Message from
Chairman of Central Boilers Board


About Central Boilers
Board


History of Indian Boiler Regulations

Foreword

Contents Chapter
Wise


Contents Regulation
Wise


List of Amendments

Indian Boilers
Act 1923


Ibr Forms

Home

Search

Help

Contact Us

 

Reg. 578, Reg. 579 A, Reg. 579 B

Manhole openings in flat plates

 

Where manholes are located in flat plates, the opening shall be suitably compensated.

Compensation shall be obtained by flanging the edge of the opening, or by providing a fabricating ring (see Figs. XII/52, XII/53, XII/54, XII/55, and  XII/56 ).

The manhole in the lower portion of the flat front end plates shall be fitted with a flanged strengthening ring, the thickness of the flat portion of which shall be not less (1.5T +1/8 inch)

Where T=the thickness of the end plate in inches, and in boilers of 7 feet and 6 inches diameter and over the manhole frame shall be fitted with a peak to reinforce the portion of the end plate between and below the furnaces and this peak shall be securely welded there to.

In all cases the depth of the flanging or ring shall not be less than that determined by Equation XII/6.

NOTE:-Where the manhole is located in or between tube nests in Multi-tubular boilers or below the furnaces of other Boilers the stay tubes in the boundary rows, or the gusset stays, as applicable, shall be arranged as closely as practicable to the manhole.



Reg. 579 

Plain tubes

(a) Attachment

Plain tubes may be welded at both ends, welded at the inlet end and expanded at the outlet end, or expanded at both ends.

Where the tubes are expanded only, the process shall be carried out with expanders having parallel rollers, and the expanded portion of the tube shall be parallel through the full thickness of the tube plate. In addition to expanding tubes may be bell-mouthed or beaded at the inlet end.

Where the tube is welded to the tube plate, the tube should be lightly expanded to grip the tube hole before welding.




(b) The thickness of tubes under external pressure shall be calculated as under:-

t = WP' .D + C Equation XII/14
1.6f

Where,

t = minimum thickness of tube in mm.
WP' =External working pressure in kg/cm²(g)
D = Outside tube diameter in millimetres
C = Corrosion allowance to be taken as 0.75 millimetre but for
Stainless steel C=0.
Higher value may be adopted if desired by user;
F = allowable stress as per regulation 338.

 
Back   Top
Message from Chairman of Central Boilers Board About Central Boiler Board History of Indian Boiler Regulations Foreword Contents Chapter Wise Contents Regulation Wise List of Amendments
Indian Boilers Act 1923 Ibr Forms Home Search Help Contact Us