raymondxuwen
Mechanical
- Mar 30, 2015
- 2
Could someone help me with my Dimple Jacketed Vertical Full Vacuum Tank Code Design please:
Material: T304 SS, Dia. of 72" and straight shell of 78", D & F heads at the ends, tank internal design pressure : full vacuum (-14.7 psi) at 250F degree, dimple jacket: 45 psi, 250F degree hot water, dimple jacket divided into three zones, two for side wall with a height of approxi. 36" full circuferenced coverd respectively, and one for bottom full covered (to reduce volume of each zone for avoiding Pressure Vessel Regulation)
I used the TSSA registed dimple sheet 14 Ga, (as per UG-101 & UG-47, maximium dimple design pressure: 150 psi at 300F degree with a minimum backing plate(tank shell) thickness of 10 Ga (0.1406").
As per UG-28, formula: Pa = 4B/3(Do/t), If I assume design thickness of the tank shell is 1/4", should I use t = 1/4" or t = 1/4" - 0.1406 = 0.1094" to verify Pa for tank inner pressure? (In other words, should I conside the design pressure as 14.7 + 45 = 59.7 psi for a external pressure vessel or just use 14.7 psi to perform calculation since this is braced and stayed members in accordance with paragraph UG-47.
Material: T304 SS, Dia. of 72" and straight shell of 78", D & F heads at the ends, tank internal design pressure : full vacuum (-14.7 psi) at 250F degree, dimple jacket: 45 psi, 250F degree hot water, dimple jacket divided into three zones, two for side wall with a height of approxi. 36" full circuferenced coverd respectively, and one for bottom full covered (to reduce volume of each zone for avoiding Pressure Vessel Regulation)
I used the TSSA registed dimple sheet 14 Ga, (as per UG-101 & UG-47, maximium dimple design pressure: 150 psi at 300F degree with a minimum backing plate(tank shell) thickness of 10 Ga (0.1406").
As per UG-28, formula: Pa = 4B/3(Do/t), If I assume design thickness of the tank shell is 1/4", should I use t = 1/4" or t = 1/4" - 0.1406 = 0.1094" to verify Pa for tank inner pressure? (In other words, should I conside the design pressure as 14.7 + 45 = 59.7 psi for a external pressure vessel or just use 14.7 psi to perform calculation since this is braced and stayed members in accordance with paragraph UG-47.
