GB 16749-1997Bellows expansion joints for pressure vessel (English PDF)

4.1 General

4.1.1 The design, manufacture, inspection and acceptance of the wave expansion joint of the pressure vessel shall comply with the provisions of this standard, and shall also comply with the relevant regulations promulgated by the State.

Laws, regulations and safety technical specifications.

4.1.2 The use of aluminum, titanium, nickel and nickel alloys, zirconium and other metal pressure vessel expansion joints, its design, manufacture, inspection and acceptance delimiter in addition to the provisions of 4.1.1, the corresponding requirements of JB/T 4734, JB/T 4745, JB/T 4756, and NB/T 47011 should also be met.

4.1.3 The design and manufacturing unit of the wave expansion joint should establish a sound quality management system and operate effectively.

4.1.4 The wave expansion joints within the jurisdiction of TSG21-2016 shall be subject to the supervision of the special equipment safety supervision agency.

4.1.5 Wave expansion joints that cannot be designed and calculated in accordance with this standard and the corresponding reference standards may be in accordance with 4.1.6 of GB/T 150.1-2011.

The prescribed method is designed.

4.2 Qualifications and responsibilities

4.2.1 Qualification

The wave expansion joints within the jurisdiction of TSG21-2016 shall have the following qualifications for the manufacturing unit and personnel.

a) The wave expansion joint manufacturing unit shall hold the corresponding special equipment manufacturing license. Establish expansion according to TSG21-2016 requirements Quality assurance system and management system and effective operation, the manufacturing unit and its main person in charge should cope with the pressure vessel expansion the manufacturing quality of the festival is responsible.

b) The welding operator of the wave expansion joint (referred to as the welder) shall obtain the quality and technical supervision department according to the provisions of TSG21-2016.

After the "Special Equipment Operator Certificate" of the corresponding project is issued, the welding work within the scope of the qualified project can be performed within the valid period.

c) Non-destructive testing personnel of the wave expansion joint shall obtain the corresponding certificates issued by the quality and technical supervision department in accordance with the provisions of TSG21-2016.

After the qualification certificate, the non-destructive testing work corresponding to the type and technical level of the qualification certificate can be undertaken.

4.2.2 Responsibilities

4.2.2.1 Responsibilities of the user or design client

The user or design client of the wave expansion joint shall submit the design conditions of the wave expansion joint to the design unit in formal written form. Design strip the pieces include at least the following.

a) Main standards, specifications and design parameters (including design pressure, design temperature, nominal diameter, design) based on the design of the wave expansion joint Displacement and material requirements);

b) Operating parameters of the wave expansion joint (including working pressure, working temperature, medium composition and characteristics, working displacement and operating fatigue times) number);

c) Other conditions required for the design.

4.2.2.2 Design unit (department) responsibilities

The responsibilities of the design unit (department) shall comply with the following provisions.

a) The design unit (or department) and the principal responsible person shall be responsible for the design quality of the wave expansion joint, and the integrity and positiveness of the design documents.

Responsible for authenticity;

b) The design file of the wave expansion joint shall include at least the design calculations, design drawings, and manufacturing technical conditions (including inspection and test).

Seek), if necessary, installation and use of maintenance instructions;

c) The design unit (or department) should consider the failure mode that may occur during the use of the wave expansion joint, and propose to prevent failure.

Measures, when necessary, to issue a risk assessment report to the user (when relevant standards or design client requests);

d) The design unit (or department) shall maintain all design documents within the design life of the wave expansion joint.

4.2.2.3 Manufacturing unit responsibilities

The responsibilities of the manufacturing unit shall comply with the following provisions.

a) It should be manufactured according to the requirements of the design documents. If the original design needs to be modified, it should be written in the agreement of the original design unit.

Documents and detailed records of the changes;

b) A sound quality plan should be developed prior to manufacture, including at least manufacturing process control points, inspection items and qualification indicators;

c) Possible failure modes and preventive measures proposed in the waveform expansion section risk assessment report issued by the design unit (or department) Reflected in the product quality certification document;

d) The quality inspection department of the manufacturing unit shall, in the manufacturing process of the wave expansion joint and after completion, be in accordance with this standard, the drawing requirements and the quality plan.

It is required to carry out various inspections and tests on the wave expansion joints, issue corresponding reports, and be responsible for the correctness and completeness of the report;

e) At least one of the following technical documents shall be kept for each waveform expansion joint product for the design life.

1) Quality plan;

2) manufacturing process drawings or manufacturing process cards;

3) Product quality certification documents;

4) Material quality certification documents and material tables;

5) Welding process and heat treatment process documentation;

6) Inspection, and test records during and after the manufacturing process;

7) Original design drawings and as-built drawings of the expansion joints.

4.3 Welding joint classification and welded joint coefficient

4.3.1 Welding joint classification

4.3.1.1 Expansion Joints The welded joints between the pressure components are divided into four categories. A, B, C, and D, as shown in Figure 1. The welded joints are classified as follows.

a) longitudinal butt joints of bellows, end pipes (including ferrules and stiffeners) longitudinal butt joints, splitting all longitudinal splicing joints, all belong to Class A welded joints;

b) Circumferential butt joints of bellows and end pipes (or equipment casings) (plug welded butt joints, end welded butt joints, straight sides of bellows) the grooved butt joint of the segment insert/coat (see welding type 3, type 4, type 5 in Table 1), the bellows is connected to the bellows the circumferential butt joint, the end pipe and the circumferential joint of the equipment casing are all B-type welded joints;

c) angular joints, ferrules, stiffeners and bellows or end pipes of the straight section of the bellows and the end pipe (or equipment casing) the housing is connected to the angular joint (see welding type 1, 2 in Table 1), and the flange is connected to the end tube (or equipment housing).

