Huade Hydraulic pays more attention to the practicality of its products. Pressure relief valve DB3U are competitive with well-know products with good quality and lower price. Huade Hydraulic has introduced cutting-edge technology from Rexroth due to two long-term cooperation with Rexroth. As a leading brand in China's hydraulic industry, Huade® pressure relief valves win wide market recognition and user trust. All branches of the enterprise have passed ISO9001, ISO14001 and OH SAS18001. Huade® leading products have received the CCS (China Classification Society) certificate and widely used in the marine industry.
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Size |
8 |
10 |
15 |
20 |
25 |
30 |
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Flow(L/min) |
Threaded connection |
100 |
200 |
400 |
600 |
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Subplate mounting |
- |
200 |
- |
400 |
- |
600 |
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Operating pressure (MPa) |
ports A,B,X.up to31.5 |
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Back pressure (port Y) (MPa) |
up to 31.5 |
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Min. Setting pressure (MPa) |
see operating curves |
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Max. Setting pressure (MPa) |
up to10 or 31.5 |
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Pressure fluid |
Mineral oil (for NBR seal)or phosphate ester(for FPM seal) |
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Viscosity range (mm ²/s) |
10 to 800 |
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Temperature range(℃) |
-30 to +80 |
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Size of directional valve |
see directional valve 4WE5 |
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Features:
▶ Subplate mounting
▶ Threaded connection
▶ Installation in manifolds
▶ 3 adjustment elements:
. Rotary knob
. Screw with internal hexagon and protective cap
. Rotary knob with scale
▶ Solenoid operated control via mounted directional valve
Application:
Pressure relief valve DB3U are used for the limitation of the operating pressure.
Types DB3U pressure valves are pilot operated pressure relief valves. They may be switched over to different (2 or 3 pressure stage) by solenoids actuated.
The pressure relief valves consist mainly of the main valve. 4/3,4/1-Directional control valve (Type WE5...) and three pilot valves.
In the de-energized condition the pressure in port A is set by pilot valve(7).
The pressure present in port A acts on the main spool (1). At the same time pressure is applied via the control lines (12) and (4), which are fitted with orifices (2) and (3), on the spring loaded side of the main spool (1) and at the poppet(6) in the pilot control valve (7). If the pressure in port A exceeds the value set at the spring (8), the poppet
(6) opens against the spring (8).
The signal for this comes internally via the control lines (12) and (4) from port A. The pressure fluid on the spring loaded side of the main spool(1) now flows via the control line (3), poppet (6) into the spring chamber(9). In type DB3U...30/..., it flows internally via the control line (10) to tank, or in type DB3U..30/..Y.., externally via the port Y. Due to the orifices (2) and (3) a pressure drop occurs at the main spool(1), the connection from port A to port B is open. Now the pressure fluid flows from port A to port B while maintaining the valve set operating pressure.
When solenoid “a” is energized: The pressure in port A is set by pilot valve II.
When solenoid “b” is energized: The pressure in port A is set by pilot valve I.
The setting pressure of pilot valve(7) should be higher than the setting pressure of the pilot I and II.
Type DB2U
Type DB2U pressure valves consist mainly of a directional control valve (Type WE5...) and three pilot valves, the function of this valve is basically the same as the valve type DB3U.
structure of Pressure Relief Valve DB3U
Symbols
Address
No. 27, Yangsha Road, Huilong Town, Nantong City, Jiangsu Province, China
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