ASME B31.3-2010 Code Requirement

ASME B31.3 -2010 RQUIREMENTS

fluid service: a general term concerning the application of a piping system, considering the combination of fluid properties, operating conditions, and other factors that establish the basis for design of the piping system. See Appendix M.

(a) Category D Fluid Service: a fluid service in which all the following apply: (1) the fluid handled is nonflammable, nontoxic, and not damaging to human tissues as defined in para. 300.2 (2) the design gage pressure does not exceed 1035 kPa (150 psi). (3) the design temperature is from −29°C (−20°F) through 186°C (366°F).

(b) Category M Fluid Service: a fluid service in which the potential for personnel exposure is judged to be significant and in which a single exposure to a very small quantity of a toxic fluid, caused by leakage, can produce serious irreversible harm to persons on breathing or bodily contact, even when prompt restorative measures are taken.

(c) Elevated Temperature Fluid Service: a fluid service in which the piping metal temperature has a design or sustained operating temperature equal to or greater than Tcr as defined in Table 302.3.5, General Note (b).

(d) High Pressure Fluid Service: a fluid service for which the owner specifies the use of Chapter IX for piping design and construction;

see also para. K300.

(e) Normal Fluid Service: a fluid service pertaining to most piping covered by this Code, i.e., not subject to the rules for Category D, Category M, elevated temperature, or High Pressure Fluid Service.

(f ) High Purity Fluid Service: a fluid service that requires alternative methods of fabrication, inspection,

examination, and testing not covered elsewhere in the Code, with the intent to produce a controlled level of cleanness.

The term thus applies to piping systems defined for other purposes as high purity, ultra-high purity, hygienic, or aseptic.

severe cyclic conditions: conditions applying to specific piping components or joints in which SE computed in accordance with para. 319.4.4 exceeds 0.8SA (as defined in para. 302.3.5), and the equivalent number of cycles (N in para. 302.3.5) exceeds 7000; or other conditions that the designer determines will produce an equivalent effect.

For PWHT Requirement

331.1.3 Governing Thickness. When components are joined by welding, the thickness to be used in applying the heat treatment provisions of Table 331.1.1 shall be that of the thicker component measured at the joint, except as follows:

(a) In the case of branch connections, metal (other than weld metal) added as reinforcement, whether an integral part of a branch fitting or attached as a reinforcing pad or saddle, shall not be considered in determining heat treatment requirements. Heat treatment is required, however, when the thickness through the weld in any plane through the branch is greater than twice the minimum material thickness requiring heat treatment, even though the thickness of the components at the joint is less than the minimum thickness. Thickness through the weld for the details shown in Fig. 328.5.4D shall be computed using the following formulas:

(b) In the case of fillet welds at slip-on and socket welding flanges and piping connections DN 50 (NPS 2) and smaller, for seal welding of threaded joints in piping DN 50 and smaller, and for attachment of external non pressure parts such as lugs or other pipe supporting elements in all pipe sizes, heat treatment is required when the thickness through the weld in any plane is more than twice the minimum material thickness requiring heat treatment (even though the thickness of the Components at the joint is less than that minimum thickness) except as follows:

(1) not required for P-No. 1 material, when weld throat thickness is 16 mm (5⁄8 in.) or less, regardless of base metal thickness.

(2) not required for P-No. 3, 4, 5, or 10A materials when weld throat thickness is 13 mm (1⁄2 in.) or less, regardless of base metal thickness, provided that not less than the recommended preheat is applied, and the specified minimum tensile strength of the base metal is less than 490 MPa (71 ksi). (3) not required for ferritic materials when welds are made with filler metal which does not air harden. Austenitic welding materials may be used for welds to ferritic materials when the effects of service conditions, such as differential thermal expansion due to elevated temperature, or corrosion, will not adversely affect the weldment.

a) Annealing: heating to and holding at a suitable temperature and then cooling at a suitable rate for such purposes as: reducing hardness, improving machinability, facilitating cold working, producing a desired microstructure, or obtaining desired mechanical, physical, or other properties.

(b) Normalizing: a process in which a ferrous metal is heated to a suitable temperature above the transformation

range and is subsequently cooled in still air at room temperature.

(c) Preheating: the application of heat to the base material immediately before or during a forming, welding, or cutting process. See para. 330.

(d) Quenching: rapid cooling of a heated metal.

(e) Recommended or required heat treatment: the application of heat to a metal section subsequent to a cutting, forming, or welding operation, as provided in para. 331.

(f) Solution heat treatment: heating an alloy to a suitable temperature, holding at that temperature long enough to allow one or more constituents to enter into solid solution, and then cooling rapidly enough to hold the constituents in solution.

(g) stress-relief: uniform heating of a structure or portion thereof to a sufficient temperature to relieve the major portion of the residual stresses, followed by uniform cooling slowly enough to minimize development.

(h) Tempering: reheating a hardened metal to a temperature below the transformation range to improve toughness.

(i) Transformation range: a temperature range in which a phase change is initiated and completed.

(j) Transformation temperature: a temperature at which a phase change occurs of new residual stresses.

ASME SEC IX REQUIREMENTS

QW-200.1A (a) Welding Procedure Specification

WPS is a written qualified welding procedure prepared to provide direction for making production welds to Code requirements.

QW-200.2 (a) Procedure Qualification Record

A PQR is a record of the welding data used to weld a test coupon. The PQR is a record of variables recorded during the

welding of the test coupons. It also contains the test results of the tested specimens. Recorded variables normally fall

within a small range of the actual variables that will be used in production welding.

.

