More A Starting materials shall consist of plate, sheet, forgings, forging quality bar, and seamless or fusion-welded tubular products with filler metal added. Materials shall be heat treated by normalizing, quenching, and tempering or stress relieving. Specimens shall conform to required values of chemical composition and mechanical properties, namely: yield strength, tensile strength, elongation, notch toughness, and hardness.

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Size The nominal size of the pipe fitting is shown in the nominal outside diameter of the pipe to which it is connected. Design Proof Test When the manufacturer selects a proof test to ensure the quality of the fitting design, the test shall be performed in accordance with the provisions of this standard practice.

It shall be based on the calculated burst pressure of the fitting and its connecting piping as defined in Section 4. Factory-made segmented elbows need proof test on geometrically similar degree elbows without the need for separate testing.

Test Assembly Requirements Fittings with the same basic design configuration and manufacturing method shall be selected for testing from production. And it shall be determined for materials, grades and batches, including heat treatment.

They should be checked for compliance with the dimensional requirements of this standard. Straight Seamless or Welded Pipe The calculated bursting strength of a straight seamless or welded pipe is at least as great as the proof test pressure calculated in Section 4.

And it shall be welded to each end of the fitting to be tested. The nominal wall of the pipe section may be larger than the thickness indicated by the assembly marking. The greater thickness shall not exceed 1. Any internal misalignment greater than 0. For greater than NPS 14, the minimum length of pipe sections for closures shall be one-half pipe, and it shall be one pipe fpr NPS 14 and smaller.

Test Fluid The test fluid should be water or other liquid. Hydrostatic pressure should be applied to the assembly. It is recommended to perform at least three proof tests for each fittings, join size or configuration. Meanwhile it shall be taken to rupture or held at or above computed minimum proof pressure for a period of at least 3 minutes. Materials The steel should be fully "killed" and manufactured using accepted smelting methods to provide intended heat treatment response and notch toughness.

Steel shall be suitable for on-site welding of other fittings, flanges and pipes manufactured in accordance with the applicable specifications listed in the ASME B31 specification. The pipe material shall be steel ingots, billets, sheet steel, forged quality bars, steel plates, seamless welded or welded pipes with additional filler metal.

The steel used shall be of suitable welding quality carbon steel or high strength, low alloy steel of suitable welding quality. Heat Treatment All fittings should be delivered under heat treatment.

Hot formed fittings should be cooled below the critical temperature prior to heat treatment. The pipe fittings shall be subjected to one or more heat treatments as specified below.

Stress Relief Unless otherwise requested by the purchaser and the manufacture, stress relief should be limied to guide bar welds. Normalizing The pipe fittings should be reheated evenly above the transition temperature austenite zone , at which temperature the hold time should be long enough to reach uniform temperature, and then cooled in air.

Normalizing and tempering The pipe fittings shall be normalized in accordance with the normalizing regulations. Quenching and tempering The fitting should be uniformly reheated above the transition range, maintained at a temperature sufficiently to achieve a uniform temperature throughout the material, and immediately immersed in a suitable liquid medium. Then reheat and temper according to the rules of normalizing and tempering.

The quenching facility should be of sufficient size to ensure that the pipe is evenly cooled. If the purchaser specifies, manufacturing must not be carried out until the purchaser accepts the MPS.

It should indicate the following items, if applicable: a. For starting materials: 1. Product form seamless or welded and size, 2. Welding NDE results if the fittings manufacturer does not complete. For fitting manufacture 2.

Welding procedure specification and approval record, if applicable 3. Heat treatment procedure including thermal cycles 4. Machining requirements 5. Inspection, dimensions and test requirements 6. Proof test results if requested 7. Traceability c. Additional requirements such as end preparation, coating and marking. The fittings can be fabricated by forging, hammering, pressing, drawing, stamping, extruding, welding, or some combination of these operations.

The molding steps used should not cause harmful defects in the pipe fittings. Tees, elbows and other fittings are made using circumferential or intersection welds eg, miter welds. They are considered to be pipe manufacturing, and are outside the scope of this standard practice.

All outlets for NPS 2 and larger shall be of integral profile, and the outlet end shall be matched to the specified connection pipe or fitting. Welding Manufacturing Machine Welding Machine welding should be carried out using an electrical process, and submerged arc welding is better.

Butt Weld All butt welds should be completely penetrated. Submerged arc welders should be welded at least once from the inside unless the accessibility makes it impossible. Then, if the root weld can be visually inspected, a manual or machine root weld bead can be adopted. Do not use the backing ring. Repair, Chipped and Ground The weld shall be repaired, chipped or ground in a manner that does not create gouge, grooves, or reduce the thickness of the raw material not exceeding 6.

Fillet Weld Fillet welds shall have full weld throats a. If not otherwise specified, the two weld legs shall be approximately equal length. If a welded bracket is used, it should be removed prior to heat treatment and the weld spot need to be repaired and ground flush, and smoothed. However, if brackets are required for heat treatment, they should be cut off ,and the surface should be ground flush nd smoothed after heat treatment.

Welding is not allowed after heat treatment. Workmanship and Finish Pipe fittings should not have harmful defects, and the surface should be smooth and flat. However, when depth exceeds 6. Surface defect treatment If harmful defect, such as notches, scratches, scabs, seams, laps, tears, or slivers, not deeper than 6. The defect can be repaired by welding process. When the depth of the defect exceeds However, it must be completely removed and welded by a qualified welder.


ASTM A860 Mss Sp 75 Wphy 60 Pipe Fitting Reducer



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