Double Check Valve

Dear Group,

For a certain job, double check valves of different types are specified in series for providing high integrity.

There are 2 systems in which this is required.

1. A 16" 900# pump discharge. Where the desirable objectives is to have 1 even if the other is to pass in reverse flow.
2. A 18" 600# booster station bypass. Where the objective is also as above and in addition to be able to maintain without having to remove the valves from the line.

I am inclined to specify as below,

1. (a) A double disc spring loaded flanged check valve. (b) Axial flow piston type (Nozzle check) http://www.petrolvalves.it/products.asp?id=42.
2. (a) A swing check with external damping. (b)

For (b) in 2 is there another type which will allow the removal of the internals such as is possible with the swing check through the bonnet.

Sajit Received on Tue Jun 15 06:08:00 2004