So ... if check valves rarely fail ... then there is a very slight advantage to have it protected by a gate valve. Other than a maintance issue, there is no other reason.
Thanks to all who replied and to those who reply after this email.
What are the reasons, if any, why anyone would prefer to locate the check upstream from the gate va? Or vice-versa. I am a designer and I am not sure if this matters at all.
Please chime in.
BTW, this is my first of hopefully many posts.
