Return to the Plumbing Forum | Post a Follow-Up

 o
Why Water Line Connected to Sink Trap?

Posted by lrm11241 (My Page) on
Tue, Sep 17, 13 at 17:39

While traveling in California, I noticed in the bathroom of my hotel that a water line came out of the wall (with no valve) and was connected to the P trap under the sink. This was the same type of supply line used for the hot and cold water service. The trap was made of metal. Please see attached photo.

I am unable to come up with a function for such a supply line between the wall and the trap, and I have been unable to find anyone who knows the function around where I live.

Does anyone know what this line would be for?


Follow-Up Postings:

 o
RE: Why Water Line Connected to Sink Trap?

It's called a water-prime and is required where there is a potential for the water present in the trap in normal use, evaporates due to a lack of use, IE.vacancy.

These are also found in floor drains.

The water in the trap serves the function of preventing the sewer gasses from migrating to fresh air.


 o
RE: Why Water Line Connected to Sink Trap?

Trap prime.
As mentioned above, used to keep the basin/tub/shower/floor drain trap water seals intact. Might be needed in arid areas with high heat, low humidity, high winds combined with marginal venting systems situations emptying traps, or combinations of similar conditions.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Plumbing Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here