Standard No.:	GB/T 30583-2026
English Name:	Specifications for post weld heat treatment of pressure equipment
Chinese Name:	承压设备焊后热处理规程
Professional Classification:	GB    National Standard
Source Content Issued by:	SAMR, SAC
Issued on:	2026-01-28
Implemented on:	2026-8-1
Status:	to be valid
Superseding:	GB/T 30583-2014 Specification for Post Weld Heat Treatment of Pressure Equipment
Target Language:	English
File Format:	PDF
Word Count:	26500 words
Translation Price(USD):	795.0
Delivery:	via email in 1~8 business day

GB/T 30583-2026 Specifications for post weld heat treatment of pressure equipment English, Anglais, Englisch, Inglés, えいご This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered. ICS CCS National Standard of the People's Republic of China ‌GB/T 30583-2026 Specifications for post weld heat treatment of pressure equipment 承压设备焊后热处理规程 Issue date: 2026-01-28 Implementation date: 2026-08-01 Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China the Standardization Administration of the People's Republic of China Contents Foreword Introduction 1 Scope 2 Normative references 3 Terms and definitions, symbols 4 Basic process 5 Equipment, instruments and temperature measuring devices 6 Technical preparation 7 Heating and temperature control 8 Temperature measurement 9 Holding 10 Post weld heat treatment report 11 Evaluation of heat treatment effectiveness Annex A (Informative) Diagrams of post weld heat treatment thickness (δ_PWHT) Annex B (Informative) Single heating local post weld heat treatment Annex C (Informative) Main and auxiliary heating local post weld heat treatment Annex D (Normative) Measuring method of the effective heating zone of heat treatment furnace Annex E (Informative) Record form for whole post weld heat treatment of pressure equipment Annex F (Informative) Calculation for field local post weld heat treatment construction Annex G (Informative) Test methods for evaluating the effectiveness of post weld heat treatment Annex H (Informative) Example of evaluation report for post weld heat treatment effectiveness Bibliography Post weld heat treatment procedure for pressure equipment 1 Scope This document specifies the requirements for the basic process, equipment, instruments and temperature measuring devices, technical preparation, and operations such as heating, temperature control, temperature measurement and holding during post weld heat treatment of pressure equipment. This document applies to the post weld heat treatment of boilers and pressure vessels (excluding gas cylinders). Other pressure equipment may refer to this document. 2 Normative references The contents of the following documents constitute essential provisions of this document through normative reference. For dated references, only the edition cited applies. For undated references, the latest edition (including all amendments) applies. GB/T 3375 Welding terminology GB/T 9452 Measuring method of the effective heating zone of heat treatment furnace GB/T 4989 Compensating cables for thermocouples GB/T 4990 Alloy wires for compensating cables for thermocouples NB/T 47014 Welding procedure qualification for pressure equipment 3 Terms and definitions, symbols 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 3375, GB/T 9452 and the following apply. 3.1.1 weldment A welded pressure equipment or its components. 3.1.2 post weld heat treatment; PWHT The process of uniformly heating a weldment to a sufficiently high temperature, holding it for a certain period of time, and then uniformly cooling it, in order to eliminate welding residual stress and improve the structure and properties of the welded joint. 3.1.3 local post weld heat treatment Post weld heat treatment carried out by local heating when whole heat treatment cannot be performed due to dimensional limitations, special structural constraints, repair, rework, modification, etc. 3.1.4 soak band; SB During local post weld heat treatment, the bandshaped area on the weldment, covering the weld and both sides thereof, that reaches the specified temperature range. NOTE: The soak band generally covers at least the weld zone, the heataffected zone and the adjacent base metal. 3.1.5 heated band; HB During local post weld heat treatment, the area that is heated to ensure that the weldment obtains the specified soak volume range. 3.1.6 gradient control band; GCB During local post weld heat treatment, the area where thermal insulation material is applied to the surface to control the temperature gradient and prevent heat dissipation from the heated range and the soak range of the weldment. NOTE: The gradient control band is also referred to as the "insulation band". 3.1.7 holding temperature The specified temperature range maintained for a certain period of time in the weldment or its local soak area to achieve the purpose of post weld heat treatment. 3.1.8 holding time The duration for which the weldment or its local soak area is maintained at the holding temperature. This period begins when the temperatures at all temperature measurement points have uniformly reached the minimum holding temperature, and ends when the temperature at any temperature measurement point falls below the minimum holding temperature for the first time. 3.2 Symbols The following symbols apply to this document. A1−3A1−3​ — Plastic coefficient, obtained by calibration test, in newton metres (N·mm); AC1AC1​ — The lower transformation point of a metal, which is the temperature at which austenite begins to form when steel is heated, in degrees Celsius (°C); NOTE: Also referred to as the "heating transformation point" and "lower transformation point" or "lower critical point". 4 Basic process 4.1 General requirements 4.1.1 In addition to complying with the provisions of this document, the post weld heat treatment of pressure equipment shall also meet the requirements of relevant product standards, design documents and contracts. 4.1.2 Apart from this document, any post weld heat treatment process that has been proven effective through test research and/or practice may be used for the post weld heat treatment of pressure equipment in the unit after confirmation through negotiation between the supplier and the purchaser. 4.1.3 The post weld heat treatment temperature for nonalloy steels and lowalloy steels shall not exceed the lower transformation point (Ac₁) of the metal. Austenitic stainless steels, duplex steels and nickelbased alloys may be heated to the solution temperature or the stabilisation treatment temperature. 4.1.4 Heat treatment of nonalloy steel and lowalloy steel components below 490 °C, and heat treatment of highalloy steel (Fe6, Fe7, Fe8, Fe10I, Fe10H, Fe11A) components below 315 °C, shall not be regarded as post weld heat treatment. 4.1.5 Post weld heat treatment operators shall be qualified through training and assessment before taking up their posts. 4.1.6 Heat treatment technicians shall possess certain professional knowledge and practical experience. After mastering the following basic information, they shall prepare the corresponding post weld heat treatment procedure specification for each weldment: a)The weldability of the steel and welding materials used for the weldment and their adaptability to post weld heat treatment; b) The actual tempering temperature of the steel and the post weld heat treatment conditions for the deposited metal mechanical properties test piece; c) The provisions of the weldment design documents, service requirements and manufacturing process; d) The post weld heat treatment environment, post weld heat treatment method, equipment, device characteristics and procedures. 4.1.7 Post weld heat treatment shall be carried out after welding repair and before pressure testing. 4.1.8 When conditions permit, whole post weld heat treatment shall be given priority. 4.2 Post weld heat treatment thickness (δPWHT)