why does sink drain gurgle?

[frankg]

I moved our kitchen sink and of course had to redo the abs trap and drain connection. Everything works ok but I'm curious why the drain seems to gurgle (for lack of a better descriptive word) after the water has run out. And it also sounds like it's dripping after theres no more water in the sink to run out. Can you suggest a reason and cure ?

thanks
Frank

 

[Speedy Jim]

I moved our kitchen sink and of course had to redo the abs trap and drain connection. Everything works ok but I'm curious why the drain seems to gurgle (for lack of a better descriptive word) after the water has run out. And it also sounds like it's dripping after theres no more water in the sink to run out. Can you suggest a reason and cure ?

thanks
Frank

The Gurgle is caused by the water in the trap attempting to self-siphon out. And that suggests that moving the sink connection has disrupted the venting of the trap.

Either the trap is now too far from the San TEE and vent or the slop is too great. Or, in the case of sinks which have no vent connection, the horizontal branch is too small to allow air circulation (this kind of self-vent is no longer used but was common up thru the 50's.)

You may be able to fix the problem by adding a mechanical vent just downsrtream of the trap.

Jim

 

[cowboy]

venting issue

 

[frankg]

solution : by adding a mechanical
vent just downsrtream of the trap.

since it's all glued ABS , how do you add a "mechanical vent" - is that a piece you buy and attach to the ABS ?

 

[Speedy Jim]

solution : by adding a mechanical
vent just downsrtream of the trap.

since it's all glued ABS , how do you add a "mechanical vent" - is that a piece you buy and attach to the ABS ?

Have to cut a section of ABS out and insert a San TEE
with the Mech vent sticking up.
Jim