Flange to flange Double B & B ball valves 1

[Kensai]

Hi,

Does anyone know if there is a international standard for these valves?

 

[europipe]

Ballvalves in double bl & bl service are no difference from the normal ballvalves with built-in lenghts acc. to Ansi B16.5 B16.10 API602 BS5351 and DIN2501.

 

[MortenA]

Maybe you should also look at the DBB plug valves? They come as an integrated unit with the same build emasures as a standard ball valve.

Best regards

Morten

 

[dcasto]

I've never seen a true double block and bleed ball valve. Some models have a body blow down port and it looks and acts a lot like a gate valve that has two distict and powered (powered by cam or taped action)seals. Most balvalves will have a perfered pressurized end. Even the orbit valve is a specialized ball valve that uses a cam action to force a seal isn't a true DBB.

 

[MortenA]

Som tunnion mounted ball valves has a bleed between the seats, that enables testing of the seat tightness. Some vendors may use the term DBB for this feature - BUT ITS NOT! In a trunnion mounted valves the seats are only tight if there is a pressure difference - both upstream and downstream!

Best regards

Morten