Circumferential and End Seams of Water Tube Boilers
The suitability of circumferential seams including the seams
joining ends to shells shall be verified by the following formula
|K x J x (t-2)
||is equal to or
greater than W.P.
|D x C
K = 150 for 26/30 tons tensile plates.
K = 157 for 28/32 tons tensile plates.
Due to higher stresses, see regulations
271 and 340.
WP = The working pressure in lbs per sq. in.
D = The diameter of shell in inches, measured inside the
outer ring of plates.
J = Circumferential Joint efficiency calculated by Eqn.2
C = 8.24 where the seams are made with lap joints and are
= 8.44 where the seams are made with lap joints and are
= 9.60 where the seams are made with lap joints and are
t = thickness of plate in 32nd of an inch.