Durso symtoms

[pecan2phat]

Quick Q guys/gals,

When a dual Durso drain pipe system starts burping, is that an indication that the cap holes are too small?

TIA

 

[TheEngineer]

Can you clarify “burping”? Do you mean a big bubble every now and then in the sump or gurgling at the intake?

 

[pecan2phat]

I hear this big burp from both the overflow box and down in the sump where the drain pipe exits about once every 30~40 minutes. I think the level in the overflow starts to rise slowly over the durso pipe and then release the air possibly?
I tried taking off the caps and that just made the tank noise very loud so I made the hole the next size drill bit, wondering if I should go one more size up.

 

[TheEngineer]

That big bubble is accumulated air. That’s typical of a durso. It doesn’t have anywhere to go so it comes out in a big bubble. There are bubble buster approaches you can try.

Unless you’re getting the old durso flush I wouldn’t say drill the hole larger.

 

[pecan2phat]

Thanks for the info!

 

[ScottBrew]

Bigger vent hole = less water flow. Smaller vent hole = more water flow. You are using the air from the vent to slow down the water flow, which is the reason for using a durso style. Otherwise it would go into a full siphon every time the water rose in the weir then the full siphon would suck out all the water until it broke siphon again.