R900587346 DB20-1-5X/315 Overflow valve imported from Germany by Rexroth

FAQ:

Q1: What is the core function and design principle of the Rexroth DB20-1-5X/315 valve?

A:​ It is a two-stage, pilot-operated pressure relief valve. Its core purpose is to limit the maximum system pressure​ with high precision and stability. It functions as a critical safety device, opening to divert flow to the tank when the preset pressure is reached, thereby protecting pumps, actuators, and other components from damage due to overpressure. The pilot-operated design ensures minimal pressure override and stable operation even at high flows.

Q2: What is the key difference between the DB20-1-5X/315 and the DB20-1-5X/200?

A:​ The key difference is the maximum adjustable pressure setting, indicated by the suffix. The DB20-1-5X/315​ has a maximum setting of 315 bar, while the DB20-1-5X/200​ is limited to 200 bar. All other core specifications like port size (G1/2"), design, and approximate flow capacity are generally the same within the DB20-1-5X series. The choice depends on the required system pressure limit.

Q3: How is the pressure adjusted, and how is the setting maintained?

A:​ The pressure is adjusted manually via a calibrated adjustment screw. Turning the screw changes the compression of the pilot spring, which sets the cracking pressure. The valve typically includes a locking mechanism​ (such as a locknut) to secure the setting and prevent it from drifting due to vibration or accidental contact once the desired pressure is set.

Q4: In a hydraulic system, where should this valve be installed, and what is the correct port configuration?

A:​ It is typically installed in the main pressure line, directly after the pump, to protect the entire system. The correct port configuration is:

• P (Pressure Port):​ Connected to the pressure line from the pump/system.

• T (Tank Port):​ Connected directly to the hydraulic tank (reservoir).

• Control Line (X, if present):​ For remote control or drain; consult the specific schematic for the DB20-1-5X/315.

Q5: What are the main advantages of using a pilot-operated relief valve like the DB20 series over a direct-acting type?

A:​ The primary advantages are:

1. High Accuracy & Low Override:​ Maintains a nearly constant pressure over a wide flow range with minimal difference between cracking and full-flow pressure.

2. High Flow Capacity:​ Can handle large flows (e.g., ~120 L/min) in a relatively compact size.

3. Stable Operation:​ Less prone to chatter, instability, or pressure spikes, especially at high flows.

4. Energy Efficiency:​ Reduced pressure override means lower power loss and heat generation in the system compared to some direct-acting valves.