Fixed-orifice, non-pressure compensated, flow control valve with reverse flow check
This valve is a fixed-orifice, non-pressure-compensated flow control with a reverse flow check. The flow setting is specified by the user and is set at the factory.
- Customer must specify the orifice diameter.
- All 2-port flow control cartridges are physically and functionally interchangeable (i.e. same flow path, same cavity for a given frame size). However, cartridge extension dimensions from the mounting surface may vary.
- These are essentially check valves with bypass orifices. The flow path matches Sun's flow controls and can be used in any flow control manifolds. Valves with the opposite direction of flow can be found under check valves with bypass orifices.
- Because these valves are non-compensating devices, the fixed orifice size will regulate flow through the valve in proportion to the square root of the pressure differential across ports 1 and 2.
- The customer specified orifice diameter is stamped on one of the cartridge's hex faces.
- 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-18A |
Series | 4 |
Capacity | 120 gpm480 L/min. |
Maximum Operating Pressure | 5000 psi350 bar |
Orifice Range | .016 - .218 in.0,4 - 5,5 mm |
Valve Hex Size | 1 5/8 in.41,3 mm |
Valve Installation Torque | 350 - 375 lbf ft474 - 508 Nm |
Seal kit - Cartridge | Buna: 990018007 |
Seal kit - Cartridge | Polyurethane: 990018002 |
Seal kit - Cartridge | Viton: 990018006 |
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.
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.
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