Thief Hatch Installation

[Chanster]

Sorry for asking this silly question, but can somebody please tell me where I can find flange dimensional data for an API flange that has a bolt pattern API (16) 11/16 holes on a 10-3/8" circle? I tried looking at API 6A but I get the funny feeling I'm looking at the wrong place.

Thank you for your help.

 

[Bonswa]

API-650 sends you to ASME B16.5 for all flange specifications.

Check out ASME B16.5. Flange dimensions start on page 64. You'll find all the information you can possibly need there.

Hope this helps.

 

[IFRs]

Try this site.

http://www.rjsales.com/products/ansi_asme_flanges/b165/150.html

But - I don't see any flanges with 16 holes on a 10 3/8" circle - that would be one every 2" !!!

 

[jte]

Chanster-

Is this on a relatively small tank, and are you sure you have 11/16” holes and not 9/16”? Besides that discrepancy, your dimensions on bolt circle and number of bolts are in agreement with the Thief Hatch as called out in API 12F Figure 1 and API 12D Figure 3.

The references to B16.5 are for materials. Flange dimensions can vary, as most tanks don’t need flanges capable of 285 psi pressure ratings.

jt

 

[Chanster]

Thank you guys/gals for all your posts.

I'm looking for a flange that would mate up to an Enardo Thief Hatch model 330. I'm looking at their datasheet and it specifies a bolt pattern of 10-3/8" Circle API. I've tried searching for other brand name thief hatch sizes but it appears that this bolt pattern is pretty standard.

I've tried to match this bolt pattern size with B16.5 flanges but could not find a match.

Have you guys installed one of these thief hatches before and how did you do it?

Thank you.

 

[IFRs]

They are 1/2" bolts, likely to be 9/16" holes, do not match an ANSI 8" flange but will match the hole patterns jte mentioned above. You will need a non-ANSI flange or an adapter, or bolt directly to the tank roof plate.

 

[JStephen]

I believe API-12F has standard dimensions for a thief-hatch bolt pattern like this. I assume the hatch bolts directly to the deck plate of the tank, not to a nozzle.