2-way cartridge valves, directional functions LFA..D (high-pressure)

Description

Features

• Control cover for directional function

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 simultaneously 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 pressuredependent. This way, three crucial pressurized areas A1, A2, A3 are realized for the function. The area at the valve seat A1 is considered 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. In case of pressurization of area A3 by pilot oil discharge from channel B or external pilot oil supply, channel A is blocked in a leakage-free manner.

Type code

Orifice symbol		Symbol in ordering code
A**		A**		This orifice is designed as screw-type orifice. If an orifice is to be installed, the respective code letter with the orifice Ø in 1/10 mm has to be entered in the type designation. Example: A12 = Orifice with Ø1.2 mm in channel A.
Ø1,2				This orifice is designed as bore. No specifications are made in the type designation. (Orifice Ø in mm)
Z12				This orifice is designed as screw-type orifice. This is a standard orifice. No specifications are made in the type designation. (Orifice Ø in 1/10 mm)

Notices:

• For ordering code of orifices, see "Accessories"

• Additional functions with special numbers see "Information".

Technical data

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

Diagrams/characteristic curves

Other orifices upon request.

Symbols/Circuit diagrams

Type LFA . D…X**

Dimensions

Notice:

• The tightening torques stated are guidelines when using screws with the specified friction coefficients and when using a manual torque wrench (tolerance ± 5 %).

• The specified tightening torques were calculated with total friction coefficient μ = 0.09 … 0.14; adjust in case of modified surfaces.

Installation bore and connection dimensions according to ISO 7368

Notice:

The dimensions are nominal dimensions which are subject to tolerances.

Notices:

• The specified tightening torques stated are guidelines when using screws with the specified friction coefficients and when using a manual torque wrench (tolerance ± 10%).

• The specified tightening torques were calculated with total friction coefficient μtotal = 0.09 ... 0.14; adjust in case of modified surfaces.

• Supplied mounting screws are only suitable for direct assembly on a block. If an intermediate cover is used, mounting screws have to be designed accordingly longer.

Mounting screws (included in the scope of delivery)

Information

Additional functions with special numbers (upon request)

Orifice symbol

Orifice symbol		Ordering code
A**		A**		This orifice is designed as screw-type orifice. If an orifice is to be installed, the respective code letter with the orifice Ø in 1/10 mm has to be entered in the type designation. Example: A12 = Orifice with Ø1.2 mm in channel A.
Ø1,2				This orifice is designed as bore. No specifications are made in the type designation. (Orifice Ø in mm)
Z12				This orifice is designed as screw-type orifice. This is a standard orifice. No specifications are made in the type designation. (Orifice Ø in 1/10 mm)

Accessories

Orifice selection

Downloads

2-way cartridge valves, directional functions Data Sheet | RE21010 | 2017-05-01 | English | PDF | 3.2MB Product Groups: Logic elements - directional function Type LC (cartridge valves), type LFA (control cover)