A Studor vent is simply a valve that allows air into drainpipes when suction is present. The vent closes when the suction disappears to prevent foul odors from coming back into the building. Often, when a bathtub, shower or washing machine is bubbling or gurgling, either a Studor vent needs to be installed or an existing vent is locked in the open position.

Bathtub In Bathroom
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Studor vents help to facilitate drainage in bathtubs and showers.

Step 1

Use the Studor Maxi Vent on drainpipes from 3 to 4 inches.The vent is manufactured primarily for commercial buildings, and is the largest one made by Studor, with a correspondingly large venting capacity. It can be "stacked" to provide additional DFU (drainage fixture capacity, a drainage measurement set forth by the Uniform Plumbing Code).

Step 2

Vent as much as 160 DFU with the Studor Mini Vent, the type most commonly used in the household. This type is also equipped with an anti-rodent feature that can reduce extermination costs over the life of the product, according to Studor's website. Use this type of vent on 1 1/2- to 2-inch piping.

Step 3

Add a Studor Ultra Vent in more constricted spaces. At 20 DFU, this vent has a smaller drainage capacity than the other models, but 20 is actually plenty for any single bathroom, sink or washing machine.