Level bridle design on 450# steam drum

[DbyC]

I need some clarification regarding requirements on level bridle isolation valves.

ASME Section 1 Steam Drum

My current configuration has double isolation between the drum and water column. One valve is a quarter turn ball valve and the other is a gate valve. The ball valve was added two or three years after original construction. I don't have much info on this valve.

I've always used gate valves for this purpose and globes for blowdown. Does this ball valve meet code?

 

[unclesyd]

Our standards allow no 1/4 turn valves on or near our boilers. If I recall correctly all other valves associated with ancillary equipment are globe or needle vales. Only the larger valves a gate valve and above a certain size have to have a built-in bypass or warm up configuration.