Does a vent on a floor drain go before or after a p-trap?

does a vent on a floor drain go before or after a p-trap? Somebody gave you bad advice. Floor drains come with a built in trap and in my code area is the only fixture the doesn't require a vent./ However, your code may require a trap primer. Good luck, Tom

Depending on the application, vents are required on floor drains in my area. You install the vent before the trap (see drawing)... usually within 3 feet of the trap. A trap primer is also required in most cases.

Exactly what is the application you are installing this for?

Let us know more, OK?

Mark

So, we have two different answers. To see which one fits your case contact your local Building Department. Good luck, Tom