120:1 ratio, pilot-to-close check valve
This valve is a pilot-to-close check cartridge that has a 120:1 pilot ratio. The valve is designed specifically to discharge an accumulator when the pump is turned off. With no pressure at the pump port (port 3), the valve is open between the accumulator (port 1) and tank (port 2). 60 psi (4 bar) at port 3 will close the valve for accumulator pressures up to 5000 psi (350 bar). When pump pressure at port 3 is below 300 psi (20 bar) there is a leak path from port 3 to tank (port 2) to ensure accumulator discharge when the pump is turned off. When pump pressure is above 300 psi (20 bar) the leak path closes for efficiency.
- Features hardened steel seats for excellent wear characteristics and contamination tolerance.
- Note: The discharge of the accumulator is across an .05 inch (1,27 mm) diameter orifice. The discharge time for large accumulators with low pre-charge pressures may be too long. In this case there are 2-valve circuits that greatly increase the capacity. See the Tech Tips (FAQs).
- The valve is a poppet design that results in very low leakage of stored fluid from the accumulator.
- Leakage of the pump signal only occurs when the pump is unloaded to below 300 psi (20 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||1 gpm (.05 inch)4 L/min. (1,3 mm)|
|Maximum Operating Pressure||5000 psi350 bar|
|Maximum Valve Leakage at 110 SUS (24 cSt)||5 drops/min.0,3 cc/min.|
|Valve Hex Size||1 1/8 in.28,6 mm|
|Valve Installation Torque||45 - 50 lbf ft61 - 68 Nm|
|Model Weight||.50 lb0,25 kg|
|Seal kit - Cartridge||Buna: 990202007|
|Seal kit - Cartridge||Polyurethane: 990002002|
|Seal kit - Cartridge||Viton: 990202006|
Because of the very high ratio, the COFO has limited capacity. The discharge path is across a .050 inch (1,3 mm) diameter orifice. If you have large accumulators combined with low precharge pressures, this may not discharge the energy quickly enough. Using the COFO XDN cartridge in conjunction with an LODA XDN will provide capacity for larger applications.
There are exactly 250 Sun drops in a cubic inch or 15 in a cc.
Direct-acting valves are used to prevent over pressure, and pilot-operated valves are used to regulate pressure. If you are unsure, use a direct-acting valve. Sun's direct acting valves are very fast, dirt tolerant, stable, and robust. Sun's pilot-operated valves are moderately fast, they have a low pressure rise vs. flow curve, and they are easy to adjust.
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