Fixed-orifice, pressure compensated flow control valve
Fixed-orifice, pressure-compensated flow controls provide precise flow regulation for meter-in or meter-out applications where there may be wide pressure fluctuations. A variety of flow rates are available.
- Will accept 5000 psi (350 bar) at ports 1 and 2.
- 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.
- The sharp-edged orifice design minimizes flow variations due to viscosity changes.
- Flow Tolerances A Flow Rate +/- 2.0 in³/min. (+/- 32 cc/min.) B Flow Rate +/- 2.5 in³/min. (+/- 40 cc/min.) D and F Flow Rates +/- 3.0 in³/min. (+/- 48 cc/min.) H and J Flow Rates +/- 4.0 in³/min. (+/- 64 cc/min.) L Flow Rate +/- 4.5 in³/min. (+/- 72 cc/min.)
- 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.
Cavity | T-8A |
Series | P |
Capacity | .5 gpm2 L/min. |
Maximum Operating Pressure | 5000 psi350 bar |
Valve Hex Size | 7/8 in.22,2 mm |
Valve Installation Torque | 20 - 25 lbf ft27 - 33 Nm |
Seal kit - Cartridge | Buna: 990008007 |
Seal kit - Cartridge | EPDM: 990008014 |
Seal kit - Cartridge | Polyurethane: 990008002 |
Seal kit - Cartridge | Viton: 990008006 |
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.
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.
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