DA08 Cryogenic Safety Valves for Dewar Bottle Gas Cylinders Brass

| Overview

The DA08 series brass cryogenic safety valve is a protective device used for various cryogenic insulated gas cylinders or pipelines, serving as a pressure relief mechanism for container pressure protection. It is primarily used on cryogenic gas cylinders. When the internal medium pressure of the pipeline or container exceeds the set value, the valve automatically opens to discharge the medium, and automatically closes and resets when the pressure drops back.

| Working Principle

This is a spring-loaded safety valve. When the pressure generated by the medium inside the pipeline or container gradually approaches the spring force, the sealing surface loses balance and begins slight leakage. As the internal pressure continues to rise, the disc reaches full opening height for complete discharge. As the fluid is expelled, internal pressure gradually decreases. When the spring force exceeds the force generated by the internal medium, the disc is pressed back onto the seat by the spring and the valve closes.

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 Factory Shoot

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 Application Video

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 Product parameters

| Data Sheet

1: What media is the DA08 safety valve suitable for? Is it compatible with oxygen?

A:  Suitable for LNG, LO2, LN2, LAr, liquid CO2 and other cryogenic gases and liquids. It can be used with oxygen media, but the valve body must undergo strict degreasing and de-oiling treatment before installation, otherwise there is a risk of explosion.

2: How to select among different sub-models (DA-08 / DA-08A1~A4)?

A: The sub-models differ only in set pressure (0.8~3.9 MPa); external dimensions are identical. Select the corresponding set pressure level based on the maximum allowable working pressure of the container or pipeline. Generally, set pressure = vessel maximum operating pressure × 1.05~1.10.

3. What should I do if the safety valve leaks?

A:Three common causes:

1. Impurities trapped on the sealing surface → Disassemble, clean, and purge;

2. Set pressure too close to operating pressure → Slightly increase set pressure;

3. Spring relaxation after long-term use → Calibrate and replace the spring.

4. How to handle frequent chattering of the safety valve?

A: Check capacity selection: whether the rated discharge capacity far exceeds actual demand;

    Check inlet pipe diameter: whether it is too small or too long causing excessive flow resistance;

    Check discharge back pressure: whether discharge pipe resistance exceeds the limit (should be <10% of set pressure).

5. How often does the DA08 safety valve need to be calibrated?

A: At least once a year is recommended. For frequent opening/closing or highly corrosive media conditions, calibration every six months is advised. Calibration items include set pressure, sealing performance, and blowdown (opening/closing differential).