Trap Primer - Advice Requested

[dz63]

Guys

• I am replacing a counter-top and 3 basins/facets in our church washroom.
• Planning to use china basins with Moen L64600 single lever lav facets.
• One of the 20 year old existing facets has what looks like a trap primer. See photo below.

• There is a 1/4" OD or 3/8" OD flexible copper tube coming out of the middle hole in the basin, going into the wall and then comping back out of the wall and discharging into an 1/2" rigid copper pipe with an "open" connection.
• I suspect there is a trap primer behind the drywall and the open connection is a vacuum break.
• I am not sure why there is a third line coming from the facet. Maybe the old trap primers had to be fed from a line from the facet?
• My plumbing wholesaler says I need to buy a Zurn Z-1022 automatic trap primer.

My questions are as follows:

• Where do I install the Zurn Z-1022 and what do I do with the old trap primer behind the drywall - cut it out?
• The Zurn instructions say I need 20-80 psig and 2-3 psig pressure drop for this to operate properly. I have 50 psig supply at the church but the facet has a 0.5 gpm flow restrictor (we have limited hot water). Do you think I will get enough pressure drop with a 0.5 gpm flow restrictor ?
• The instructions say that there must not be any "dips" in the primer line feeding the drain. Is it pretty safe to assume that the plumber who installed this knew what he was doing and installed the primer line with no "dips"? See instructions below...

Thanks, Don

 

[Jadnashua]

There's more than one company that makes trap primer valves, but I do not know what is available in Canada. Any of them will have some similar operational properties.

 

[Sponsor]

 

[Smooky]

Your existing trap primer is part of the faucet. When the faucet is used a little water goes to the floor drain. The little pipe was just looped into the wall for support and then covered with drywall. You will need to tie into the cold water line with a new trap seal primer.

Here is one that is designed to go under a lavatory:
http://www.pppinc.net/1/2/under_lav_trap_primer.html

Here are some others:
http://www.pppinc.net/1/2/trap_primers.html