N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 14-3.10

Current through Register Vol. 46, No. 45, November 2, 2024

Section 14-3.10 - Seal welding

(a) Seal welding of tubes. Tubes may be seal welded provided the ends of the tube have sufficient wall thickness to prevent burnthrough and the requirements of the appropriate sections of the ASME Code are satisfied. Seal welding of tubes shall be done as specified in Figure 14-3.10(1) or by other equivalent methods.

(b) Seal welding of riveted joints. Edges of butt straps or of plate laps and nozzles or connections attached by riveting may be restored to original dimensions by welding. Seal welding may not be used except with the special approval of the authorized inspector, and in no case where cracks are present in riveted areas. Seal welding shall be done as specified in Figure 14-3.10(2) or by other equivalent methods.

(1) Caulking edges of riveted joints, except longitudinal seams of unstayed cylindrical shells or drums subjected to internal pressure, may be seal welded provided the seam is first mechanically caulked and made tight under hydrostatic pressure. Seal welding shall not be considered a strength weld after hydrostatic test.

(2)

(i) Leakage at riveted joints or tube ends must be carefully investigated to determine the cause before welding is permitted.

(ii) Prior to seal welding riveted joints, the area should be examined by an appropriate method of nondestructive examination to assure that there are no cracks radiating from the rivet holes. If necessary, the rivets should be removed to assure complete examination of the area. Seal welding should not be performed if cracks are present in riveted areas.

(3) On tubes, seal welding may be applied on either the outside or the inside. On a riveted joint, seal welding shall be applied on only one side.

(4) Care shall be exercised so that the heat from seal welding will not distort the plates or loosen the rivets.

(5) On dished heads, seal welding shall not be applied to the flange closer than one-half inch to the point of tangency of the knuckle of the flange.

FIGURE 14-3.9(1)--WELD BUILD-UP OF WASTED AREAS

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Wasted areas in stayed and unstayed surfaces may be built up by welding provided that in the judgment of the authorized inspector the strength of the structure will not be impaired. Where extensive weld build-up is employed, the authorized inspector may require an appropriate method of nondestructive examination for the complete surface of the repair.

FIGURE 14-3.9(2)

REPAIRS FOR ACCESS OPENINGS

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A badly wasted manhole flange may be removed and replaced with a ring-type frame as shown above. The requirements of 14-3.16(a) of flush patches shall be met. A full penetration weld shall be required. The weld may either be double welded or welded from one side with or without a backing ring.

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A badly wasted area around a handhole opening shall be repaired by adding a ring as shown above on the inside of the object.

FIGURE 14-3.10(1)

SEAL WELDING OF TUBES

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Tubes may be seal welded provided the ends of the tubes have sufficient wall thickness to prevent burn through. Seal welding shall be applied with a maximum of three light layers in lieu of one or two heavy layers.

In watertube boilers, tubes may be seal welded on the inside or outside of the tubesheet.

FIGURE 14-3.10(2)

SEAL WELDING OF RIVETED JOINTS

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TYPICAL RIVET JOINT SHOWING SEAL WELD

Seal welding of rivited joints requires the approval of the department. Seal welding may not be considered a strength weld. Seal welding shall be applied in one light layer if practicable, but not more than two layers shall be used.

Prior to welding, the area shall be examined by an appropriate method of nondestructive examination to assure that there are not cracks radiating from the rivet holes. If necessary, the rivets shall be removed to assure complete examination of the area. Seal welding may not be performed if cracks are present in riveted area.

N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 14-3.10