What is an ANSI Class 150 Valve? 2

[enuf4u]

I have a valve design that has pressure/temperature ratings per B16.34. The valve is not designed per B16.34, but it is a proprietary design at B16.34 pressure / temperature ratings. Marketing wants to call it a "ANSI Class 150 Valve". Does this imply that the valve is made to B16.34 or that the valve is rated at ANSI Class 150 pressure/temperature ratings?

Also, where did the ANSI Class designations come from. I know they are listed in B16.34, B16.5 and B16.47, but were they originally developed in another standard? Does anyone know of a standard that defines the Class designations? I found some thread on here that imply that the Class designations originated in the Boiler and Pressure Vessel Code. Does anyone have any insight on these two subjects?

Thanks in advance.

 

[vpl]

You might find this thread helpful: thread378-190880.

Other helpful threads can also be found by using the advanced site search feature, typing in your keywords, and selecting "full site".

Patricia Lougheed

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[JLSeagull]

Look for ASME instead of ANSI for current standards.

 

[DSB123]

JLSeagull,
Good post but your advise may fall on deaf ears as from my experience there are 80% or more in the engineering fraternity who still refer to ANSI rather than the correct ASME.

 

[vpl]

DSB123

It's usually because someone's been handed an old specification or drawing with the words "ANSI Class 150" and has never heard of that termonology.

In this case, I bet "Marketing" has a database that says if ordering valves per spec xyz, title it as "ANSI Class 150." The database has probably been around since the 1980's and incorporated information from the 60's or 70's... just my guess.

Patricia Lougheed

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[DSB123]

vpl,
Tend to agree with you. However there are those in engineering who do not keep up with the latest Codes. I am in the UK and constantly come across incorrect specifications being quoted "because it's been like that since Noah built the arc" and no checks are made to ensure Codes/Specs quoted are up to date one's.

 

[JLSeagull]

I suspect that well over 80% of the engineers and designers who refer to ANSI have never read the ANSI or ASME standards that apply. Most use an old Valve Catalog etc. I have become a "nut" about some of these codes and standards and try to pass some of my insanity along to the recent graduates. Many seasoned engineers and designers look at nomenclature like 4 NPS instead of 4" or Class 600 RF instead of 600# RF and are sure that I am nuts.

 

[JLSeagull]

NPS 4 might look better too.

 

[enuf4u]

I am still finding difficulty determining what an ANSI/ASME Class 150 valve is. My interpretation is that ANSI/ASME Class 150 refers to a pressure / temperature rating. This does not implicitly indicate that the valve is made to ASME b16.34. If the valve is made to ASME b16.34, then I would call it an ASME B16.34 valve. I am being pushed to make a decision on the semantics of this problem, but I cannot find any documentation to solidly support either side of the story.

Some of my co-workers believe that calling the valve an ANSI Class 150 implies that it is an ASME B16.34 valve. If I look at MSS SP-25 (Standard Marking System for Valves, Fittings, Flanges, and Unions) section 4.1, Rating Designation, I see: “The expression "Rating Designation" includes the intent of the expressions "Pressure Designation", "Service Designation", "Pressure Class", and similar terms used to define the pressure/fluid/materials temperature limitation of the product.” 4.1.1 further details Class as a rating designation: "The Rating Designation for products may be designated by the class numbers alone, e.g., a steam pressure rating or a pressure class designation." Is this valid documentation to support that Class 150 is a material/pressure/temperature rating designation?

Perhaps a better question is: What is the difference between an ANSI/ASME Class 150 Valve and an ANSI/ASME B16.34 Valve?

JLSeagul, I am feeling your insanity! This should be a simple subject with a simple answer... I am not the sharpest tack in the bunch, but I am by far not the dullest. There has to be something I am not seeing...

Thanks for all of your inputs.

 

[bcd]

If you use the terms ANSI or ASME class 150, you are exposing you company to a lawsuit. Whether intentional or not, for valves, it implies compliance with B16.34. Compliance with pressure vessel codes is the law in many states, and the codes refer to B16.34 as a governing standard for valves. It is the primary standard for valves in North America and much of the world. You must be very clear it what you are trying to tell your customer in stating "ANSI Class 150". If in anyway your marking can be considered intentionally deceitful, you are at legal risk. If someone misinterprets your marking, installs it in a code class plant, and there is a problem, there are legal implications. This is just my opinion as full compliance with B16.34 requires marking with the term "B16.34". B16.34 not only cover the pressure temperature ratings, but wall thicknesses, safety features, testing, marking, material, end connection dimensions, bolting, and more.

 

[JLSeagull]

ASME B16.34 applies to valves; ASME B16.5 applies to flanged fittings. I might interpret the term Class 150 valve to mean compliant with ASME B16.34. Let's say that a purchase specification required an API 6D ball valve with Class 150 RF fittings. Would this too be an ASME B16.34 valve? Perhaps the answer is yes; but you have to study API 6D and ASME B16.34 to assure compliance - and the flanges attached would need to comply with ASME B16.5. The term ANSI Class 150 valve seems erroneous or obsolete.

 

[enuf4u]

Does anyone know where or what standard class designations were first used? It seems to me that if I could uncover where the class designations originated from, I might be able to uncover the answers I am seeking...

 

[dcasto]

To add on to JLSeagull, by stating the Valve is a ANSI Class 150 would only imply that the bolting and flanges would match to another ANSI 150 class fitting. So, the statement only gaurentees that the valvel will bolt up and the flanges on the valve will not fail or be assumed as not failing.

I would assume that the title (ANSI 150) means nothing about how the valve operates or performs or if in fact it even had any internal parts. There are valves out there that do not "meet" either B16.34 or API 6D, but "performance" based testing has shown they do their intented service and will not fail. The valve manufacturer can always do the performnce based testing and publish their exceptions to API 6D that they do not comply with. This is what compressor manufacturers do all the time as very few compressor operators need 100% compliance with the standard.

As with any part failure, the manufacturer will be liable, the extent of liable all the way to criminal will be judged and only the OP's lawyers can give the OP that kind of opinion.

 

[vpl]

The classes come from ASME. You'd have to have access to old copies of the Codes if you're wanting to trace back to when they first developed and why.

Patricia Lougheed

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