Backflow Preventer Valves

[jamz2603]

I have a customer wanting to change the valves on an existing backflow from Butterfly to OS&Y for their sprinkler system. I was always under the understanding that you cannot simply change out the valves but would have to change out the entire assembly, otherwise it would become unlisted. Am I correct in thinking this?

 

[cdafd]

I would say you would be correct if the backflow was tested with the valves

Most of the cut sheets do not show valves attached to the backflow

I would say no problem

 

[PEDARRIN2]

Most backflows are considered assemblies and tested as such. Typically that would mean to change the valve would change the assembly - and void the listing/rating.

But if the valves were changed to a type that was tested as part of another assembly by the backflow manufacturer - that might work.

 

[jamz2603]

Thank you, I appreciate the comments.