Mobile cranes

Double check valves in cartridge design can be screwed directly into the outrigger cylinder. The valve provides protection against a load dropping in the event of a line break in the supply lines. The valves are designed as pilot-operated valves. Hardened components (seat and cone) guarantee zero leakage in the rest position and a long service life. The valve is suitable for up to max. 70 lpm and can withstand pressures up to 500 bar. A screw-in housing is available for the valve.

The newly developed MotionOne lowering brake valve is suitable for motor-cylinder applications and is the right choice when it comes to precisely controlling and positioning high loads with up to 600 l/min. The modular design with various control options ensures maximum flexibility during commissioning. The MotionOne is suitable for applications with low to high vibration susceptibility. The newly developed damping cartridge is particularly suitable for applications with high vibration susceptibility. In accordance with the modular system, users can essentially choose between a standard cover with and without pressure relief valve, electrical proportional control, or the newly developed damping cartridge for the MotionOne.

Controlling the slewing gear of a mobile crane or similar equipment with a long boom places special demands on valve technology due to high torques combined with high mass inertia and potential sensitivity to external forces (e.g., wind). To offer an optimal solution for all operating conditions, the use of a valve with separate control edges for the inlet and outlet of both slewing gear motor sides is recommended. The valve is designed for an LS-controlled pump; the inlet flow is directed via the inlet spool to the motor and from there via the outlet spool to the tank. These are pilot-operated valves, which can only be actuated after being enabled by a switching valve. The consumer sides each feature pressure-replenishing valves, ensuring that neither overload nor cavitation is possible. The inlet and outlet spools are matched to each other with their characteristic curves. Since they can be controlled separately, optimal strategies can be implemented for every operating situation. These include free positioning over a load, clamping the boom, or slow braking with a defined characteristic. The mechanical brake can also be released via the valve. With this valve, flow rates of up to 120 l/min are controllable.

When lowering the boom, the load pressure acting on the hose burst valve increases. With standard hose burst valves, the higher pressure difference leads to an increase in lowering speed. With Type 3E, the increase in load pressure is detected, and the lowering speed is automatically reduced under high loads. This hose burst valve can be controlled hydraulically proportionally or electrically proportionally.

For telescoping a mobile crane, it is important to be able to position very precisely, while also achieving high travel speeds with low pressure loss. Wessel-Hydraulik offers special spool configurations from the LHB-4N and -4K series for this purpose.

The FDV-CA type flow divider valve divides a flow rate into two fixed partial flows, independent of pressure conditions. The division ratio is predetermined by design. A wide variety of division ratios are available ex works. Flow through the valve always occurs from C to A and B. The valve is available both as a cartridge and as a complete valve with housing. The valve is suitable for steering systems, for example.

The PRV-DSU pressure relief valve is a direct-acting, robust valve for small flow rates up to 10 l/min. The valve can withstand up to 500 bar and is delivered pre-set. This valve is suitable, for example, for lifting cylinders in mobile cranes. Too high load pressure, which can be caused by the sun heating up the cylinder, is prevented with this valve.

The valve is installed in the return line directly upstream of the tank inlet. The oil flowing back from the consumers is preloaded and is thus available for make-up functions and the prevention of cavitation. The valve is available with various preload pressures (3 bar, 4.5 bar). Specific housings adapted to customer requirements are possible.