Page 1345 - Softbound_Edition_19_en
P. 1345

Check valve
 Check valves                                                                                         Check valves

 cHaracteriSticS  Oil viscosity  υ = 30 mm /s  Non-return valve
 2
 BDERV3  ∆p = f (Q)  BERVA3  BERVB3  hydraulic pilot
 Pressure drop charakteristic
       1 Pressure drop A --> Cyl. or B --> Cyl.  Sandwich construction  NG4-Mini ®
       2 Pressure drop Cyl. --> A or Cyl. --> B
    with check valve fully open   • Q max  = 20 l/min
 p [bar]    • p max   = 315 bar
 25  K0119
 1
 20
            DESCRIPTION                        FUNCTION                           APPLICATION
 B
 A  P T  15  A  P T  B  2  A  P T  B  Sandwich type non-return valve NG4-Mini with   In the free flow direction, the volume flow opens   Pilot operated non-return valves are used to
 10         hydraulic pilot with interface according to Wand-  the valve seat against a spring.  The spring   shut off pressurised hydraulic cylinders, e.g.
            fluh standard. The valves allow a free flow in one   helps the valve close in the opposite direction.   in lifting or clamping fixtures, without leaking.
 5          direction and shut off in the opposite direction.   If pressure builds up in the opposite oil port,   The hydraulic cylinder can olny be moved in the
 0          3 different standard versions are available. The   this displaces the pilot piston and opens the   shut off direction if a directional valve directs
 0  2  4  6  8  Q [l/min]  steel  sandwich  body  is  phosphatised.  Good   non-return valve of the closed port. The pilot   the  volume  flow  into  the  opposite  port  and
            performance data and attractive design are the   pressure required is dependet on the pressure   releases the valve. Reliability in operation is
            hall marks of this quality product.  held by the valve seat.          increased ba a directional valve which connects
 dimeNSioNS                                                                       both oil ports to the tank in the neutral position.
                                                                                  Sandwich type elements NG4-Mini mean that
                                                                                  the  system  is  highly  flexible  and  save  both
 ∅  4,2  20  10                                                                   space and weight.

                                               TYPE CODE
                                                                                                     B       4  #
 30
                                               Mounting interface acc. to Wandfluh standard

                                               Type list / Function
 6,5  94  6,5                                        in A and B   DERV
                                               in A  ERVA   in B  ERVB
 40  30
 Thickness = 1,2                               Nominal size 4-Mini
 Dicke = 1,2
 Epaisseur = 1,2                               Design-Index (Subject  to change)


            GENERAL SPECIFICATIONS                                HYDRAULIC SPECIFICATIONS
 P          Description       Non-return valve hydraulic pilot    Fluid               Mineral oil, other fluid on request
 21  11  T  A  B  To  30  Nominal size   NG4-Mini acc. to Wandfluh standard  Contamination efficiency   ISO 4406:1999, class 20/18/14
            Construction      Sandwich construction                                   (Required filtration grade ß 10…16≥75)
            Mounting          3 holes for hexagon socket screw M5                     (refer to data sheet 1.0-50)
                              or studs M5                         Viscosity range     12 mm /s…320 mm /s
                                                                                                    2
                                                                                           2
 10         Connections       Connection plates                   Fluid temperature   -20…+70 °C
                              Mulit-station flange subplate       Peak pressure       p max  = 315 bar
 20                           Longitudinal stacking system        Opening pressure    p    = 2 bar
                                                                                       ö
            Ambient temperature   -20…+50 °C                      Pilot ratio         i = 1:8
            Mounting position    any                              Max. volume flow    Q max  = 20 l/min
            Fastening torque   M  = 5,5 Nm (Quality 8.8)
                                D
            Weight            m = 0,85 kg
 partS liSt
   Position  Article   Description  SYMBOLS / TYPES
   10   239.2003   Plug G1/2"  BDERV4          BERVA4                             BERVB4
   20     49.2212   Bounded seal 21,5x28,7x2,5
   30   173.0650   Seal plate PDSA03
   40   160.2045   O-Ring ID 4,5x1,5





 Technical explanation see data sheet 1.0-100
             A             P T             B     A            P T             B    A             P T            B




                                                                                  10
                                                                 5
 Wandfluh AG   Tel.  +41 33 672 72 72   E-mail:  sales@wandfluh.com   Illustrations not obligatory   Data sheet no.   Wandfluh AG   Tel.  +41 33 672 72 72   E-mail:  sales@wandfluh.com  20,5  Illustrations not obligatory   Data sheet no.
 Postfach   Fax  +41 33 672 72 12   Internet:  www.wandfluh.com   Data subject to change   2.7-65E 2/2   Postfach   Fax  +41 33 672 72 12   Internet:  www.wandfluh.com   Data subject to change   2.7-70E 1/2
 CH-3714 Frutigen                   Edition 03 26  CH-3714 Frutigen                                      Edition 03 26
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                                                                              30





                                     6,5                94                 6,5





                                                30              40


                                                        P
                                                    A        B
                                              27  14  T       To             40






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