Shell boilers - Part 4: Fabrication, inspection and acceptance
1 Scope
This document specifies the basic requirements, marking, material cutting and straightening, cold and hot forming, fabrication and assembly of main parts and components, expansion, welding, heat treatment, inspection and test, painting and packing, nameplate and end-of-manufacturing data in the fabrication process of shell boilers.
This document is applicable to the fabrication, inspection and acceptance of shell boilers defined in GB/T 16508.1.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions 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 1804 General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications
GB/T 2652 Tensile test methods on weld and deposited metal
GB/T 2900.48 Electrotechnical terminology of boilers
GB/T 3375 Welding terminology
GB/T 4863 General terminology of machine-building technology
GB/T 16507.5 Water-tube Boilers - Part 5: Fabrication
GB/T 16507.6 Water-tube Boilers - Part 6:Inspection, testing and acceptance
GB/T 16508.1 Shell boilers - Part 1: General requirements
GB/T 16508.2 Shell boilers - Part 2: Materials
GB/T 16508.3 Shell boilers - Part 3: Design and strength calculation
GB/T 30583 Specification for post weld heat treatment of pressure equipment
JB/T 3223 Welding material quality management specifications
NB/T 47013 (All parts) Nondestructive testing of pressure equipments
NB/T 47014 Welding procedure qualification for pressure equipment
NB/T 47015 Welding specification for pressure vessels
NB/T 47016 Mechanical property tests of product welded test coupons for pressure equipment
NB/T 47018 (All parts) Technical permission of welding materials for pressure equipment
NB/T 47030 Specification of high frequency resistance welded spiral fin tubes for boiler
NB/T 47043 Technical specification for manufacture of boiler steel structures
NB/T 47055 Painting and packing specification of boiler
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2900.48, GB/T 3375, GB/T 4863 and GB/T 16508.1 as well as the following apply.
3.1
cold forming
plastic deformation processing at a temperature of lower than the recrystallization temperature of the workpiece metal
Note: In engineering practice, the plastic deformation processing conducted at room temperature is usually referred to as cold forming; and that above the room temperature to the recrystallization temperature is referred to as warm forming.
3.2
hot forming
plastic deformation processing conducted above the recrystallization temperature of the workpiece metal
3.3
tube forming
tube processing such as bending, upsetting, necking and flaring
3.4
hydrostatic test pressure
pressure applied to the whole boiler or pressure components (elements) as required in hydrostatic test
4 Basic requirements
4.1 The raw materials for boilers shall meet the requirements of GB/T 16508.2 and design drawings.
4.2 The structure design and strength calculation of boiler pressure elements shall meet the requirements of GB/T 16508.3.
4.3 The design and fabrication process documents shall be consistent with the production conditions of the unit.
4.4 Appropriate process and method shall be adopted for the fabrication of pressure elements without introducing any additional stress and harmful defects that affect safety and use.
5 Marking
5.1 General requirements
5.1.1 The boiler fabrication unit shall prepare guidance documents for the use of material marking of pressure elements and main load-bearing members, welder marks during fabrication, non-destructive testing marks, product part and component identification numbers and inspection status marks, etc.
5.1.2 The material marking of boiler pressure elements [shell, header, tubing, centralized downcomer, boiler furnace, reversal chamber, seal head (tube plate), top of boiler furnace, footring and tubes, etc.] and load-bearing non-pressure elements (supports and braces) shall be easy to identify, so as to prevent materials from being mixed.
5.1.3 Materials for pressure elements and main load-bearing members shall be subjected to marking transplantation before cutting and blanking for easy identification.
5.1.4 Welder marks, non-destructive testing marks and material marks requiring traceability shall be retained as permanent marks. If the marks are covered during production or lost due to processing, the marking transplantation shall be conducted.
5.1.5 For boilers delivered as bulk items, product marks shall be marked on the seal heads, end caps or drums of the main pressure elements.
5.2 Marking method
5.2.1 The following marking methods or a combination of the following methods should be used:
a) marking with steel seal (low stress steel seal);
b) vibration etching or etching by other tools;
c) painting or marking with a marker;
d) other marking methods that do not damage the boiler safety (such as labeling, etc.).
5.2.2 Steel seal marks shall not be used under the following conditions:
a) stainless steel tube;
Foreword i
Introduction iv
1 Scope
2 Normative references
3 Terms and definitions
4 Basic requirements
5 Marking
6 Material cutting and straightening
7 Cold and hot forming
8 Fabrication and assembly of main parts and components
9 Expansion
10 Welding
11 Heat treatment
12 Inspection and test
13 Painting and packing
14 Nameplate and end-of-manufacturing data
Annex A (Normative) Welded tube hole of boiler
Annex B (Normative) Technical requirements for fabrication of H-shaped finned tube
Bibliography
