As a key actuator in industrial automation systems, the regulating valve is widely used in high-risk industries such as oil, chemical, natural gas, and electricity. In these environments, there are a large number of flammable gases or dusts, which are highly prone to explosion accidents once they leak and encounter a fire source. Therefore, the explosion-proof performance test of the regulating valve is particularly important, and it is an essential link to ensure the safe operation of the equipment, protect the safety of personnel, and ensure production stability.
One, The Necessity of Explosion-proof Testing for Control Valves
Explosion-proof control valves are mainly used in explosive hazardous areas, and their design and manufacture must comply with national or international explosion-proof standards (such as GB 3836 series, IEC 60079, etc.). Explosion-proof testing can verify whether the control valve has the ability to prevent explosions caused by electric sparks, high temperatures, etc. under extreme working conditions, ensuring its safe operation in hazardous environments.
Two, Common Explosion-proof Forms and Test Content
The explosion-proof forms of control valves mainly include explosion-proof type (d), intrinsic safety type (i), increased safety type (e), etc., and different types of explosion-proof structures have different test methods and standards.
1. Explosion-proof Type Test
Explosion-proof type control valves prevent the
spread of internal explosion to the outside by enclosing the components that may generate sparks with a sturdy housing. During the test, explosion pressure tests, explosion-proof joint face gap measurements, and housing strength tests are required to verify whether the explosion-proof performance meets the standard.
2. Intrinsic Safety Test
Intrinsic safety type
control valves ensure that sparks or temperatures sufficient to cause an explosion will not be generated even in the event of a fault by limiting the circuit energy. The test includes maximum allowable voltage, current test, spark energy test, thermal effect test, and other tests.
3. Protection Level Test (IP Rating)
Explosion-proof control valves also need to have a certain degree of protection level to prevent dust or water vapor from entering the inside and affecting the performance. The test usually includes dust-proof test, water spray test, and other tests.
4. Temperature Rise Test and Surface Temperature Test
During normal operation and fault conditions, the surface temperature of the valve shall not exceed the ignition temperature of the combustible substances. In the test, an infrared thermal imaging instrument or other temperature measuring equipment is required to record the temperature changes.
5. Aging and Environmental Adaptability Test
Including high and low temperature cycle tests, humidity and temperature tests, vibration and impact tests, etc., simulating the use conditions under extreme environments to verify the stability and safety of the valve under long-term severe working conditions.
Three, Test Process and Standard Basis
Explosion-proof testing is generally carried out by qualified third-party testing institutions, and the test process usually includes:
1. Document Review: Review the
design drawings, technical documents, material lists, and other materials;
2. Prototype Inspection: Confirm that the prototype structure is consistent with the design drawings;
3. Laboratory Testing: Various explosion-proof performance tests are carried out according to the standard;
4. Issue Report: After the test is
passed, the explosion-proof qualification certificate is issued by the testing institution;
5. Type Approval and Certification: Type approval is carried out according
to national or industry requirements, such as ATEX, IECEx, NEPSI, and other certifications.
Four, Conclusion
With the continuous improvement of industrial automation, the application of control valves in hazardous areas is becoming more and more extensive. Therefore, conducting scientific and standardized explosion-proof tests is not only a prerequisite for products to enter the market, but also an important foundation for ensuring industrial safety. Enterprises should attach great importance to the explosion-proof testing of control valves, choose products that meet the standards, and ensure safe and reliable operation in high-risk environments.
