Trap Primer Selection

[DianaVu108]

Hi, I'm new to Plumbing and I'm looking at some old projects at my company to learn more about selecting equipment and plumbing fixture.
For automatic trap primer, some projects use Mifab M-500, which will activate by the pressure drop of 3 p.s.i, but I also saw some projects that used the CPO-500 which requires a 10 psi pressure drop across the valve to activate. So which one is a better one ? and what is the pressure drop for every toilet flush. Is there any difference between the two besides the pressure drop?

Thanks,

 

[PEDARRIN2]

PPP, which manufactures the CPO-500 is known for trap primers and a few other things. Mifab is a bit more broad scoped, offering floor drains, fixture carriers, etc. So, when specifying or when purchasing, name recognition is important. Price is also important. It looks like the CPO-500 is mainly copper whereas the M-500 is stainless.

The Mifab unit might have been specified because other Mifab equipment was being specified which would tend to lend itself to getting a better price due to a bulk order.

It also looks like the M-500 will likely also initiate when the cold water to the lavatory faucet is used.

As to which is better - that is a question which is debatable. Trap primers are a maintenance issue, especially in areas with hard water. Because traps have to be primed, they are included. But often owners will remove them after occupancy so they don't have to maintain them.