Hi folks, I am looking for a manway about 700 mm dia for a vessel that has a max allowable working pressure of 1800 psi? Who makes such a manway? About how much would they cost? Vendors welcome to contact me offline if allowable in the forum.

Where you are working, do you have a company or companies who do work on your pressure vessels if they need alternations or repairs? That is likely who I would start with as they will be familiar with your site and work practices. Barring that, get the name of a reputable company who does this work and talk to them about a budgetary estimate, they'll need:

Location of the manway on the vessel, diameter of the vessel and how access to that area will be provided (I'm assuming this will be done in the field)
Design pressure and temperature (class 900, class 1500 flanges? I'm assuming you are looking at a conventional flanged manway)
Metallurgy
Testing requirements
Inspection requirements

TD2k, Thanks for your post. We are designing a HP steam drum. The temp is 625 deg F. approximatly 66-72" dia. The steam drum has a full semispherical head on each end and the manway would be at one end of the drum centered on the head. (It looks like a giant hot dog.) This will be shop installed as it is new construction. This is not a conventional manway. This is specified by the customer as what they want. It was a must have not a wish list. This would be an exterior opening door with some sort of davit.
As to the questions of needing repairs done in the field yes we need vendors but that would be on other issues with existing units. We have many, many units aging in the field.

I can't emphasize enough that the suggestion given by TD2K about getting help as fast as you can. Your requirements present some very specialized design and associated fabrication problems.

In my opinion this project needs to given to a firm that specializes in a POWER BOILERS.

Do not try this without help.

Unclesyd,
Thanks for your comment. We are an engineering firm that can do exactly that. Design the manway. We have one of the oldest asme stamps in the world. We design the drums, the piping, the pressure parts bundles. etc. We are looking to get what we designed, manufactured. The design has not been finalized but with the info we have, we think we should be able to get a quote. The question is from whom? We have checked with Lenape, and others. No numbers have been forth coming. No one stated that they would even entertain this.

Sorry about my comments concern you ability to design such a manway. The question just looked strange as presented. Having seen some very big problems with such equipment I get a little nervous.

We have worked with the following on several occasions, though not in the size range you require. I would try to get pass the front desk to get the straight scoop.

http://www.babcockpower.com/

http://www.fvc.cc/power.htm

http://www.dlflange.com/technical/manufacturing-ca...

http://www.forgedcomponents.com/