Alternative to 600 lb flange for pressure vessel 2

[circlespot]

I am designing a pressure vessel using a 16 or 18 inch piece of pipe. I need to be able to remove the end of the pipe in order to gain access to the full pipe ID. The vessel will contain water at 1200 psi and 20 C. A 600 lb blind flange would work but is a huge, expensive piece of metal. Are there any other options for such an application? Is there a design standard for using a cut groove and lock rings on the ID of the pipe?

 

[TomBarsh]

How does the thickness of the standard class 600 blind compare to a bolted cover designed per UG-34? You could possibly design a ring flange with bolted cover that would be more economical than the B16.5 flange with blind.

How about using an "off the shelf" head or pipe cap with a standard B16.5 flange?

 

[unclesyd]

Here two types that you might look at. There are a couple of other types designed under API rules.
I don't have access to my favorites list at the present time so Ill have to do a little scouting.

http://www.oceaneering.com/Grayloc.asp?id=759

Good comparison of size

http://www.ltsusa.com/Techlok-Grayloc Type.htm

 

[circlespot]

Thanks unclesyd. This is exactly the type of alternative I was looking for. I was looking at Victaulic type couplings but they only go up to 350 psi in the 18 inch size.