Question

A triple riveted butt joint with equal double cover plates (zig-zag riveting) is used for the longitudinal joint of a Lancashire boiler of 2.5 m internal diameter. The working steam pressure is 1.12 N/mm2 and the efficiency of the joint is 85 per cent. Calculate the plate thickness for mild steel of 460 MPa ultimate tensile strength. Assume ratio of tensile to shear stresses as 7/6 and factor of safety 4. The resistance of the rivets in double shear is to be taken as 1.875 times that of single shear. Design a suitable circumferential joint also.

Answer 1

Giuan A toiple iuetet bott joint Di .5 m CIntenaf dio -12 NmmSt teom Preaswe P Oo85 u6oMPa Coimato Tensile Stoy Sot fos= T Jind plate Hickmeg)(1oupibudnaf joint) P,Di Pexmigsible Tensile Stres 460 5MPa Sot Fos Gt 2 x 2.5 0.O1432 m (2 x 115 X 0.85 14.32 m m Auy

pape) Dayignhy a auilable cemleronin jot 4) Diameteu ap ut 22.7 61432 PtTaing Resishenc P4 = (P-4) p pitc (p-29-1 )fuz) av.32) I15 1 PtP- X Shioniny esislanu Ps Ps 7/ ( 5)- MPa (1.875 )<,3.53) 3 G 6 X て= E24392.78 N

Marimum piteh (Þ) TFrom data) (2,62 p(262x14132) X pnors byenuntng 2 (14.32) x115 224 392.1 X トー227 - P 159mt pmex 159m Accupld valup Dislanu blu yous Cigag pde(0.33 pto.67d

herha pl-(33 v153) + (о.67 Y22.9) 61.679 м kargin (m) 1.50 34.05 - (15)х 82.7 Gе в) ох и В- Pse 224392. (prdrea) -(159 х 1432 X11 224392.7 0.8569 26184/.2 A 8.6990