2-way cartridge valves with spool position monitoring LFA..E79 (control cover)

Description

• Size 25
• Component series 6X
• Maximum operating pressure 420 bar
• Maximum flow 25000 l/min
• Size 25
• Component series 6X

Features

• Functional product design
• Modular set-up:
  • Cartridge valve with various options
  • Control cover in various variants for realization of selected functions
  • Hydraulic monitoring of the spool position
• Power and flow-optimized design:
  • High flows
  • Low pressure drops
  • High switching velocities
  • Low leakage oil flows

• Robust design:
  • High reliability
  • Long life cycle
• Other features:
  • Small installation size, low weight
  • Easy to service

Product description

2-way cartridge valves are elements that have been designed for a compact block design. The power section with connections A and B is installed into the control block in a receiving hole standardized according to ISO 7368 and closed with a cover. In most cases, the cover is also the connection from the control side of the power section to the pilot control valves.

By control with respective pilot control valves, the power section can be applied for pressure, directional and throttle functions or a combination of these functions. Particularly efficient solutions are realized by adjustment of the size to various flows of the individual ways of an actuator. The application of power sections of elements for multiple functions is very cost-effective.

2-way cartridge valves generally consist of control cover (1) and installation kit (2). The control cover contains the control bores and optionally a stroke limitation function, a hydraulically controlled directional seat valve or a shuttle valve according to the required overall function. Additionally, electrically operated directional spool or seat valves can be installed at a control cover. The installation kit consists of a bushing (3), ring (4) (only up to NG32), valve poppet (5), optionally with damping nose (6) or without damping nose (7) as well as closing spring (8).

The function of 2-way cartridge valves is pressure-dependent. This way, three crucial pressurized areas A1, A2, A3 are realized for the function. The area at valve seat A1 is observed as 100 %. Depending on the version, the annulus area A2 realized by grading is 7 % or 50 % of area A1. The area ratio A1 : A2 is respectively either 14.3 : 1 or 2 : 1. The area A3 is identical to the sum of areas A1 + A2. Due to the different area ratios A1 : A2 and the resulting different annulus areas (A2), the area A3 is one time 107 % and another time 150 % of the area A1 at the seat, which is observed as 100 %.

In general, the following applies:

The areas A1 and A2 are effective in opening direction. The area A3 and the spring are effective in closing direction. The direction of action of the resulting force from the opening and closing forces determines the spool position of the 2-way cartridge valve.

The 2-way cartridge valves can be passed from A to B or from B to A. Pressurization of area A3 by pilot oil discharge from channel B or external pilot oil supply, channel A is blocked without leakage.

Type code

Version
„CA“

Technical data

general

hydraulic

(For applications outside these values, please consult us!)

Diagrams/characteristic curves

(simulated with HLP46, ϑoil = 40±5 °C)

Size 25 (B → A), without damping nose "E"

Nominal size 25 (A → B), without damping nose "E"

Notice:

The indicated characteristic curves have been determined without inserted springs.

Other orifices upon request.

Symbols/Circuit diagrams

LFA . E79…

Electrical connection

Components

Cartridge element (design as seat valve with damping noses)

Cartridge valves are hydraulically controlled seat or spool valves with two working ports A and B and one control port X or two control ports X and Z for the version with differential spool. Y is generally the leakage oil connection. The valves are available in sizes 16, 25, 32, 40, 50, 63, 80, 100, 125 and 160.

Criteria for determination of the size include the flow to be controlled as well as flow resistance values of cartridge valves and their area ratios.

Control cover

By means of control cover (2), the bore of the cartridge elements is closed. They also serve as connection element between cartridge valve and pilot control valve.

Pilot control valve

At control covers for set-up of a directional spool valve (3) or seat valve (4), the porting pattern is realized according to ISO 4401 and DIN 24340.

The cartridge element (1) and the control cover (2) form a functional unit. It is calibrated at the factory and must not be disassembled or combined with other third-party components.

The closed spool position is monitored by the attached position switch (5).

Dimensions

Information

Downloads

2-way cartridge valves with spool position monitoring, passively controlled Data Sheet | RE21015 | 2019-07-01 | English | PDF | 2.3MB Product Groups: Logic elements - directional function