Blind Flange Design With Multiple Opening

https://cr4.globalspec.com/thread/119626/Bolted-Blind-Flange-Design-As-Per-ASME

There is a <...suggestion...> that this is a duplicate thread (see #1⇑).

One wonders what other suggestions might occur on this particular thread that might differ from those on the original thread, and how any evaluation of those differences might be carried out. Any <...suggestion on this...> (rhetorical question - NNTR)?

Of course, this is a rhetorical question because I have posted this question for learning more about this from the ASME. I have already mentioned the ASME clause used for the design of blind flange in my earlier question and I am pretty sure this is correct. But I want to discuss more and want an opinion from the ASME expert and seniors like you.

"But I want to discuss more"

Then why don't you continue discussing it, in the thread you started just yesterday? What was the point of opening a duplicate thread?

Quite.

Not my specialty, but what you have drawn cause me immediate concern.

Holes N11 and N4 so close together form a local weakening in the flange, as also N1 and N3. You have removed 9" of section from that side of the flange AND whatever the mounting bolts for those nozzles also rob from the parent flange PLUS another two 45mm holes.

Don't like it one bit!!

Also, is it still a "Blind Flange" when it has 24@45mm holes through it??? As I say, not my field, but interested in response.

Thank you very much.

Yes, The blind flange has 24@45mm holes which I have shown in the drawing sketch.

Read this again:⇒ #5

Blind flange with 24 holes is used for to mount the candle element on it.

N1-N4 Nozzles are for Vent, Gas In another two nozzles is for Instruments and N11 is a spare nozzle. No pressure is acting inside the hole.

Design Pressure is 6 Bar (g)

MOC of flange : SA 516 Gr.70

External Design Pressure : Atm

Design Temp. = 80 deg C

Application = Speciality Chemicals

Group = Inorganic Chemicals

ASME VIII is client requirement.

Thank you

To be honest I'm not really sure what is to discuss here. You're using a commonly available material in conditions which don't appear to be very testing...pressure isn't particularly high and temp is fine. You've been asked to design it to ASME VIII which, without going through it to verify, I presume you have done.

Hmmm, what exactly are you look for from us?

I am sure with my calculation but I am just looking for feedback/suggestion from ASME expert from pressure vessel industry regarding whether I am going in the right direction or not.

I'm not 100% sure on this application, I work in oil and gas, but the 24 off holes for the candle element look like they will need to be sealed. Is that a suitable sealing surface?

Also, why is your spare nozzle 3" when N1-N4 are 2"?

Post 11 seems to show a mix of metric and imperial dims. Not a good idea.

Post 11 shows lining of the 2" holes. I don't know what that lining is but is it practicable to get the lining in there?

Again in post 11 it looks like there is a requirement to drill 4-1/2" holes to a depth of 22mm. If I'm reading that right it looks wrong to me.

There looks to be some weight in that too. With a 2 point lift you have a higher chance of trapped fingers etc when manual handling it. If this was designed deliberately to allow you to swing it from horizontal to vertical then fine, if this isn't a requirement a 3 point lift is safer.

Again I don't know the intent of this application but would it be worth having your gas in and vent holes at 180 deg on the same PCD? You want to purge the chamber of air with the gas???

Well there are some of my thoughts, maybe if you continue this discussion others might see some mistakes in my thoughts or be able to contribute?

Wrong procedure. The problem with gathering opinions from disconnected, anonymous strangers on a global Engineering discussion forum is that none of the opinion-makers, nor the forum's operators, are going to be liable should the thing go wrong, either in design, or in testing, or in service.

The correct procedure is to involve a second person at the facility to do a sanity-check on the calculations, and then for the facility to bounce the whole proposal off the insurance company that will be undertaking liability under an insurance policy, for which the vessel will need assessment during design and testing before it is put into service.

The next step is to write a procedure that embraces this philosophy for future reference so that there is no need to reinvent the proverbial wheel.

Nothing has changed since the earlier thread. Nor is it expected to change.

A blind flange is a solid disk used to block off a pipeline or to create a stop. Similar to a regular flange, a blind flange has mounting holes around the perimeter and the gasket sealing rings are machined into the mating surface. The difference is that a blind flange has no opening for fluids to pass through. Instead, it is placed in between two open flanges, which stops the flow through a pipe. Many times this type of blockade is used when adding another line onto an existing pipeline or when a new valve is being added.

Refer below sketch for better understanding.

Never mind all that.

WHAT DO THE VESSEL'S POTENTIAL INSURERS HAVE TO SAY ABOUT IT?

<...want to discuss...> It's gone awfully quiet...