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2012 International Residential Code (IRC)

SECTION P3105 FIXTURE VENTS

P3105.1 Distance of trap from vent. Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table P3105.1.

Exception: The developed length of the fixture drain from the trap weir to the vent fitting for self-siphoning fixtures, such as water closets, shall not be limited.

Se você estiver usando uma armadilha de 1 1/2 ", deve haver uma ventilação dentro de 6 'do duto de armadilha. O comprimento total do dreno também é limitado com base no tamanho do tubo (P3105.2).

P3105.2 Fixture drains. The total fall in a fixture drain resulting from pipe slope shall not exceed one pipe diameter, nor shall the vent pipe connection to a fixture drain, except for water closets, be below the weir of the trap.

Então, se você estiver usando PVC de 2 ", o dreno deve ter menos de 8 'de comprimento na horizontal.

1/4" * 8' = 2"