On Thursday, December 19, 2013 3:06:58 PM UTC-5, wrote:
On Thursday, December 19, 2013 2:48:47 PM UTC-5, TimR wrote:

On Thursday, December 19, 2013 10:34:33 AM UTC-5, wrote:



Sigh, and completely different settup. It's kind of the reverse of a







P-trap.







It's certainly a U-trap though, and even in a plumbing P trap all the water is in the U.







Hmmm.......?



Why don't you think of the design of the two, how they operate

and get back to us. For starters, a bong is not a U trap. It's

not designed to block air/gas flow. It's designed to make air with

burning smoke bubble up through water when pulled via a vacuum.

So to say that because a bong passes smoke as it's designed to do

somehow means that a P trap isn't effective at sealing out gases

makes no sense.

The pressure at the bottom of an inch of water is ,036 psi

How much vacuum do you think it would take to pull a gas up through an inch of water (or less) in a trap?