF & P: SAE 12; Ports CF & T: SAE 10; Gage Port: 1/4" NPTF;
Technical Features [ + ]

This assembly consists of a bypass/restrictive, fixed-orifice, priority flow control which takes an input flow at port P and uses it to satisfy the priority flow at port CF. If the input flow exceeds the priority flow requirement, the excess is bypassed out port EF. The bypass flow may be used in a secondary circuit. The relief valve protects the controlled flow from over-pressurization, relieving excess flow out of port T.

  • Relief model RPEC is adjustable within 100 to 3000 psi (7 - 210 bar) with a factory setting of 1000 psi (70 bar).
  • The sharp-edged orifice design minimizes flow variations due to viscosity changes.
  • Customer must specify a flow rating. Factory set flow ratings are within +/- 10% of the requested setting.
  • Both priority and bypass flow are usable up to the system operating pressure.
  • Bypass flow is not available until priority flow requirements are satisfied.
  • Pressure at the bypass port (port EF) may exceed pressure at the priority port (port CF).
  • Maximum pressure at the priority port should be limited to 3000 psi (210 bar).
Technical Data [ + ]
Capacity 30 gpm120 L/min.
Body Type Line mountLine mount
Mounting Hole Diameter .41 in.10,4 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.

Reasons to anodize:

  • To increase corrosion resistance. Sun uses 6061-T651 aluminum. It is one of the most corrosion resistant aluminum alloys there is. Whether or not anodizing improves the corrosion resistance of 6061 aluminum is debatable. We have yet to have a manifold returned because of corrosion.
  • Appearance (color). The 2 colors that would appeal to Sun would be blue or black. Unfortunately these are the colors that are hardest to do consistently.
  • To provide a hard wear surface. Sun does not make parts-in-body valves. The manifold is just plumbing. We don't need a wear surface.
  • Because everyone else does it. Bad reason. 

Reasons to not anodize:

  • Cost. It's another process.
  • Logistics. When you make tens of thousands of manifolds a month and you anodize hundreds, it's a problem. Consistency. See above.
  • Stamping. After a body is anodized you cannot do any more stamping without making a mess.
    Inspection. Have you ever tried to look for burrs in a black anodized body? It's the old blackboard factory at night scenario.
  • Torque. You will experience an increase in breakaway torque when removing items from an anodized manifold.
  • Fatigue life. This is the best reason to not anodize. Fatigue failure is a very complex phenomenon. What it takes to initiate a crack is difficult to predict. What it takes to propagate a crack is readily defined. Anodizing produces a very thin, very hard, and very brittle surface on aluminum. The first time you pressurize an anodized aluminum manifold you have initiated fatigue cracks. Whether or not the stress is enough to propagate the cracks is a matter of pressure and manifold geometry. Anodizing an aluminum manifold grossly reduces the fatigue life by anywhere from 20% to 50%.

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 [ + ]