Date Rev No.9/7/2013 0 DESIGN OF LIMPET COIL AS PER APPENDIX -EE The maximum permissible pressure " P' " in half-pipe jackets shall be determined from the following formula: P' = F/K P1 P' = Half pipe jacket Internal pressure = The Maximum permissible pressure in half pipe Jacket Since P' is greater than half pipe jacket pressure (P1) Hence shell thickness is safe for external pressure F K = 1.5S -S' = ( F SHALL NOT EXCEED 1.5 X S) Factor obtained from Fig. EE-2 (Considering 3 inch pipe) (For respective shell Inner diameter and shell thickness value of Parameter "K") S = Maximum Allowable Tensile stress at design temperature (220 °C) of shell or head material , psi (Refer Tank calculation for allowable stress) = Actual longitudinal tensile stress in shell or head due to internal pressure and other axial forces, psi. When axial forces are negligible , S' shall be taken as PR / 2t. When the combination of axial forces & pressure stress (PR/2t) is such that S' would be a negative number, then S' shall be taken as zero. S' S' = PR/2t where P = Internal design pressure R = Inside shell or head radius D = 2R (Diameter of shell ) t C.A. = Thickness of Shell (In corroded condition) = Corrosion Allowance for tank shell is t (asbuilt)= Actual Thickness of shell Thickness of Half Pipe Jacket psi( P1 shall not exceed P') Considering pitch of coil 135 mm for 3 inch size . psi Design pressure in jacket. the weight of coil would be around .6P1 Considered SCH 5 ( 2 mm thick ) Pipe for 3 inch pipe.85S1-0.T = P1 X r 0. T r S1 P1 = Minimum thickness of half pipe jacket in = Inside radius of jecket defined in fig EE-3 inch = = Allowable tensile stress of jacket material at design temperature . 88 Mpa wable stress) INTERPOLATION = = = 0 0 0 Psi Kg/cm2 Psi m mm inch m inch mm inch mm mm x1 x2 x3 y2 = 0 10 27.77 Psi = 20142.000 8.000 .3 280.5 = 1500 = 59.06 = 3 = 118.000 0.84 Psi 138.236 2.26 107.Prepared By Checked By Approved PENDIX -EE Psi = = = 15 213.36 kg/cm2 Psi Psi = = 30214.09 30 = 1.110236 = = = = 6. 245 kg/cm2 = 17095.75 inch 1202.= = 0.658 inch mm 1.9239 psi 213.3 psi = 1400 kg (approx) .026 0. INTERPOLATION y1 y2 y3 0 0 . Date Rev No. When axial forces are negligible . then S' shall be taken as zero. S' shall be taken as PR / 2t.A. psi. When the combination of axial forces & pressure stress (PR/2t) is such that S' would be a negative number. S' S' = PR/2t where P = Internal design pressure R = Inside shell or head radius D = 2R (Diameter of shell ) t C. EE-2 (Considering 3 inch pipe) (For respective shell Inner diameter and shell thickness value of Parameter "K") S = Maximum Allowable Tensile stress at design temperature (220 °C) of shell or head material . 9/7/2013 0 DESIGN OF LIMPET COIL AS PER APPENDIX -EE The maximum permissible pressure " P' " in half-pipe jackets shall be determined from the following formula: P' = F/K P1 P' = Half pipe jacket Internal pressure = The Maximum permissible pressure in half pipe Jacket Since P' is greater than half pipe jacket pressure (P1) Hence shell thickness is safe for external pressure F K = 1.5 X S) Factor obtained from Fig.5S -S' = ( F SHALL NOT EXCEED 1. = Thickness of Shell (In corroded condition) = Corrosion Allowance for tank shell is t (asbuilt)= Actual Thickness of shell Thickness of Half Pipe Jacket . psi (Refer Tank calculation for allowable stress) = Actual longitudinal tensile stress in shell or head due to internal pressure and other axial forces. 6P1 Considered SCH 5 ( 2 mm thick ) Pipe for 3 inch pipe. psi Design pressure in jacket.85S1-0. T r S1 P1 = Minimum thickness of half pipe jacket in = Inside radius of jecket defined in fig EE-3 inch = = Allowable tensile stress of jacket material at design temperature .T = P1 X r 0. the weight of coil would be around . psi( P1 shall not exceed P') Considering pitch of coil 135 mm for 3 inch size . 26 160 Psi = 20142.88 Mpa wable stress) INTERPOLATION = = = 0 0 0 Psi Kg/cm2 Psi m mm inch m inch mm inch mm mm x1 x2 x3 y2 = 0 10 27.000 0.84 kg/cm2 Psi Psi = = 30214.157 2.5 = 1500 = 59.3 188.06 = 3 = 118.09 30 = 1.84 Psi 138.Prepared By Checked By Approved PENDIX -EE Psi = = = 15 213.000 6.110236 = = = = 4.000 . 3 psi = 1400 kg (approx) .658 inch mm 1.= = 0.75 inch 1202.245 kg/cm2 = 17095.9239 psi 213.026 0. INTERPOLATION y1 y2 y3 0 0 .