Élément logique, normalement fermé par ressort, à clapet équilibré - pression réglable

Capacité: 30 gpm120 L/min. | Cavité: T-22A
DKFP : Élément logique, normalement fermé par ressort, à clapet équilibré - pression réglable
Caractéristiques techniques [ + ]

Les éléments logiques normalement fermés qui commutent quand on les pilote et dont la pression pilote est réglable sont des valves à clapet hydrauliquement équilibrées entre les chambres 1 et 2. Le ressort principal maintient la valve fermée jusqu’à ce que la pression pilote, qui est réglée sur l’étage pilote intégré et appliquée à l’orifice 3, soit atteinte. A cet instant la valve commute à la position ouverte.

  • La conception de cette valve à clapet équilibré permet de commuter avec 350b aux orifices 1 et 2. La valve s’ouvre lorsque la pression de pilotage à l’orifice 3 dépasse la valeur de réglage de la pression de commutation.
  • toute contre-pression à l’orifice du drain augmente d’autant la valeur de pression de pilotage nécessaire à la commutation de la valve.
  • La valve se referme si la pression de pilotage tombe à moins de 85% de la pression de tarage.
  • Les orifices 1 et 2 sont étanches par rapport aux orifices 3 et 4. L’orifice 3 est étanche par rapport à l’orifice 4.
  • Le débit de fuite entre les orifices 1 et 2 est très faible : moins de 10 gouttes /min (0,7 cm3/min) à 350 bar.
  • Tous les orifices acceptent 350 bar.
  • Cette valve intègre le concept Sun de la cartouche à visser "flottante" qui permet de minimiser les contraintes internes dues à un couple de serrage excessif de la cartouche et/ou à des écarts d’usinage des cavités ou des cartouches.
Caractéristiques [ + ]
Remarque: Les caractéristiques peuvent changer selon la configuration. Voir la section CONFIGURATION.
Cavité T-22A
Taille 2
Capacité 30 gpm120 L/min.
Pression maximale de fonctionnement 5000 psi350 bar
Pression de pilotage minimale pour commuter la valve 300 psi20 bar
Contrôle du Débit de Pilotage See Performance DataSee Performance Data
Fuite Maximale à 24 cSt (100 SUS) 10 drops/min.@5000 psi0,7 cc/min.@350 bar
Dimensions du six pans de la valve 1"1/8 in.28,6 mm
Couple de serrage de la valve 45-50 lbf ft61 - 68 Nm
Taille du 6 Pans Creux de la Vis de Réglage 5/32 in.4 mm
Dimension du contre-écrou sur plat 9/16" in.15 mm
Couple de serrage du contre écrou 80 - 90 lbf in.9 - 10 Nm
Seal kit - Cartridge Buna: 990022007
Seal kit - Cartridge Polyurethane: 990022002
Seal kit - Cartridge Viton: 990022006
Performance Curves [ + ]
FAQs [ + ]

Il y a exactement 15 gouttes Sun dans un centimètre cube.

Direct acting valves are used to prevent over pressure and pilot operated valves are used to regulate pressure. If you are unsure, use a direct acting valve. Sun's direct acting valves are very fast, dirt tolerant, stable, and robust. Sun's pilot operated valves are moderately fast, they have a low pressure rise vs. flow curve, and they are easy to adjust.

Because of the very high ratio, the COFO has limited capacity. The discharge path is across a .050 inch (1,3 mm) diameter orifice. If you have large accumulators combined with low precharge pressures, this may not discharge the energy quickly enough. Using the COFO XDN cartridge in conjunction with an LODA XDN will provide capacity for larger applications.

The LH*A family of valves has been optimized to be used in a package to provide a power source for hydraulic tools. We can quantify the performance of the valve in static conditions but we cannot tell you how it will do in your application.

For instance: You want to use the valve as a compensator for a load-sense power steering package. When you are steering the machine and raising an implement, the valve is in a bypass mode (throttling on the bypass side). When the implement actuator bottoms out, pressure jumps to maximum and now the valve needs to change to the restrictive mode. Since the LH*A is balanced against pressure on the bypass side the only thing moving the spool is its own spring. The time this takes is dependent on where the spool was to begin with and where it has to go.

During this transition the steering will see the pressure differential across it suddenly change from about 150 psi (10 bar) to a system pressure of say 3000 psi (200 bar) and suddenly back down to about 150 psi (10 bar). When this scenario was described to me it was termed the broken thumb syndrome.

Sun does not and cannot provide technical support for this type of application. The valve has been successfully used in similar applications. What is necessary to make it work is up to whoever is doing the application.

Only external seals are serviceable.  Sun offers replacement seal kits for all cartridge models. The applicable kit part number can be found in the product page's Technical Data table or by using our Cartridge Seal Kit search function located under Accessories. Please note: Converting the external seals from one material to another does not ensure fluid compatibility with that material due to the existence of internal seals within the cartridge.
Ressources Complémentaires [ + ]