Welder Performance Qualification Test: The performance qualification tests are intended to determine the ability of welders and welding operators to make sound welds.

A welder or welding operator may be qualified by radiography of a test coupon, radiography of his initial production

welding, or by bend tests taken from a test coupon except as stated in QW-304 and QW-305.

QW-304 Welders

A welder qualified to weld in accordance with one qualified WPS is also qualified to weld in accordance with other

qualified WPSs, using the same welding process, within the limits of the essential variables of QW-350.

QW-401.1 Essential Variable (Procedure). A change in a welding condition which will affect the mechanical properties (other than notch toughness) of the weldment (e.g., change in P-Number, welding process, filler metal, electrode, preheat or postweld heat treatment).

QW-401.2 Essential Variable (Performance). A change in a welding condition which will affect the ability of a welder to deposit sound weld metal (such as a change in welding process, deletion of backing, electrode, F-Number, technique, etc.).

QW-401.3 Supplementary Essential Variable (Procedure).

A change in a welding condition which will affect the notch-toughness properties of a weldment (for example, change in welding process, uphill or down vertical welding, heat input, preheat or PWHT, etc.). Supplementary essential variables are in addition to the essential variables for each welding process.

QW-401.4 Nonessential Variable (Procedure). A change in a welding condition which will not affect the mechanical properties of a weldment (such as joint design, method of back gouging or cleaning, etc.)

  

NOTES: (1) Positions of welding as shown in QW-461.1 and QW-461.2.  F-Flat H – Horizontal V – Vertical O- Overhead

(2) Pipe 27⁄8 in. (73 mm) O.D. and over.(3) See diameter restrictions in QW-452.3, QW-452.4, and QW-452.6.

Legend: _ Change   t Thickness   + Addition    ↑Uphill   − Deletion   ↓Downhill

    

Base metal defects in weld bevel for Pipes and Fittings for Joint Fitup – to be corrected if permissible as per ASME Sec II A, ASME B31.3, SAES-W-011 and other applciable specifications.

328.4.3 Alignment

(b) Circumferential Welds

(1) If component ends are trimmed as shown in Fig. 328.3.2 sketch (a) or (b) to fit backing rings or consumable

inserts, or as shown in Fig. 328.4.3 sketch (a) or (b) to correct internal misalignment, such trimming shall not reduce the finished wall thickness below the required minimum wall thickness, tm.

(2) Component ends may be bored to allow for a completely recessed backing ring, provided the remaining net thickness of the finished ends is not less than tm.

(3) It is permissible to size pipe ends of the same nominal size to improve alignment if wall thickness requirements are maintained.

(4) Where necessary, weld metal may be deposited inside or outside of the component to permit alignment or provide for machining to ensure satisfactory seating of rings or inserts.

(5) When a girth or miter groove weld joins components of unequal wall thickness and one is more than 11⁄2 times the thickness of the other, end preparation and geometry shall be in accordance with acceptable designs for unequal wall thickness in ASME B16.25.

(6) Buttweld fittings manufactured in accordance with ASME B16.9may be trimmed to produce an angular joint offset in their connections to pipe or to other buttweld fittings without being subject to design qualifications in accordance with para. 304.7.2 provided the total

angular offset produced between the two jointed parts does not exceed 3 deg.

328.4.3 Alignment

(a) Circumferential Welds (1) Inside surfaces of components at ends to be joined in girth or miter groove welds shall be aligned

within the dimensional limits in the WPS and the engineering design.

(2) If the external surfaces of the components are not aligned, the weld shall be tapered between them.

SAES-W-011

11.3.5 Buttering or weld build-up on joints

11.3.5.1 Buttering or weld build-up on the prepared surfaces shall not exceed the lesser of ⅓ of the base metal thickness or 10 mm without the approval of CSD. If the buttering or build-up exceeds this, then the following requirements shall apply:

a) The buttering operation shall be witnessed by Saudi Aramco Inspection.

b) The buttering shall be inspected by RT, and PT or MT after completion of the build-up but before final welding of the joint.

18.6 Damage or deformation to the base metal or welds, including dimensional changes, caused by external forces (intentional or accidental) requires special repair and inspection procedures to be submitted to Saudi Aramco Inspection and if necessary forwarded to CSD for review and approval prior to undertaking the repairs.

11.14.5 The back purge for stainless steel and nickel alloys shall reduce the oxygen level below 0.05%. An oxygen analyzer should be used to determine the oxygen content inside the pipe during purging. If more than 20 joints are to be welded at the same time then minimum of 10% of the total joints shall be analyzed.

11.16 Weld encroachment and minimum distance between welds.

The distances shall be measured between the edges of the adjacent cap passes. These restrictions do not apply if one of the welds has been post weld heat treated prior to making the second weld or both welds have been post weld heat treated and inspected.

11.16.1 The minimum distance between parallel butt welds shall be 20 mm or three times the wall thickness of the joint, whichever is greater.

11.16.2 Pressure containing welds (e.g., nozzles and other attachments) shall be separated from other pressure containing welds by no less than 20 mm or three times the joint thickness, whichever is greater. Radiography of the butt welds is required for situations in which the minimum separation is not achieved. For joints other than butt welds, other appropriate inspection methods shall be used, depending on the geometry and material.

11.8 If any grinding reduces the base metal thickness to less than the design minimum, the ground area shall be rewelded and ground flush with the original base metal surface or the component shall be replaced. Rewelding shall be done only with the prior approval of Saudi Aramco Inspection.

Production hardness testing for welds in P-No 1 material in sour or PWHTed service shall also be performed. 10% of the welds shall be sampled. The maximum allowed hardness is 200 BHN.