Fixed-orifice, bypass/restrictive, priority, flow control valve
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 +/- 15% of the requested setting.
- A tuneable adjustment control option provides up to +/- 20% 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.
- Maximum pressure at port 3 should be limited to 3000 psi (210 bar).
- 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.
|Capacity||3 gpm11 L/min.|
|Maximum Operating Pressure||5000 psi350 bar|
|Maximum Input Flow||7.5 gpm30 L/min.|
|Valve Hex Size||3/4 in.19,1 mm|
|Valve Installation Torque||20 - 25 lbf ft27 - 33 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||.20 lb0,10 kg|
|Seal kit - Cartridge||Buna: 990163007|
|Seal kit - Cartridge||Polyurethane: 990163002|
|Seal kit - Cartridge||Viton: 990163006|
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 (not really) 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.
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