FLeX Series 3-way, direct-acting, electro-proportional, bypass/restrictive, priority flow control valve

Capacity: 30 gpm120 L/min. | Cavity: T-17A
FREP : FLeX Series 3-way, direct-acting, electro-proportional, bypass/restrictive, priority flow control valve
Technical Features [ + ]

This valve is a normally closed, electro-proportional, bypass/restrictive, priority flow control valve. The valve takes an input flow at port 1 and uses it to satisfy the priority flow at port 3. If the input flow exceeds the priority requirement, the excess is bypassed out port 2.
The valve pressure compensates the priority flow for precise flow regulation for applications where there may be wide pressure fluctuations. Port 2 may also be completely blocked so that the valve can be used as a 2-way, electro-proportional pressure compensated flow control from 1 to 3.

  • The valve's patent-pending design uses a pull-type solenoid that allows the main throttle spool to be less sensitive to flow forces, resulting in greater efficiencies, with more flow control using less power.
  • FLeX Series proportional valves are fully compatible with the XMD Expandable Mobile Drivers from Sun.
  • Designed and tested to 10 million on-off operational cycles.
  • Exceeds new NFPA test standard T2.6.1 R2014 for fatigue and burst pressure ratings.
  • Designed using CFD fluid simulation for optimized geometries.
  • All configurations of this valve include zinc-nickel plating as standard for 1000-hour salt fog protection.
  • This valve can be used with both the 740 Series high-power coils and 747 Series hazardous location coils.
  • A wide variety of coil termination and voltage options are available, with and without surge protection. See the CONFIGURATION section.
  • Coil connector options offer ratings up to IP69K. See individual coil product pages for details.
  • Both, priority and bypass flow, are usable up to the system operating pressure.
  • For optimum performance, an amplifier with current feedback and adjustable dither (80 - 250 Hz) should be used.
  • 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).
  • In applications where the priority flow will be blocked completely, bypass pressure drop will increase over time unless a leak path is provided for the priority flow.
  • Priority flow remains relatively constant regardless of variation in input flow.
  • The minimum bleed at port 3 must meet or exceed the published leakage numbers.
  • 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 30 gpm120 L/min.
Maximum Operating Pressure 5000 psi350 bar
Viscosity Range 35 - 2000 SUS2,8 - 380 cSt
Typical Valve Leakage at 110 SUS (24 cSt) from port 1 to port 3 at 1450 psi (100 bar) 30 mL/min.30 mL/min.
Typical Valve Leakage at 110 SUS (24 cSt) from port 1 to port 3 at 5000 psi (350 bar) 110 mL/min.110 mL/min.
Response Time - Typical 50 ms50 ms
Switching Frequency 3,600 max. cycles/hr3,600 max. cycles/hr
Valve Hex Size 1 1/4 in.31,8 mm
Valve Installation Torque 150 - 160 lbf ft203 - 217 Nm
Model Weight 1.20 lb0,55 kg
U.S. Patent # 10,969,03310,969,033
Seal kit - Cartridge Buna: 990017007
Seal kit - Cartridge Viton: 990017006
Proportional Performance Data [ + ]
Note: Data may vary by configuration. See CONFIGURATION section.
Hysteresis (with dither) A-spool: 9%, B-spool: 7%, C-spool: 5%A-spool: 9%, B-spool: 7%, C-spool: 5%
Linearity (with dither) A-spool: 2%, B-spool: 3%, C-spool 5%A-spool: 2%, B-spool: 3%, C-spool 5%
Repeatability (with dither) 1.5%1.5%
Recommended dither frequency 100 Hz100 Hz
Deadband, nominal (as a percentage of input) 25%25%
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.

No. This cartridge only controls flow in the 2 to 1 flow direction. From 1 to 2, the valve is always fully open.

Yes. All FLeX phase 1 valves are available in the SmartConnect schematic tool, and are also available for submittal to QuickDesign.

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.
Yes. All FLeX valves utilize the Sun floating nose design.
Nominal flow capacity is based on performance limits. Maximum flow capacity is based on pressure drop. When selecting any direct-acting solenoid valve, first check the performance limits plot, then check if pressure drop is acceptable.
Yes. The 747 series explosion proof coils can be used on any FLeX proportional valve.
Notes [ + ]
  • Please verify cartridge clearance requirements when choosing a Sun manifold. Different valve controls and coils require different clearances.
  • An additional 2.00 inches (50,8 mm) beyond the valve extension is needed for coil installation and removal.
Additional Resources [ + ]
Technical Tips
Technical Information
Coil Information [ + ]

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