Maxium Desgin temperature, API 620

[Pato12]

Hello,

Just wanted to ask for your advice guys on the maximum design temperature of stainless steel tanks in API 620.

Its says the following,

"Its up to the purchaser to specify the maximum temperature, not to exceed the 120 deg C."

Now in my case I need a storage tank that is at 500 Deg C.

Am I covered by the API 620 standard for storage of low pressure storage of high temperature liquids?

Pato

 

[JStephen]

Neither API-620 nor API-650 include temperatures that high. ASME does, but doesn't include provisions for typical flat-bottom construction.

 

[Pato12]

Oh, would you happen to know what the name of the asme standard that includes high temperature storage tanks.

I'm really lost and I cant seem to find it.

 

[fegenbush]

It is not a storage tank code, but the above reference is to ASME Section VIII Division 1 Rules for Construction of Pressure Vessels.

 

[Pato12]

pressure vessels?

hum this seems should wrong to me because the pressure requirements are no where that high to warrant a tank to be fabricated like a pressure vessel as my tank is just above ambient(slightly to avoid air entering) and is quite large.

 

[JStephen]

The different tank and vessel codes have been set up for the common tank/vessel applications. If you have something very out-of-the-ordinary, it may not fit any of those codes very well. The API standards were written for petroleum storage, not for molten salt storage, and are limited to conditions typically encountered in the petroleum industry. The boiler and vessel codes are more general, but also don't offer specific guidance for many design problems, so they are less useful as for a cookbook approach.

The design methods for hydrostatic loading, etc., from API-650 or 620 would be appropriate for any tank of the shapes and pressures included in those standards.

The ASME Boiler and Pressure Vessel Code includes allowable stresses at elevated temperatures.

Neither of those give detailed design for thermal stresses, etc., which would be the major concern there.

It would be very helpful to have someone familiar with design, construction and operation of similar large "hot" equipment involved on your project. Learning from scratch could be expensive.

 

[Ripz]

Pato12. What's your operating pressure? Anything above 15 PSI is considered a pressure vessel as per ASME Section VIII Div 1.

 

[Pato12]

10 mBar, is my operating pressure.

and 500-600 is my operating temperature.

thanks for your reply guys I understand there is a degree of my own engineering judgement that has to be applied here because this tank is unique. I have designed other aspects of the system under high temperature in the project and they are purely trade secrets on how they were designed and there are no codes. They are patient worthy if you know what I mean.

But the only reason I'm interested in making sure I use any and all standards regarding tanks is due to maintenance and the severity of catasopopic failure. The other devices in the system are expected to repture after so many hours of operation. Creep and rupture are the only things you really care about when it comes to high temperature induced stresses.

I guess I will have to mic and match between the api 620, asme boiler & pressure vessel codes. There are other more standard things that you must consider as we all know such as anchorage etc..

thanks for your help guys, guess I'm on my own.

 

[JStephen]

In the process, be sure and refer to Appendix M of API-650, and also it references a couple of technical papers that may be of interest.

I recall reading about a very large tank for similar temperatures built a while back. I believe it was in Spain, but not sure. It was for molten salt for thermal storage for a solar plant, if I remember right. So similar things have been done, just not enough to get codified.