Fixed-orifice, bypass/restrictive, priority, flow control valve

Capacity: 25 gpm95 L/min. | Cavity: T-17A
FREA : Fixed-orifice, bypass/restrictive, priority, flow control valve
Technical Features [ + ]

Bypass/restrictive, fixed-orifice, priority flow controls take an input flow at port 1 and use it to satisfy the priority flow at port 3. If the input flow exceeds the priority flow requirement, the excess is bypassed out port 2. The bypass flow may be used in a secondary circuit.

  • Customer must specify a flow rating. Factory set flow ratings are within +/- 10% of the requested setting.
  • Maximum pressure at port 3 should be limited to 3000 psi (210 bar).
  • A tuneable adjustment control option provides up to +/- 22% variation from the nominal factory pre-set flow. Adjustment is done with +/- 3 turns of the adjust screw. Screw in (CW) to increase flow.
  • Both priority and bypass flow are usable up to the system operating pressure.
  • Priority remains relatively constant regardless of variation in input flow.
  • Bypass flow is not available until priority flow requirements are satisfied.
  • Pressure at the bypass port (port 2) may exceed pressure at the priority port (port 3).
  • The sharp-edged orifice design minimizes flow variations due to viscosity changes.
  • 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 [ + ]
Note: Data may vary by configuration. See CONFIGURATION section.
Cavity T-17A
Series 3
Capacity 25 gpm95 L/min.
Maximum Operating Pressure 5000 psi350 bar
Maximum Input Flow 60 gpm240 L/min.
Valve Hex Size 1 1/4 in.31,8 mm
Valve Installation Torque 150 - 160 lbf ft203 - 217 Nm
Adjustment Screw Internal Hex Size 5/32 in.4 mm
Locknut Hex Size 9/16 in.15 mm
Locknut Torque 80 - 90 lbf in.9 - 10 Nm
Model Weight 1.25 lb0,60 kg
Seal kit - Cartridge Buna: 990017007
Seal kit - Cartridge Polyurethane: 990017002
Seal kit - Cartridge Viton: 990017006
Performance Curves [ + ]
FAQs [ + ]

We claim +/- 10%. We set to +/- 5% in production testing to allow for differences in customers' conditions. If you want accuracy, stay in the bottom 2/3rds of the range. Our 12 gpm (45 L/min.) flow controls are quite flat at 9 gpm (34 L/min.) and dead flat below 6 gpm (23 L/min.), until you get to the bottom of the range. Below about .25 gpm (1 L/min.), spool leakage and orifice conditions start to limit accuracy.

I am afraid not. Unless you are overflowing your current valve and correctly size ours, you are not likely to notice any improvement. Priority flow controls are not efficient devices. They are an easy way to get more than 1 source of oil from 1 pump but they can generate a lot of heat. Try to size your actuators so the pressures are similar on both the priority and the bypass circuits. If you can't do that, try to have the lower flow leg be the lower pressure. The pump pressure is determined by whichever leg is higher and if there is flow that is taking a pressure drop that is not doing work it is creating heat.

All flow is blocked, hence the term priority. The priority flow has to be satisfied.

The valve acts as a 2 port restrictive flow control.

The spring force in our flow controls equates to about 100 psi (7 bar). This is high enough to give the valves acceptable capacity and not too high for proper circuit operation. 100 psi (7 bar) is the spring force; at the upper end of the flow control's range, the drop through the valve will be as high as 250 psi (17 bar) before it starts modulating.

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

In a meter-in flow control circuit if the pump is set at 3000 psi and the load is 2000 psi the drop through the flow control is 1000 psi. In a meter-out circuit with the load at 2000 psi the drop through the flow control is 2000 psi.

Only external seals are serviceable.  Sun offers replacement seal kits for all cartridge models. The applicable kit part number can be found in the product page's Technical Data table or by using our Cartridge Seal Kit search function located under Accessories. Please note: Converting the external seals from one material to another does not ensure fluid compatibility with that material due to the existence of internal seals within the cartridge.
Additional Resources [ + ]