Shijiazhuang Laiye Imort& Export Trading Co., Ltd. is one of the leading manufacturers and suppliers of dz pilot operated pressure sequence valve in China, also supports customized service. If you're going to wholesale high quality dz pilot operated pressure sequence valve made in China, welcome to get pricelist from our factory.
Product Overview
The DZ pilot operated pressure sequence valve is a pressure‑controlled directional valve that allows a secondary circuit to operate only after the primary circuit reaches a preset pressure. Designed for sandwich plate or cartridge mounting, it ensures reliable sequence control without external pilot lines. Every DZ valve leaves our workshop after full pressure‑flow verification – no guesswork, only predictable switching.
Key Technical Parameters
| Parameter | Value |
|---|---|
| Nominal size | NG6 / NG10 (ISO 4401‑03/05) |
| Max. operating pressure (P port) | 315 bar (4565 psi) |
| Max. secondary circuit pressure | 250 bar |
| Flow rating | 40 L/min (NG6) / 80 L/min (NG10) |
| Pressure setting range | 10 – 315 bar (field adjustable) |
| Hysteresis | < 3% |
| Pilot oil drain | External (port Y) or internal (optional) |
| Fluid temperature range | -20°C to +80°C |
| Weight | 1.5 kg (NG6) / 2.8 kg (NG10) |
Products Description
How It Works: Spool Switching & Oil Circuit Control
The valve combines a main spool (normally closed) and a pilot relief‑type control with an external drain.
Sequence operation step by step:
Oil enters port P (primary circuit). The main spool stays closed because pilot pressure is below setting.
As primary pressure rises and reaches the pilot spring setting, the pilot poppet opens slightly.
This allows a small flow to drain via port Y (external drain), creating a pressure drop across the main spool's internal orifice.
The pressure difference pushes the main spool upward – port P connects to port A (secondary circuit).
The secondary actuator starts moving while primary pressure remains at the set value (the valve behaves like a pressure‑regulated bypass).
When primary pressure falls below the setting (e.g., primary actuator reaches its end stop), the pilot poppet closes and the main spool returns, cutting off flow to the secondary circuit.
Spool switching mode – fully hydraulic, pilot‑operated. No solenoid, no manual override. The main spool position depends solely on the pressure difference across it, which is controlled by the pilot relief stage.
Oil control function – Pressure sequence (not flow sequence). The secondary circuit never receives oil until the primary circuit has built enough pressure to perform its work (e.g., clamping before drilling).
Frequently Asked Questions (FAQ)
1. What is the difference between a sequence valve and a pressure relief valve?
A relief valve limits system pressure by diverting flow to tank when the set point is exceeded, and it stays open. A DZ pilot operated pressure sequence valve diverts flow to a secondary circuit once primary pressure reaches the set point – and it can close again when primary pressure drops below the setting.
2. How do I adjust the cracking pressure of the DZ valve?
Loosen the locknut on top of the pilot section. Turn the adjustment screw clockwise to increase the sequence pressure, counter‑clockwise to lower it. One turn typically changes pressure by 25–30 bar (check the scale if provided). After adjustment, retighten the locknut firmly.
3. The valve has an external drain port Y. Can I plug it?
No. The external drain must return to tank with zero backpressure. Plugging it will raise the effective sequence pressure unpredictably and may damage the pilot seal. If your system cannot provide a separate drain line, order the internal‑drain version (code "T" in the model number).
4. Can the DZ valve be used in a vertical mounting orientation?
Yes. The main spool and pilot poppet are spring‑centered, so gravity does not affect switching. However, for vertical applications with high vibration (mobile equipment), we recommend adding a lock washer under the adjustment locknut.
Our production and equipment
40+
years
10000+
containers
20+
countries
One-stop Hydraulic Valve Factory in China
Hot Tags: dz pilot operated pressure sequence valve, China dz pilot operated pressure sequence valve, manufacturers, suppliers, factory
