Sewage ejector pump making a very loud banging noise after it shuts off.
In my basement I have a sewage pit for my bathroom/kichen. After the ejector pump shuts off it makes a very loud bang that can be heard throughout the whole house. The discharge pipe is 2" and is approximately 7' from the top of the pit to the ceiling where it makes a 90 degree to the main discharge pipe. I have a vertical valve installed about 5' up the discharge pipe. How can I eliminate this band which sounds like a bomb went off in the basement?
Thanks.