About Central Boilers Board •Contents Chapter Wise • Contents Regulation WiseIndian Boilers Act 1923
Reg. 189
DISHES END PLATES

Dished ends subject to internal pressure

a) For unstayed ends of steam and water drums, tops of vertical boilers, etc., when dished to partial spherical form the maximum working pressure shall be determined by the following formula : -
 W.P. = 15 x S x (t - 1) Eqn.(24) R

Where
W.P. is the working pressure in lbs. per square inch,

t is the thickness of end plates in 32nds of an inch.

R is the inner radius of curvature of the end in inches, which shall not exceed the external diameter of the shell to which it is attached,

S is the minimum tensile breaking strength of plate in tons per square inch, or whatever is allowed for it.
b) The inside radius of curvature of the flange shall be not less than 4 times the thickness of the end plate, and in no case less that 2-1/2 inches.
c) When the end has a manhole in it (t - 5), shall be substituted for (t - 1) in the formula.
d) The total depth of flange of manhole from the outer surface in inches measured on the minor axis shall be at least equal to -
 (T x W) 1/2 = depth of flange in inches. Eqn.(25)

where
T is the thickness of the plate in inches,, and

W is the minor axis of the hole in inches.

NOTE - The foregoing provisions shall not preclude the use of dished ends in compliance with Regs.275 to 278, where not fitted with an up-take.

 About Central Boiler Board Foreword • List of Amendments Ibr Forms • Home • Search • Help • Contact Us