Double Speed Buffer-type Four Valve (JL89)

This is a new hydraulic elevator control valve without VFD to control the elevator. It operates stably,  reliably, and precisely even under extreme loads and large temperature fluctuations, featuring  simple operation and commissioning. The combination of lifting control valves and pilot-operated  control valves ensures stable elevator operation and accurate landing level position. The elevator achieves stable high-speed operation at 0.35 m/s, with a load capacity of 1000 kg. The innovative addition of the SRV function resolves the issue of steel wire ropes/steel belts  coming off the rollers when they become loose during elevator installation and maintenance.

Ascend 

The acceleration and deceleration process during ascent is controlled by dual  pilot-operated control valves.  

• After the motor starts, coils A and B of the pilot-operated control valves are  energized, and the elevator begins to accelerate uniformly to a set speed.  

• When the elevator reaches the preset deceleration point, coil B is de-energized,  causing the elevator to decelerate uniformly to a lower speed. 

• Upon arriving at the landing position, coil A is de-energized, and the motor  stops operating after a delay of 1.5 to 2.5 seconds.

Descend

The descending process is controlled by dual pilot-operated  control valves for acceleration control. When the lift receives a descending signal, coils C and D are  energized simultaneously, and the lift begins to descend  with uniform acceleration. Upon reaching the preset  deceleration position, coil C is de-energized, and the lift  decelerates uniformly to a slow speed. When it arrives at the  leveling position, coil D is de-energized.