DB&B VALVES 2

[SIMA85]

Hi
I have a very very urgent question about application of double block & bleed valves,single block & bleed valves ; where and for what working classes these are necessary ?
My question is for a crude oil metering system and the maximum working class is 600# ; please inform me about some site addresses

thanks a lot

 

[dcasto]

I've had a running debate in the chemical industry that a DBB valve is not adequate and only spectcle blinds can be used. I agree with the blinds if the fluid is posionous or such, but typical hydrocarbons and steam the DBB is fine. I though biginch may have been on that side of the debate.

 

[MortenA]

I think we agree then. I know refineries where only blinds are accepted (and steam out prior to entry). But offshore DBB seems accepted for parallel trains.

Best regards

Morten

 

[29041970]

What is the meaning of Full bore and Reduced bore in DB&B valves? Where can I get a cross section drawing showing the differences?

 

[Ashereng]

Full bore means the full diameter of the end connections.

Reduced bore means it is smaller. You need to check each valve manufacturer's definition of reduced bore, but it is usually the next size down.

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