CJ/T 402-2012 in English

Bellows expansion joints for city heating pipeline

1 Scope

This standard specifies the terms and definitions, classification and designation, requirements, test methods, inspection rules, and marking, packaging, transportation and storage of bellows expansion joints for city heating pipeline.

This standard is applicable to the manufacture and inspection of bellows expansion joints for city heating pipeline with design pressure less than or equal to 2.5 MPa and design temperature less than or equal to 350 °C.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 699 Quality carbon structure steels
GB/T 700 Carbon structural steels
GB/T 985.1 Recommended joint preparation for gas welding, manual metal arc welding, gas-shield arc welding and beam welding
GB/T 1591 High strength low alloy structural steels
GB/T 3077 Alloy structural steels
GB/T 12777-2008 General specification for metal bellows expansion joints
JB 4730.2-2005 Nondestructive testing of pressure equipment - Part 2: Radiographic testing
JB 4730.3-2005 Nondestructive testing of pressure equipment - Part 3: Ultrasonic testing

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

3.1
directly buried bellow expansion joint
bellow expansion joint directly buried in soil to compensate thermal displacement of pipeline

3.2
single action bellow expansion joint
bellow expansion joint only used to compensate the displacement of directly buried pipeline during preheating, and then welded into a whole to bear the pipeline load

3.3
minimum number of grading for compensation quantity
minimum grade of designed compensation quantity of bellow expansion joint available to the user within the specified maximum designed compensation quantity

4 Classification and designation

4.1 Classification

Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Classification and designation
5 Requirements
6 Test methods
7 Inspection rules
8 Marking, packaging, transportation and storage
Annex A (Normative) Single action bellow expansion joint