• E, E/S

  Ports P, T, EF: 1" NPTF; Port ACC: 3/4" NPTF; Port G: 1/4" NPTF; Ports D, AUX, RS: 3/8" NPTF;
• F, F/S

  Ports P, T, EF: 1 1/4" NPTF; Port ACC: 1" NPTF; Port G: 1/4" NPTF; Ports D, AUX, RS: 3/8" NPTF;
• M, M/S

  Ports P, T, EF: SAE 16; Port ACC: SAE 12; Port G: SAE 4; Ports D, AUX, RS: SAE 6;
• N, N/S

  Ports P, T, EF: SAE 20; Port ACC: SAE 16; Port G: SAE 4; Ports D, AUX, RS: SAE 6;
• X, X/S

  Ports P, T, EF: 1" BSPP; Port ACC: 3/4" BSPP; Port G: 1/4" BSPP; Ports D, AUX, RS: 3/8" BSPP;
• Y, Y/S

  Ports P, T, EF: 1 1/4" BSPP; Port ACC: 1" Code 62; Port G: 1/4" BSPP; Ports D, AUX, RS: 3/8" BSPP;

This valve assembly is meant to charge an accumulator using a fixed displacement pump. It incorporates a ventable priority flow control valve. When the pressure reaches the set point of the valve, the priority flow control is vented and all of the pump flow is available to the system. When the pressure drops to the value determined by the fixed percentage of the pilot valve, the priority flow is used to recharge the accumulator. Only the priority flow is directed to the accumulator leaving the rest of the pump flow available to the system. The assembly has three additional features; a simple circuit that softens the unloading of the pump, a system over-pressure relief, and provisions for remote sensing of the accumulator pressure.

• When applying this assembly, a separate drain line is required to prevent erratic operation caused by tank line pressure fluctuations.
• NOTE: Careful consideration should be given when selecting an adjustment range. System pressure drops and flows tend to affect the operation of unloading valves. Low operating pressures combined with low differentials result in a very narrow band between unload and reset, requiring precise system design. High flow rates typically mean high pressure drops, which subtract from the differential the valve has to work with.
• The pressure setting and the resultant reseat pressure are in reference to the port 1 area of the QPA* pilot valve. Pump pressure will be higher and accumulator pressure will be lower due to pressure drop caused by flow. Use of the remote sense for accumulator pressure will minimize the error on the accumulator side of the circuit. Use of the remote sense is highly recommended.
• The porting on this assembly is large in relation to its capacity. This is done to encourage the use of correspondingly large piping to minimize problems caused by flow induced pressure drop.
• The spool design of the pilot valve allows it to maintain a fixed differential ratio because the areas are created by diameters on the spool that will not wear or change with use.
• The accumulator pilot valve must be set below any reliefs in the pump side of the system or severe heating could occur.
• The relief in this package is meant to be an over-pressure device. It is set higher than the highest setting of the pilot valve and capped.

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