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 Under water crush depth. Post Reply Forum
 Posted by: Mylo42 ® 08/23/2005, 10:50:12 Author Profile eMail author Edit I am building a submersible in which the pressure hull is made of 28" steel pipe with a wall thickness of 1/2" (140lb/ft weight of pipe). Assuming that the flat end caps are as integral as the pipe due to reinforcement. How can I calculate the crush depth ? This # would obviously be halved to obtain a safe operating max. depth.Thanks for the help.Mylo42

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 Re: Under water crush depth. Re: Under water crush depth. -- Mylo42 Post Reply Top of thread Forum
 Posted by: swearingen ® 08/23/2005, 18:34:18 Author Profile eMail author Edit Using Roark's and plate theory, I get that the end plate should begin to yield at about 85' of depth (37psi). I thought that maybe it isn't that deep until you calculate the total load on the plate - 22,700lb - over 11 tons! It'll hold up a little deeper until it passes the hump on the stress-strain curve, then it's a goner. This does not take into account the increase in pressure on the inside from the decreasing volume, so that'll add a few feet of depth. To be on the safe side, I wouldn't take it down deeper than 40' or so.If you dome the ends you can get much deeper...