−1− WK 460 860 WK 460 860 04.1999r. PILOT OPERATED PRESSURE RELIEF VALVE TYPE DB/DBW DESCRIPTION OF OPERATION Pressure relief valves type DB... serve to limit pressure in a hydraulic system or in its part. Version DBW... is also used to unload pressure in a system. Application example : - DB... for setting up maximum pressure in a system - DBW... for actuation a pump without pressure the system reaches the value set by the position of the adjustment 5 and the spring 3 in the pilot valve, the fluid flows via the jet and the pilot poppet into the tank. A pressure drop occurs at the jet, which also affects both main spool surfaces. The main spool is thus pushed up allowing the excess fluid to drain out of the system into the tank. In subplate version, o-rings 6, 7 are fitted to secure sealing. Pilot operated pressure relief valve ( DB...) consists of a pilot valve 2 and main valve 1. Pressure in the system affects the main spool end via port P and at the same time the spring loaded side of the main spool and the poppet of the pilot valve 11 via jets 8, 10. At standstill, the pressure is equal on both sides of the spool. The spring 12 holds the main spool in the starting position. Ports P and T are separated from each other. If pressure in Size 10, 20, 30 31,5 MPa up to 600 dm 3 /min.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
−1− WK 460 860
WK460 860
04.1999r.
PILOT OPERATED PRESSURE RELIEF VALVE TYPE DB/DBW
DESCRIPTION OF OPERATION
Pressure relief valves type DB... serve to limit pressure in ahydraulic system or in its part. Version DBW... is also usedto unload pressure in a system. Application example :- DB... for setting up maximum pressure in a system- DBW... for actuation a pump without pressure
the system reaches the value set by the position of theadjustment 5 and the spring 3 in the pilot valve, the fluidflows via the jet and the pilot poppet into the tank.A pressure drop occurs at the jet, which also affects bothmain spool surfaces. The main spool is thus pushed upallowing the excess fluid to drain out of the system into thetank.In subplate version, o-rings 6, 7 are fitted to secure sealing.
Pilot operated pressure relief valve ( DB...) consists of apilot valve 2 and main valve 1. Pressure in the system affectsthe main spool end via port P and at the same time thespring loaded side of the main spool and the poppet of thepilot valve 11 via jets 8, 10. At standstill, the pressure isequal on both sides of the spool. The spring 12 holds themain spool in the starting position.Ports P and T are separated from each other. If pressure in
Size 10, 20, 30 31,5 MPa up to 600 dm3/min.
− 2 −WK 460 860
Pressure relief valve is also available with directional valveunloading. In the starting position, directional control valveas a pilot valve closes the return line in front of the pilotpoppet . The valve operates as already described. In theswitched position, the directional valve connects the spring
side of the main spool with the tank. This side of the spool isthus unloaded and moving along opens the connectionfrom P to T. The valve is available in two versions : in de-energized position normally closed or normally open.
Hydraulic fluid Mineral oil or phosphate ester
Nominal fluid viscosity 37 mm2/s at the temperature of 328 K
Pressure relief valve as remote control valve type DBT
1 - o-ring 9.2 × 1.8 - 2 pieces
PERFORMANCE CURVES, measured at ν = 41 mm2/s and T = 323 K
Seat D1 D2 D3Weight DBC
[ kg ]
Size 10 10 40 10 1.4
Size 20 20 45 20 1.4
Size 30 30 45 30 1.4
Seat D1 D2 D3Weight DBC
[ kg ]
Size 10 10 40 10 1.4
Size 20 20 45 20 1.4
Size 30 30 45 30 1.4
Minimum set pressure in relation to flow rateOperating pressure in relation to flow rate
−7− WK 460 860
0 100
10
20
30
200 300 400Q (dm /min)
p (M
Pa)
0 150
10
20
30
300 450 600Q (dm /min)
p (M
Pa)
0 100
0,5
1,0
1,5
2,0
200 300 400Q (dm /min)
p (M
Pa)
0 150
1
2
3
4
300 450 600Q (dm /min)
p (M
Pa)
Ciœnienie robocze w zale¿noœci od przep³ywu Najni¿sze ciœnienie nastawiania w zale¿noœci od przep³ywu
NG 20 NG 20
NG 30NG 30
3 3
3 3
Detailed
Minimum set pressure in relation to flow rateOperating pressure in relation to flow rate
SCHEMES
− 8 −WK 460 860
Mounting dimensions for subplate
Subplate for valves must be ordered sepatately
1 - Recess in subplate face for sizes 20 and 302 - Recess in subplate face for size 103 - Reference point for the recess in subplate face size 104 - Reference poin for the recess in subplate face sizes 20 and 305 - Hole for lackating pin for size 106 - Hole for lackating pin for sizes 20 and 307 - Mounting face
S izeBolts mounting the valve to
subplate perPN-74/M-82302 ( DIN 912 )
To rq u( Nm )
1 0 4 x M12 x 50 - 10.9 1 2 0
2 0 4 x M16 x 50 - 10.9 3 1 0
3 0 4 x M18 x 50 - 10.9 4 3 0
Note : Mounting bolts have to be ordered separately
(
Simplified
−9− WK 460 860
1 - Munting face of the valve2 - Recess in subplate
Bolts mounting thevalve to subplate
Torque[ Nm ]
Subplattype
Weigh
4 x M8 x 40 - 10.9PN - 74/M - 82302
( DIN 912 )37 G51/01 1 kg
Note : Mounting bolts have to be ordered separately
B11 D1 D2 D3 D4 D5 H1
85G3/8G1/2
2834
12 M12 9.5 30
102G3/4G1
42 47 24 M16 14 40
120G11/4G11/2
58 65 30 M18 14 48
H2 L1 L2 L3 L4
10 - 43 43 32
10 120 85.5 66 90.5
10 146 114 93.5 117.5
L11 L12 L13 L14 T1 T2
35.5 - 9.9 3.51315
9
- 33.5 11 -1719
8
- 44.5 12.5 -2123
14
L5 L6 L7 L8 L9 L10
7 100 57.5 20 57.5 35.5
11 128 90.5 20 67 55.5
20.5 158 120.6 22 89 76
Subplate for mounting the valve DBC ( not included with the valve )
Nominalsize Type B1 B2 B3 B4
10G406/01G407/01 106.5 - 52.6 32
20G408/01G409/01 127 100 70 35
30G410/01G411/01 146 120 86 41.3
B5 B6 B7 B8 B9 B10
22 130 64 26.2 11.8 27
35 154 70 28.5 13.5 35
41.3 174 82.5 31.8 13.9 41.3
(
− 10 −WK 460 860
DB
HOW TO ORDEROrders coded in the way showed below should be forwarded to the manufacturer.
⁄⁄⁄⁄⁄
VersionWithout unloading - with no codeWith unloading - W
TypeComplete valve - with no codePilot valve with main spool - C( for sizes 10 and 30 only )Pilot valvewithout main spool - C( do not quote nominal size )Pilot valve of remote control - T( do not quote nominal size )
Nominal sizeSize 10 = 10Size 20 = 20Size 30 = 30
Directional control valve ( for DBW only )In de-energized position closed = AIn de-energized position open = B
Mounting methodFor subplate mounting = with no codeFor threaded connection = G