Interpretation of word " recommended " in ASME BPVC Code 6

[Some Curious Guy]

I have two queries. One specific and the other general.

Specific Query : -
In Appendix 2 of ASME Sec 8 Div 1 there is table of recommended gasket width. I have attached a snap shot. I want to know how do I interpret the word recommended. Does it mean mandatory or it's optional.

General query : -
I wonder if ASME Boiler Pressure Vessel code anywhere defines the term " Shall " , " Should " , " recommend " . I have seen some specification define Shall as mandatory. Should as not mandatory but recommended. Does ASME code have something like this.

 

[SnTMan]

Some Curious Guy, those words are defined in any dictionary...

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[TGS4]

It is not mandatory. Nevertheless - imagine that something goes wrong and something catastrophic happens. You are called to testify in front of a judge. An attorney asks you this question while you are under oath: "The Code from the American Society of Mechanical Engineers, which represents the best of the industry made a recommendation of a value to be used. You chose to use a different value. What information do you have that the industry participants didn't have? What made you so certain that your judgement was better in this situation than the collective judgement of all of those engineers?"

If you can answer that question confidently, then carry on. If that causes you to pause, well then...

 

[Some Curious Guy]

BPVC code is treated as a legal document and hence we see some very unique interpretation depending on whether you read it as a lawyer or Engineer.
Thanks TSG4 and SnTMan for your replies. I really have much respect for your knowledge , experience and expertise.

 

[SnTMan]

Some Curious Guy, there is often a "lawyerly" component to interpreting Codes, specifications and so forth. We generally deal with this in one of two ways:

1) Select the most conservative interpretation and get on with life
2) Seek an interpretation / confirmation from the appropriate party

Best of luck

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[TGS4]

Depending on where you are (or more specifically where the pressure vessel will operate) in the world, the ASME Code indeed is the law. And even if it is not, there is the whole "duty of care" that we as engineers owe to the public. That is a very serious duty and should be treated with the utmost care.

 

[DekDee]

SCG,
Read the codes.
That is the only way for you to learn.

ASME B31.3
shall: a term that indicates a provision is a Code requirement.

should: a term that indicates a provision is recommended
as good practice but is not a Code requirement.

ASME VIII Div 1
shall: “shall” or “shall not” is used to indicate that a
provision or prohibition is mandatory.

should: “should” or “it is recommended” is used to indicate
that a provision is not mandatory but recommended
as good practice.

 

[DriveMeNuts]

The term 'recommend' may be in the code because the ASME committee recognise that a rule is not suitable in all circumstances.

Do a lot of research before deviating from the recommendation and ask yourself "what will my explanation to the court judge be if it fails?".