GB/T 34663-2017 in English

Analysis of the core content of the standard

1. Scope of application and explosion-proof type

This standard applies to Class II metal shell resistance heaters, with a rated voltage of ≤1140V, and explicitly excludes medical equipment and external heating devices. Mainly regulate three types of explosion-proof:

2. Key structural requirements

2.1 : Shell design

• Material restrictions: The content of aluminum/magnesium/titanium/zirconium must comply with the requirements of GB3836.1-2010
• Thickness standard: The thickness of the flameproof shell must be ≥1.7mm (steel) or 3.2mm (aluminum), see standard Table 1 for details
• Special treatment: The roughness of the joint surface Ra≤6.3μm, and the use of gaskets is prohibited

2.2 Temperature protection system

3. Comparison of core test items

4. Implementation suggestions

1. Selection guide: For Class IIC environment, copper alloy housing (copper content ≤30%) is preferred
2. Installation points: The cable entry device must pass the 20kg·6h clamping test (5.3.2)
3. Maintenance requirements: The static strength of the housing must be re-inspected every 3 years (Appendix A.4)

5. Technology evolution analysis

Compared with the previous version, this standard has the following main enhancements:
1) IntroducingSelf-limiting temperature characteristics verification requirements (clause 3.25)
2) Added low liquid level protection clause for liquid heaters (4.6.2)
3) Clarified the double inspection rules for composite equipment (Table 5 + Table 6)