Hong Kong Regulations

BUILDING (STANDARDS OF SANITARY FITMENTS, PLUMBING, DRAINAGE WORKS AND LATRINES) REGULATIONS - REGULATION 52

Ventilation

(1) Every drain provided for the carriage of foul water shall be ventilated at
its highest point by means of a ventilating pipe having an internal diameter
of not less than 50 mm. (L.N. 294 of 1976)

(2) Every manhole in which a disconnecting trap is fixed shall be adequately
ventilated.

(3) Branch drains shall be ventilated at their highest point, if the Building
Authority so requires.