100% radiography requirement on 150# Cast steel butterfly valve

[ET1983]

Does 100% radiography a mandatory requirement for standard class valves, 150 LB fire water service valve with cast steel body??
As per ASME B16.34, it states that, radiography is a mandatory requirement for Special class valves, so, can we interpret this statement that, no radiography is required for standard class valves.?
please clarify??

 

[gerhardl]

The main concern of a firewater system is how well the system as a whole will function in case of a fire. This will depend on both valve quality and dependability as well as the same for a number of other components and system engineering issues.

The other side is how large the consequences will be if (part) of the system fails, and if redundancy (ring systems?) present. The firewater could be for a small utility with a low content of materials that could burn, or for a large factory with a large degree of explosive and combustible materials. The total risk could be reduced by other, additional, methods for preventing or putting out a fire, for instance alarms, people/guards present, handheld devices, fire brigades nearby, and so on.

In my opinion I would require a lot of other functioning-, operating- and pressure tests, references and quality checks for producer valves and the system as a whole, before requiring radiographic inspection of a common low-class valve.

.....but I am not an expert on ASME!

 

[LittleInch]

Almost but not quite.

Section 2.1.2/3/4 lists the requirements.

A standard valve is in compliance with everything except section 8, where radiography is mentioned.

Special includes all the inspections in section 8

Therefore it is possible to have no radiography and therefore be a standard class valve.

for fire water you only need standard class valves.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Valveusa]

Is there are any new guide line about API Q1 and ISO 9001:2008
Quality Management Systems .

 

[bcd]

Standard class per ASME B16.34 does not require radiography. However, the customer can ask for it as an additional test.

 

[ET1983]

Thanks for your replies. It really means a lot.

 

[ary.prasetyo]

According to ASME B16.34, radiography is an option for standard class of valves. But if you confident with the casting quality you can ignore RT requirement and also the butterfly valve have a simple body design.