Flounder wrote:I am at a loss for the required information for the valve information. I plan to use Mcmaster Carr part number 6646K23 That I have seen used for several builds on the forum all ready. Any advice you can provide would be appreciated.

This should give you a very good approximation:

Thank you for that information. I had to poke around to find how to change Flow Coef to Cv instead of %.

On to another question. Has anyone tried using a slide gate valve for a breech? I have found a few but they only have a 40 psi rating. I think that would be ok since I am running relatively low pressure in this thing, but I was hoping for input from the people who have been doing this a long time.