My new check valve is not working as it should

[GBBUDD]

@Landman

I believe what I am hearing is a steady thumping sound about every 2 seconds that lasts until the bog has emptied itself back into the pond. So your description of water hammering seems correct, however, that isn't supposed to continue in a steady pattern like I am experiencing. Water Hammer typically happens once when the valve is closed, and then ceases.

It is a shame that your flap sits sideways. I agree that would cause a problem. My check valve is vertical so that is not my problem.

I WONDER IF YOU HAVE A HORIZONTAL CHECK VALVE AND NOT A VERTICLE. you placed the check valve in the right location so as to have enough head pressure to do the job but your flap is not seating properly. It is possible to have air entering from the intake ? like @Landman Suggests if you do not have one you could place a check valve on the intake line so when you loose power water stays in the intake line so you'l want the check valve toward the intake source

 

[CHY]

I 100% have a vertical one sitting atop the pump outlet.

I do intend to place a second (horizontal) one near to bog and see if the two working together might solve this. I don’t know what else to try at this point.

 

[GBBUDD]

replace the one you have with another make dont buy the same. i have never seen the one you have , thankfully