Non Return Valve Is Driving Me Crazy

[weathermen]

I am nearly ready to load up pics and stuff but I have a problem,

The non return valve rattles like mad, the tank is 75 gal 340 litres the sump holds around 20 gallons, the pump running it is a Ocean Runner 2500, set up as follows

From Ocean Runner to 3 way ball valve (32mm) 10cm, from 3 way to first 90 degree elbow, then down a pipe 15cm then into another 90 degree elbow, up pipe around 30cm into non return then into a union then straight up into tank! I have tried the non return in a horizontal position and vertical, either way it rattles badly! Also tried reducing the flow with the 3 way valve “make no difference” any ideas???

It’s that bad my next door neighbour came round to say they can hear a noise through the walls, their bedroom backs onto the room with the tank!

 

[SkiFletch]

What is actually making the noise? Is it a flapper-type checkvalve and the flapper is constantly flapping? Or is the whole thing vibrating and hitting plumbing against the stand? Or is the sound more of an annoying humm? Also, is this a "Standard" under-tank sump? or is it somewheres else?

Pics and description of where the sound is originating from will help a lot

 

[weathermen]

Hi Ski!

pictures are not easy as the problem is behind the tank which is in a alcove! the problem is the check valve/non return valve, either the spring is rattling or the plastic disc which stops the water coming back to the sump is rattling, I have been advised to ditch the spring type check valve and go for a fully plastic one! I have purchased and will give that a go! the sound is like buttons been shaken in a tin! humming I can cope with, I have fans in the hood and they are ok, but this is horrible!
I'll keep you posted!

thanks again

 

[SkiFletch]

Oh you have a spring type? Yikes, those rarely work well in our marine applications. Get the flapper-type in there, should help a lot. And when you're in there, make sure the plumbing isn't rubbing up against the stand/wall/etc.

 

[weathermen]

Great advice

cheers, lets hope the new one arrives today and does the job!