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Thanks SnTMan, think we will pursue this, possibly with dowels or keys to take the shear.

Thanks for your suggestions all. In case it helps, to clarify: There is metal-to-metal contact between the tubesheet, channel and shell. The seal is not a gasket in the traditional sense. We have experience with a similar design which has been in-service for a long time so at least there is...

We are in the process of designing a large heat exchanger. It has two fixed tubesheets, for example TEMA type AEL. The tubesheets are "loose" and sandwiched between girth flanges on the shell and channel, similar to the image below. The nozzle loads on the channel are considerable and the...

Dear all, I'm after some insight as to what is considered "normal" in your organisations for showing valve bridgewall markings on piping schematics/P&IDs. Is this information always shown? Sometimes shown? Never shown? Also, what symbols are used? Arrows? The cranked bridgewall marking...

Thanks for your opinions all. Confirms my initial thoughts.

I have a supplier who is proposing to make the nozzles on a pressure vessel from thick plate, eg by boring the plate into a pipe shape. I can't find anything to specifically prohibit this in the code, but I don't think it's right because of the possibility of defects and segregation down the...

A quick search for "visual" in ASME III generates precious few hits - basically the code seems fairly silent on the matter. On the other hand, I expect visual examination to be used liberally, especially for welds. Am I missing something?

Thanks @XL83NL. I've read that post and a couple of similar ones but it's not really giving me the clarity I was looking for. I'm really struggling to decide really if there are any parts, "main pressure-bearing" or "other than main-pressure bearing" where there is no need to get a 3.1 cert. As...

If designing a vessel or piping under the Pressure Equipment Directive (PED) using EN13445 or EN13480, requirements for material certification (3.1, 3.2, 2.1 or 2.2) are given in EN764-5. In EN764-5 is a flow chart which defines the requirements for "main pressure-bearing parts" and...

Dear all, A couple of simple questions which I'd welcome your opinion on... I have a process vessel which is partially filled with a single component saturated liquid. Above the saturated liquid is vapour. Occasionally, due to an upset, the pressure in the vapour space is rapidly decreased. The...

Hi, I am trying to write a macro to determine if an entity (face, vertex, surface etc.) which a user has selected is part of a solid body (ie an item which is a member of the solid bodies folder at the top of the feature tree) or if it is part of a surface (ie an item which is a member of the...

Thanks for your answer, however I don't think my original question was clear enough. Working back from the boiler towards the feed pumps, B31.1 122.1.7(B.1) requires a stop valve closest to the boiler, and then a check valve. On a boiler I've seen, the line was arranged with a stop valve at the...

Iaw B31.1 para 122.1.7(B.6), why can a combination stop check valve on the boiler feed line be considered only as a stop valve?

Thanks for your kind reply. I'll continue to pursue this with the manufacturers we have on our approved vendor list. To be honest, I'm not getting much help from them beyond "you might want to put it on a flow bench and check the performance before you install in the system"...

You have made it clearer. I've learnt something new today...

I'm not sure the fluid filling the grooves will stretch the seat passist. Each groove has a front and back face of equal areas. When the valve is pressurised, the force exerted on the front face of a groove will equal the force on the back face and the net result will be no movement.

Thanks for your considered reply Danlap. The system in question has a very high turndown ratio. I wonder if you have any guidance on sizing. (I wrote another post so apologies for asking the same question here.) I'm concerned about valve flutter/instability at low flow rates, but at the same...

Hi valve experts, I have a system with a high turndown ratio. We will use globe check and stop check valves in a couple of locations. I can find very little literature on how to size these check valves to ensure that they are fully open, or at the very least acceptably open, at low flow rates...

Hi valve experts, After scouring the internet and a couple of text books I have access to, I can't get a straight answer to this question. Given a straight pattern (ie vertical spindle tee pattern) globe stop check valve, and a wye pattern stop check valve, what are the relative advantages and...