Subsea Pressure Vessel Design

1. internal and external pressure.

2. coating to prevent corrossion.

just my 2 cents...

You will especially need to compare the internal pressure of the vessel with the external pressure, most notably taking into account any loss of internal pressure. In particular, this may entail stiffening ribs to support the vessel. Can you provide some pressure data?

Will it be pressurised prior to being submerged? If so then it will need to be strong enough to withstand internal pressure at atmospheric pressure/sea level.

If it will only be pressurised when submerged then it will need to withstand maximum external pressure (at depth).

If it will vary depth/pressure then it will need to be strong enough to withstand both pressure max as a variable.

Else is it feasible to use a flexible bladder? If filling a solid vessel at depth then any gas contained will need to be vented but there will be no source to recover from. If you don't vent then your pump will need to either pressurise enough to compress the gas or if you use a flexible bladder then overcome the external pressure.

Ultimately depends on depth you're planning on working at.

Dear Praphulla,

Your biggest challenge is to design the vessel against hydrostatic collapse. If the vessel is empty and on the seabed with maximum hydrostatic head, this is normally your governing condition. Also make allowance if there is any vacuum in the vessel caused by vacuum drying of the attached pipework. The codes you need to use are ASME VIII for the vessel and API 1111 for the pipe

I wish you success with your (interesting) challenge

Stewie

in which type pressure vessel you design.

is it thin cylinder or thick cylinder pressure vessel?

http://en.wikipedia.org/wiki/Submarine#Overview