FPFK | Cartridges » Flow Control » Flow Control

This valve is a pilot-operated, normally closed, electro-proportional throttle with reverse free-flow check. Energizing the coil generates an opening force on the pilot stage which vents the main stage poppet to open proportionally. Metered flow is from port 1 to port 2 with reverse free flow from port 2 to port 1.

Capable of operating with pressures up to 5000 psi (350 bar).
Coils are interchangeable with Sun's other full flow, solenoid-operated valves and can be mounted on the tube in either direction.
This cartridge has several manual override choices, including no manual override. See Option Configuration.
For optimum performance, an amplifier with current sensing and adjustable dither should be used. Dither should be adjustable between 100 - 250 Hz.
The momentary/twist override option "E" allows the operator to shift the valve by twisting the manual override clockwise 90 degrees.
Cartridges configured with EPDM seals are for use in systems with phosphate ester fluids. Exposure to petroleum based fluids, greases and lubricants will damage the seals.
Capacities rated at 200 psi (14 bar) differential and maximum rated coil current.
Maximum Deadband (as a percentage of command) B Flow Rate = 28% D Flow Rate = 32%
Maximum Hysteresis at 200 psid (14 bar) B Flow Rate = 2.2 gpm (9 L/min.) D Flow Rate = 5.2 gpm (20 L/min.)
Minimum Capacity at 1000 psid (70 bar) B Flow Rate = 25 gpm (94 L/min.) D Flow Rate = 49 gpm (185 L/min.)
Depending on circuit requirements, a reverse free flow check bypassing the compensator may be needed when using the FPFK with an external compensator.
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.

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Note: Data may vary by configuration. See CONFIGURATION section.

Cavity	T-5A
Series	2
Capacity	20 gpm80 L/min.
Recommended dither frequency	100 Hz100 Hz
Maximum Valve Leakage at 110 SUS (24 cSt)	20 drops/min.@5000 psi20 drops/min.@5000 psi
Manual Override Force Requirement	5 lbs/1000 psi @ Port 133 N/100 bar @ Port 1
Deadband, nominal (as a percentage of input)	25%25%
Manual Override Stroke	.06 in.1,50 mm
Solenoid Tube Diameter	.75 in.19 mm
Valve Hex Size	1 1/8 in.28,6 mm
Valve Installation Torque	45 - 50 lbf ft61 - 68 Nm
Model Weight	.70 lb0,30 kg
Model Weight (with coil)	1.20 lb0,55 kg
Seal kit - Cartridge	Buna: 990203007
Seal kit - Cartridge	EPDM: 990203014
Seal kit - Cartridge	Viton: 990203006
Seal and nut kit - Coil	Viton: 990770006

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Performance Curve for FPFK: Pilot-operated, normally closed, electro-proportional throttle with reverse flow check

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How accurate are Sun's flow controls?

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 have a heat problem, will Sun's priority flow control help?

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.

What happens if I block the control flow (priority) port?

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

What happens if I block the bypass port on a priority flow control?

The valve acts as a 2 port restrictive flow control.

What is the compensating pressure of Sun's flow controls?

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.

How big is a drop of hydraulic oil?

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

What is the pressure drop through a flow control?

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.

What parts of the Sun cartridge valve are field serviceable?

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.

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991238 Momentary/twist operation, extended resolution, manual override control kit, E control
991243 Red momentary/twist operation, extended resolution, manual override control kit, E control

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