(1)
Every oil interceptor shall be provided with 2 vent pipes that
(a)
connect to the interceptor at opposite ends,
(b)
extend independently to open air,
(c)
terminate not less than 2 m above ground and at elevations differing by at least 300 mm, and
(d)
do not connect to each other or any other vent pipe.
(2)
Adjacent compartments within every oil interceptor shall be connected to each other by a vent opening.
(3)
Where a secondary receiver for oil is installed in conjunction with an oil interceptor, it shall be vented in accordance with the manufacturer’s recommendations, and the vent pipe shall
(a)
in no case be less than NPS 1½,
(b)
extend independently to open air, and
(c)
terminate not less than 2 m above ground.
(4)
The vent pipes referred to in Sentence (1) are permitted to be one NPS smaller than the largest connected drainage pipe but not less than NPS 1¼, or can be sized in accordance with the manufacturer’s recommendations.
(5)
A vent pipe that serves an oil interceptor and is located outside a building shall be not less than NPS 3 in areas where it may be subject to frost closure.
(6)
Every grease interceptor inlet pipe shall be provided with a vent pipe
(a)
within 1 500 mm of the inlet to the grease interceptor,
(b)
not less than NPS 1½ for inlet pipes up to NPS 4, but not larger than NPS 2, and
(c)
complete with a cleanout to provide cleaning of the vent pipe.
(7)
Where an acid waste dilution tank is installed, it shall be provided with a vent pipe connected at the top of the tank and that is sized in accordance with Article 7.5.7.7.