Da/Daw...L5X Type Pilot Operated Unloading Valve Hydraulic Valve

• Customization: Available
• Function: Pressure Regulating
• Installation: Plate
• Model NO.: DA/DAW...L5X
• Drive: Hydraulic
• Type: Pilot-Operated Type
• Pressure: Depending on Model
• Structure: Depending on Model
• Dimension(L*W*H): Depending on Model
• Maximum Pressure: 315 Bar
• Maximum Flow Rate: 240 L/Min
• Material: Rubber Cast Iron
• Color: Blue
• Temperature of Media: Room Temperature
• Power: Hydraulic
• Standard or Nonstandard: Standard
• After-Sales Service Provided: Online Support
• Transport Package: Strong Wooden Carton
• Specification: NG 10~32
• Trademark: Dingan
• Origin: China Hebei Xingtai Ningjin
• HS Code: 8481901000
• Production Capacity: 60000 Piece/Pieces Per Month
• Package Size: 10.00cm * 10.00cm * 10.00cm
• Package Gross Weight: 10.000kg

Product Description

Product Features
- For base plate installation
- Mounting surface complies with DIN24340 Type D and ISO 5781
- For oil block installation
-4 pressure ranges
-2 types of adjustment
    Knob
    Adjusting bolt with protective cover
- Solenoid unloading valve
    DA/DAW pressure control valves are pilot operated unloading valves. They are used to charge accumulators or to unload low pressure pumps in high/low pressure pump systems.
    The valve consists of a main valve (1) with a main valve core insert (3), a pilot valve (2) with a pressure regulating element and a non-return valve (4). In the case of a diameter 10 valve, the non-return valve (4.1) is located in the main valve (1). In the case of diameters 25 and 32, the non-return valve (4.2) is located in a separate base plate below the main valve.

DA type unloading valve

· Pump flow rate changes from P to A to P to T

The pump delivers oil to the hydraulic system (P→A) via the non-return valve (4). The pressure at port A enters the pilot control spool (6) via the control line (5). At the same time, the pressure at port P enters the spring-loaded side of the main valve spool (3) and the ball valve (9) in the pilot valve (2) via the orifices (7) and (8). Once the pressure at port A reaches the pressure set by the pilot valve, the ball valve moves away from its seat against the spring (10). The oil now flows into the spring chamber (11) via the orifices (7) and (8). The oil in the spring chamber is either discharged internally via the control line (12) (in the DA...L5X/... valve) or returned externally to the tank via the control line (13) (in the DA...L5X/Y... valve). Due to the orifices (7) and (8), there is a pressure drop between the upper and lower chambers of the main valve spool (3), causing the main valve spool to move away from its seat and open ports P to T. The non-return valve (4) now closes ports A to P. The ball valve (9) is now kept open by the pressure via the pilot spool (6).

· Pump flow rate changes from P to T to P to A

The area of the pilot valve plug (6) is 10% (or optionally 17%) larger than the effective area of the ball valve (9) on the valve seat. Therefore, the effective force acting on the pilot valve plug is 10% or 17% larger than the effective force acting on the ball valve.

When the actuator (system) pressure drops by a value equal to the conversion ratio, the spring (10) pushes the ball valve (9) against the valve seat. At this time, the pressure acting on the spring-loaded side of the valve core (3) cooperates with the spring (14) to close the main valve core (3) and isolate P to T. The flow of the pump is once again input into the hydraulic system (P to A) through the non-return valve (4).

DAW type unloading valve

The function of this valve is basically the same as that of the DA valve, except that a solenoid valve (15) is installed on the pilot valve, which can switch from P to A or P to T at the switching pressure set by the pilot valve.

 

Working medium temperature range		ºC	-30 ~+80 (NBR seals)
			-20 ~+80 (Fluorine Rubber Seal)
Nominal pressure		bar	315
Maximum flow rate		L/min	240
Working medium			Mineral oil; phosphate ester
Viscosity range		mm^2/s	10~800
Oil contamination degree			Maximum oil contamination according to NAS 1638 Class 9 and ISO 4406 Class 20/18/15
Weight		kg	Depending on Model

    Hebei Ding'an Hydraulic Machinery Co., Ltd. is a professional company integrating the research, production and sales of hydraulic valves. It is an ISO9001:2000 quality management system certified enterprise. The company currently has fixed assets of more than 10 million yuan, covers an area of 16,000 square meters, has strong technical force, and has more than ten years of experience in the development and production of hydraulic valves. It can quickly and high-quality develop various mining and engineering machinery hydraulic valves according to customer requirements.