Vent hole instead of a check valve?

[poconojoe]

My bog is higher than my pond and the pvc flex goes over a dividing wall between the bog and the pond. The PVC flex connects to ridgid PVC above the gravel in the bog.
I remember reading that some of you make a vent hole in a pipe that sits above the height of the water so if the power goes out the water doesn't drain back to the pump.
I'm interested in this because I'm afraid if I use a check valve it may get clogged with debris.
So, what size hole do I drill in an 1-1/2" pvc? And won't the water shoot out of the hole when the pump is running? I guess if the hole is pointing in the right direction it won't matter.

 

[mrsclem]

I use 1/8" hole slightly below the water level in the bog. It does spray but I have a large stone in place to block it. It allows the water level to drop about 1/2" and then suction is broke.

 

[GBBUDD]

the hole is a quick easy way to stop the siphon but you need to keep in mind it is always spitting out water as well. there is another tool similar to check valves that you can use along with check valves. it's works in reverse of a check valve where the flap is opened by the water pressure. this works in reverse it closes the check valve and when the power drops out it no longer has the pressure to hold the valve shut . cheater valves is one name for them or a sure vent . the problem with the hole is it can get clogged but then again so can the sure vent.

 

[Mmathis]

the hole is a quick easy way to stop the siphon but you need to keep in mind it is always spitting out water as well. there is another tool similar to check valves that you can use along with check valves. it's works in reverse of a check valve where the flap is opened by the water pressure. this works in reverse it closes the check valve and when the power drops out it no longer has the pressure to hold the valve shut . cheater valves is one name for them or a sure vent . the problem with the hole is it can get clogged but then again so can the sure vent.

What is it called?

I don’t recall what size holes I drilled, but somewhere in the 1/8” to 1/4” range.

 

[GBBUDD]

What is it called?

I don’t recall what size holes I drilled, but somewhere in the 1/8” to 1/4” range.

Cheater vent or a sure vent

 

[Chucker's 50]

The Sure Vent is also called an Air Admittance Valve

 

[IPA]

This is the check valve I use. I’ve had to purchase many over the years for our irrigation well and I believed this was superior to spring or vertical designs. My intake is mounted about 8 inches from the bottom with a inexpensive but good debris filter that is pretty much self cleaning.

as installed; the ball valve is redundant and not necessary as far as my experience goes.