GB/T 25151.6-2014Fabrication and inspection method for high pressure urea equipment - Part 6: Helium leakage test method for urea high pressure equipment (English PDF)

1 Scope

This section GB/T 25151 specifies the urea plant in the backing layer of welded joints urea high pressure equipment, tube to tube sheet welding tags

Helium leak test methods for head Have penetration defects.

This section applies to the urea synthesis column, stripper CO2 urea, urea, high-pressure washer, urea, urea and other high-pressure condenser high-voltage equipment

Helium leak test.

Helium leak test other chemical equipment may be performed with reference to this section.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein

Member. For undated references, the latest edition (including any amendments) applies to this document.

GB 150.4 Pressure Vessels Part 4. fabrication, inspection and acceptance

GB/T 9842 urea reactor technical conditions

GB/T 9843 urea high pressure scrubber technical conditions

GB/T 10476 technical conditions of urea high-pressure condenser

GB/T 12604.7 Terminology for nondestructive testing Leak Detection

HG/T 2952 urea carbon dioxide stripper technical conditions

JB/T 4730.5 Non-destructive testing of pressure equipments - Part 5. penetrant testing

3 Terms and Definitions

Terms and definitions GB/T 12604.7 defined apply to this document.

The first four test preparation 4.1 backing layer and the inner member tube to tube sheet welding joints shall be visually examined after all the welding, the weld surface quality should meet

GB 150.4 and GB/T 9842, GB/T 9843, GB/T 10476, HG/T 2952 requirements.

After the completion of the high-pressure equipment manufacturing 4.2 Urea pressure test should be carried out, and then backing layer welded joints, weld tube to tube plate joints

100% penetration testing. Penetrant testing shall comply with JB/T 4730.5 of.

Helium leak test 4.3 urea high pressure equipment should pressure test after passing the detection and penetration.

Prior to 4.4 were Urea high pressure helium leak test equipment, first filled with 5 × 10-2MPa dry air or nitrogen, do tightness test to exclude

Pipe leak detection, pressure gauge fittings, valves, and welded joint backing layer tube to tube sheet welding joints and other large leaks.

All welded joints and tube to tube sheet welding joint surfaces should be cleaned on both sides and 4.5 equipment backing layer, there should be no oil

Grease, dust, water, colored reagent residues, etc., to keep the surface of the subject site dry and clean.