(a) Major repairs such as fusion welded or riveted patches to shells, fire boxes and end plates of boiler and extensive building up of wasted parts of boilers permitted under these regulations, the renewal of furnaces and end plates, parts of shell, fire boxes girders & steam pipes etc., shall only be entrusted to a repairer who can satisfy the Chief Inspector regarding the quality of welding and other repair done by his organization and all other minor repairs which may be determined to be minor by the Chief Inspector at his discretion may be entrusted to any repairers.
(b) Welding- The repairer shall satisfy the Chief Inspector.
(i) That the electric arc or oxy-acetylene welding sets and an other tools and plant in his possession for carrying out repairs are suitable for the work undertaken.
(ii) That the quality of material used conforms to the specifications that are prescribed.
(iii) That the supervisory and operational staff employed by him possesses the necessary training and experience for the work under taken.
(iv) That all welders employed by him possess certificates issued as required under Chapter XIII of these Regulations.
(v) Standard of work should be of high order and comply with all the requirements and test that may be prescribed by the Chief Inspector.
(c) Riveting and Other Repairs- The Repairer shall satisfy the Chief Inspector:
(i) That he possesses the necessary equipment and tools and engages trained and experienced workmen and staff for the work under taken.
(ii) Standard of work should be of a high order and comply with all the requirements and test that may be prescribed by the Chief Inspector, and all material used shall be of boiler quality.
(d) The repairs should be supervised, so far as his other duties permit by the Inspector when the fire boxes and smoke tubes of locomotive tube boilers are withdrawn, the opportunity should be taken to inspect the internal parts which are otherwise inaccessible to close inspection.
(e) Repairs to boiler shells shall be affected either by patching or by removing a stripe of worn or damaged plate and inserting the new strip with covering straps over the longitudinal butt ends, the strength of the riveted joints to be not less than that of the longitudinal joints of the shell.
(f) Patches for fire exposed plates shall be fitted metal to metal without joint of any description. The affected part shall be cut out, leaving the corners of the hole rounded. Patches shall be secured, wherever possible, properly spaced rivets with a width of plate at least equal to the diameter or rivet between the edge of the rivet hole and the edge of the plate. Where riveting is impracticable, the plate shall be secured by well fitting countersunk headed screw pins.
(g) The thickness of a patch plate shall not be less than the original thickness of the plate which it is used to patch.
(h) Bulged or distorted furnaces of circular section may, if the bulge of distortion is not too great, be pressed back to shape.
(i) Circular furnaces horizontal boilers that have become distorted may be suitably reinforced.
(j) Anti-collapse rings shall be of substantial section either of single or double angles bolted back to back with screw stays not less than 7/8th inch in diameter and about 7 inches in pitch passed thought flat of angle and screwed into the furnace, the ends being either rounded or riveted over on the fire side and fitted with nuts at the other. The stay bolts shall be fitted with ferrules not less than 1 inch in depth between furnace and angle ring.
(k) Welding shall not be accepted for the repair of any part of a boiler for which welding is forbidden for a new boiler under these Regulations. Boiler shells shall not be repaired by welding beyond the filling up of a small isolated corroded or pitted part or the making up of wasted edges of openings.
(l) Cracks or grooving in dished or flat end plate of cylindrical shells or in the bends of furnace flanges in a circumferential direction may be weed out and welded.
(m) Wasted parts of circular furnaces and fire boxes and fire exposed flat plates as in rectangular fire boxes and combustion chambers may be cut out and be replaced by new pieces welded in or they may be built up by welding. Longitudinal cracks in circular furnaces and fire-boxes and cracks in rectangular fire-boxes and combustion chambers may be welded.
(n) No Stay shall be welded.
(o) For the purposes of these Regulations renewed part shall be deemed to be parts of a new boiler intended for use at the pressure at which the boiler under renewal is used.
(p) Butt Welding of Smoke Tubes- Smoke tubes may be butt welded either by fusion welding, flush welding or oxy-acetylene welding, and these should be tested hydraulically at the discretion of the Chief Inspector.
Last Updated Date :- 24-07-2019
Page last updated on: 18-10-2021