The DZ20-1-30/21YM Type Pilot Operated Sequence Valve is a high-performance hydraulic pressure control valve designed to control the sequential operation of hydraulic actuators in a hydraulic system. Featuring a pilot-operated structure, the valve provides accurate pressure sequencing, stable operation, and reliable pressure control under medium and high-pressure working conditions. It is widely used in industrial hydraulic systems, construction machinery, hydraulic power units, and automation equipment.

Working Principle

The DZ20 pilot operated sequence valve controls the operating sequence of hydraulic actuators according to system pressure. Hydraulic pressure acts on the pilot spool through the internal pilot oil circuit. When the inlet pressure reaches the preset pressure value, the pilot valve opens and actuates the main valve spool, allowing hydraulic oil to flow from port A to port B. This enables the secondary hydraulic circuit or actuator to operate in a controlled sequence.

The “YM” configuration indicates:

• Internal pilot oil supply
• External pilot oil drain
• Optional check valve function for reverse free flow

Product Features

• Pilot-operated structure for stable pressure sequencing
• Accurate pressure control and smooth switching operation
• Suitable for sequence control, unloading, and braking functions
• Fast response and reliable hydraulic performance
• Compact structure and easy installation
• Optional check valve configuration available
• Low noise and long service life
• Suitable for continuous industrial hydraulic applications