7.2.4.3.90° Elbows

(1) Except as permitted in Sentences (2) and (3), 90° elbows of NPS 4 or less whose centre-line radius that is less than the NPS of the pipe shall not be used to join 2 sanitary drainage pipes. (2) For sanitary drainage systems of NPS 4 or less, 90° elbows described in Sentence (1) shall only be permitted (a) to change the direction of piping from horizontal to vertical, in the direction of flow, (b) where a trap arm enters a wall, or (c) to connect trap arms as permitted by Sentence 7.5.6.3.(2). (3) A 90° elbow that is part of the pre-engineered wastewater heat recovery system is permitted to have a centre-line radius that is less than the size of the pipe.