Pressure shut-off valve, Pilot operated Types DA …

1 DA, DAW1/12RD 26 411 2003by Bosch Rexroth AG, Industrial Hydraulics, D-97813 Lohr am MainAll rights reserved. No part of this document may be reproduced or stored, processed, duplicated or circulated usingelectronic systems, in any form or by means, without the prior written authorisation of Bosch Rexroth AG. In the eventof contravention of the above provisions, the contravening party is obliged to pay 26 411 : 26 412 Pressure shut-off valve, Pilot operatedTypes DA and DAWN ominal sizes 10, 25, 32 Series 5 XMaximum operating Pressure 315 barMaximum flow 240 L/minTyp DA 30 -2-5X/100-17H5915/98 ContentsDescriptionPageFeatures1 Ordering details2 Function, section3 Symbols4 Technical data4 Characteristic curves5 Unit dimensions6 to 8 Subplates9 and 10 Circuit examples11 Features For subplate mounting:For subplates (must be ordered separately), see pages 9 and 10 For installation in manifolds 4 adjustment elements.

2 Rotary knob Sleeve with internal hexagon and protective cap Lockable rotary knob with scale Rotary knob with scale 4 Pressure ratings Solenoid actuated unloading via a built-on directional valveRE 26 411 , DAWDA 5X *ABPTABPTW ithout directional valve = No codeWith built-ondirectional valve= WPilot operated valve= No codePilot valve withoutmain spool assembly= C(Do not state nominal size) Pilot valve withmain spool assembly= C(state nominal size 30)Nominal size 10= 10 Nominal size 25= 20 Nominal size 32= 30De-energised closed= A 1)De-energised open= B 1)Adjustment elementsRotary knob= 1 Sleeve with internal hexagon and protective cap= 2 Lockable rotary knob with scale= 3 2)Rotary knob with scale= 7 Series 50 to 59= 5X(50 to 59: unchanged installation and connection dimensions)Settable Pressure range0 to 50 bar= 5050 to 100 bar= 100100 to 200 bar= 200200 to 315 bar= 315 Further detailsin clear textNo code =NBR sealsV =FPM seals(other sealson request) Attention!

3 The compatibility of the sealsand Pressure fluid has to betaken into account!Electrical connection typeK4 3) =Individual connection; withcomponent plug to DIN 43 650-AM 2 ,without plug-in connectorNo code =Without hand overrideN 1) =With hand overrideN9 1) = With protected hand overrideG24 1) =24 V DCW230 1) = 230 V 50/60 Hz ACNo code =Without directional valve6E 4) = With directional valve (high performance valve)No code =Internal Pilot oil drainY =External Pilot oil drainSwitching Pressure differential (P A)10 =In the mid range 10 %17 =In the mid range 17 %(also see characteristic curves on page 5)1)Ordering details only required for the version with built-ondirectional valve DAW 2)H-key to material no.

4 00008158 is included within thescope of supply3)Plug-in connector must be ordered separately (see below).4)Catalogue sheet RE 23 178 Ordering detailsPreferred Types and standard components arehighlighted in the RPS (Rexroth Price list Standard).agreyR900074683 ablack R900057292R900313933R900310995 With dindicator light andZ diode protective circuitry24 VWith rectifier12 .. 240 VWith indicator light12 .. 240 VOrdering details: plug-in connectors to DIN 43 650 A and ISO 4400 for component plug "K4"ValvesideColourMaterial furtherplug-in connectorssee RE 08 006 Without circuitryDA, DAW3/12RE 26 411 (P)TAP621311 function of this valve is basically the same asthe DA valve.

5 A solenoid actuated directionalvalve (15) can, however switch the set cut-offpressure which is under the Pilot valve (2) eitherfrom P to T or from P to control valves type DA/DAW are Pilot operated pressureshut-off are used to switch a pump flow over to unpressurised by-passas soon as the accumulator loading Pressure is reached. Furtherapplications for the valve are in systems that have high and lowpressure pumps. In this case the low Pressure pump is switched tounpressurised by-pass as soon as the set high Pressure is shut-off valves basically consist of the main valve (1) withthe main spool assembly (3), Pilot valve (2) with Pressure adjustmentelement and check valve (4).

