Hose subjected to external pressure?
Hose subjected to external pressure?
(OP)
Has anyone had experience with hoses operating (at least some of the time) with an external pressure higher than the internal pressure? I have a device that will be operating submerged at up to 100 psi, and I need to plumb fairly low pressure fluid into it (typically 25 - 30 psi above the case pressure) via a flexible connection.





RE: Hose subjected to external pressure?
Suction hoses have large wire helicals to support against collapse, but I have never heard of anything over -30 in hg (one atmosphere).
How about the undersea and oil rig industries, they must have conductors in these types of conditions.
RE: Hose subjected to external pressure?
Thin wall to ID hoses will collapse under external pressure regardless of the material used (this is probably similar a long thin column collapsing - think structural engineering).
Consider a hose with very thick wall to ID ratio.
An example here - second picture
http://www.hyvac.com/Products/Parts/vac_hose.htm
RE: Hose subjected to external pressure?
Will run off now and do some experiments with varying hose wall thicknesses and reinforcements. Since the condition is probably going to be a very rare occurrence, especially if cautions to operators are given to prevent it, I'm thinking of doing only a very nominal 100 to 1000 cycles of maximum expected negative pressure, and see how the hose holds up.
RE: Hose subjected to external pressure?
Or is there anything to stop you running the casing dry but pressurised to ambient? (Accepted that there are often lots of good reasons to not want to do this).
A.
RE: Hose subjected to external pressure?