Is a Class C welded joint;

d) The flange and the bellows, the joint connecting the end pipe and the head are all Class D welded joints.

4.3.1.2 The welded joint of the non-pressurized component and the pressed component is an E-type welded joint, as shown in Figure 1.

Description.

1---end plate;

2--- bellows;

3---end tube (or device housing);

4---flange;

5---plug (flange);

6---support ring;

7---liner;

8---outer sheath.

Figure 1 Welding joint classification

4.3.1.3 The connection between the straight side of the bellows and the end pipe (or equipment housing) and the welded joint are shown in Table 1.

Table 1 Corrugated pipe straight edge and end pipe (or equipment shell) joint weld

Serial number

Welding type

Usual design

Variant (allow A~D combination) Bogan Reinforced Hoop Accessory Hoop ABC (single) D (two) Coat/fillet weld Interpolation/fillet weld Coat/bevel weld Interpolation/groove weld Butt weld - -the connecting member on the opposite side of the pressure side of the bellows and the side of the ferrule that is in contact with the bellows and the straight side section should be rounded or chamfered.

Corrugated pipe joint welds with ferrules shall comply with.

--- If it is a fillet weld, the weld height "a" should conform to the formula. a >= 0.7 nt;

--- If the length of the straight section of the bellows is Lt >= 0.5 ntDb, it is recommended to set the ferrule;

---The ferrule should be fixed axially by welding or mechanical means.

Note. For the insert (or jacket) groove weld joint (welding type 3, type 4), refer to GB/T 3375 lock bottom butt joint (V-shaped groove).

4.3.2 Welded joint coefficient

4.3.2.1 The welded joint coefficient phi shall be determined according to the weld form of the butt joint and the length ratio of the non-destructive test. Subscripts b, c, f, p and r Representing bellows, ferrules, fasteners, tubes and reinforcement materials, respectively;

4.3.2.2 The welded joint coefficient of the steel pressure vessel expansion joint is selected according to Table 2.

Table 2 Welding joint coefficient phi

Welding joint form, non-destructive testing, local non-destructive testing Double-sided welded butt joint and full penetration butt joint equivalent to double-sided welding 1.0 0.85 Single-sided butt joints along the entire length of the weld without a backing plate - 0.70

4.3.2.3 The welded joint coefficient of non-ferrous metals such as aluminum, titanium, nickel, zirconium and their alloys is in accordance with JB/T 4734, JB/T 4745, JB/T 4756, NB/T 47011 related regulations.

4.3.3 Welding joint high temperature strength reduction coefficient

4.3.3.1 Scope of application

The high-strength strength reduction coefficient w of the welded joint is suitable for the design temperature >= 510 °C, due to the long-term effect of continuous load such as internal pressure.

The high-strength strength of the welded joint is lower than that of the base metal, so in the design calculation of Chapter 7, the bellows and the reinforcing member that are subjected to the internal pressure are caused.

The circumferential film stress should satisfy the allowable stress [sigma]t and the longitudinal welded joint coefficient phi product phi[sigma]t, and should also be multiplied by the high temperature drop of the welded joint.

The low coefficient w is phi[sigma]tw.

4.3.3.2 W selection rules

w Use the following rules.

a) welded joint high temperature strength reduction coefficient w, see Table 3;

b) For materials other than Table 3, when the design temperature is not higher than 510 °C, take w=1; when the design temperature is 815 °C, take w=0.5;

The inter-temperature value is calculated by the difference method w; when the design temperature is higher than 815 ° C, the designer determines w;

c) Exceeding one of the following conditions, excluding the welded joint high temperature strength reduction factor w.

1) Below creep temperature, for CrMo steel, tough ferritic heat resistant steel, 300 series austenitic stainless steel, 800 nickel base the long-term working strength of gold and 600 nickel-base alloy welded joints is not lower than the strength of the base metal;

2) The lower limit of allowable stress, yield strength and tensile strength of the bellows material at all temperatures is in accordance with TSG21-2016.

GB/T 150-2011 and corresponding material standards; material design temperature range does not exceed the allowable temperature of steel;

3) The bellows welded joint is a full penetration structure, the welding material meets the requirements of the welding material standard and this standard, and the weld metal is guaranteed.

Tensile properties, impact properties or other properties are not lower than the lower limit specified in the parent metal standard, and comply with TSG21-2016, GB/T 150-2011 regulations;

4) Design pressure and design temperature fluctuations do not exceed the design range.

Table 3 welded joint high temperature strength reduction coefficient w

material

Temperature/°C

427 454 482 510 538 566 593 621 649 677 704 732 760 788 816 CrMo steel a~c 1 0.95 0.91 0.86 0.82 0.77 0.73 0.68 0.64 - - - - - -CSEF(NT)c~e - - - 1 0.95 0.91 0.86 0.82 0.77 - - - - - -CSEFc, d(PWHT) - - 1 0.5 0.5 0.5 0.5 0.5 0.5 - - - - - -Metal-free 300 series austen Stainless steel and 800 nickel base alloy and 600 nickel base Gold self-welding f - - - 1 1 1 1 1 1 1 1 1 1 1 1 Filled metal 300 series austen Stainless steel and 800 nickel base alloy - - - 1 0.95 0.91 0.86 0.82 0.77 0.73 0.68 0.64 0.59 0.55 0.5 the temperature listed in this table is only used for the high-temperature strength reduction coefficient w of the welded joint of the corresponding material, and the upper limit of the use temperature of the material is in accordance with GB/T 150.2-2011.

The provisions of the material standards.

The...