pressure embosed jacket on atm. tank.

[401laurent]

Hi,
I have to design a small cylindric & atmospheric tank (500gal.),with pressure jacket for thermal transfert,which is constituted of helical U channel all around the tank shell.
my questions are:

1- to design the jacket ,can I consider that this is embossed jacket and then I can apply Appendix 17 of ASME Sect VIII div.1,UW-19(c)and UG-47
2- am I obliged to do a proof test to establish the MAWP
for pressure jacket ,and if Yes how to do it ?
(I did it for a dimple jacket per UG-101(m), five pitch in 2 direction and min of 24 po on the test assembly) but in this case I dont Know what can be the pitch of my helical U jacket.

Please if you need more details let me know,
all idea or suggestions are appreciated.
Tank you.

 

[vesselguy]

Laurent,
Why design the jacket when you can purchase them from a manufacturer? There are a few company that make these. Do a Google search for "Tank heater" you'll have a few hits. Don't know your application but there are many tank heater design available.

Anyway, if you're designing your coil to Sect 8 code and it is > 15 psig, you'll have to hydrotest it. If you can calculate the design then you can calculate the MAWP. There isn't enough info given to answer your question.

 

[401laurent]

Vesselguy,
Thank you for your reply,
1-we prefer design and fabricate our jacket, because its more expensive to purchase it.
2- You know it not easy to calculate the MAWP, that why the code recommend to do the proof test using UG-101, to determine the MAWP.

habitually here in Canada we register the jacket after proof test as part (accessory). and then when we have the similar design on other tank or vessel, we can use the similar kacket design ( same or stronger matls and thk )without any other test.

Now i have some confusion on the test mock-up.

I hope that now it's more clear.
Than you