6 In size 10 valves , the check valve ( )is built into the main valve (1). In valve sizes 25 and 32 the checkvalve ( ) is built into a separate plate installed under the mainvalve (1). Pressure shut-off valve type DA Diverting pump flowfrom P to A to P to pump delivers flow via check valve (4) into the hydraulic system(P to A). Pressure in port A acts via Pilot line (5) on the Pilot controlspool (6). At the same time, Pressure in port P passes via orifices (7)and (8) to the spring loaded side of the main spool (3) and ball (9) inthe Pilot valve (2). As soon as the set cut-off Pressure in the hydraulicsystem is reached, the ball (9) lifts off against spring (10).

7 Pressurefluid now flows via orifices (7) and (8) into spring chamber (11).From here, the fluid is returned to tank either internally via controlline (12) in valve type or externally via control line (13) invalve type Due to orifices (7) and (8), a Pressure drop isnow present at the main spool (3). The main spool (3) now lifts off itsseat and opens the connection from P to T. The check valve (4) nowcloses the connection from A to P. The ball (9) is now held open bythe system Pressure via Pilot spool (6). Diverting pump flowfrom P to T to P to area of the Pilot spool (6) is 10 % or optionally 17 % greaterthan the effective area of the ball (9).

8 The effective force on the pilotspool (6) is, therefore, 10 or 17 % greater than the effective force onthe ball (9).When the actuator Pressure falls in relation to the cut-off pressureby a value which corresponds to the switching pressue differential,(see characteristic curve on page 5) spring (10) pushes ball (9) on toits seat. Pressure is then built up on the spring loaded side of themain spool (3). In conjunction with spring (14), this closes the mainspool (3) and isolates the connection from P to T. The pump flowpasses once more via the check valve (4) into the hydraulic system (Pto A). Pressure sut-off valve type DAWF unction, sectionType DA 10 1 5X/.

9 Type DAW 20 1 5X/.. 26 411 , DAWPATPATYPATBAPTBAPTPATBAPYTBAPTType 5X/.. 5X/..De-energisedclosedDe-energisedclose dType openDe-energised openType data (for applications outside these parameters, please consult us!)GeneralNominal sizeSize 10 Size 25 Size technical dataNominal pressurebar315 Maximum operating Pressure at port Abar315 (after switching from P to T) Pressure fluidMineral oil (HL, HLP) to DIN 51 524 1);Fast bio-degradable Pressure fluids toVDMA 24 568 (also see RE 90 221); HETG (rape seed oil) 1);HEPG (polyglycole) 2); HEES (synthetic ester) 2);other Pressure fluids on requestPressure fluid temperature range C 30 to + 80 for NBR seals C 20 to + 80 for FPM sealsViscosity rangemm2/s10 to 800 Maximum flow10 % versionL/min408012017 % versionL/min60120240 Degree of contaminationMaximum permissible degree of contamination of the pressurefluid is to NAS 1638 class 9.

10 We, therefore, recommend a filterwith a minimum retention rate of 10 set pressurebar50; 100; 200; 3151) suitable for NBR and FPM seals2) only suitable for FPM sealsDA, DAW5/12RE 26 411 curves (measured at = 41 mm2/s and = 50 C)By-pass Pressure in relation to the pump flow qV P (P T)Flow in L/min Flow in L/min Size 10 Size 25By-pass Pressure in bar By-pass Pressure in bar 1qV P max for 10% version2qV P max for 17% versionThese characteristic curves are valid for an outletpressure (T) = zero over the entire flow 32By-pass Pressure in bar Flow in L/min Switching Pressure differential in relation to the cut-off Pressure (P A)