PVC-U Soil Bends — 87.5° and 45°
Bends change the direction of the stack or the horizontal run. The Marley range covers both the 87.5° bend used at the foot of a stack and for offsets, and the 45° bend used to create swept junctions and gentler changes of direction.
Also searched as: pipe bend, elbow, knuckle bend, swept bend, 90 degree bend, quarter bend
Angles and radius
Standard angles are 87.5° (commonly called a 90° or quarter bend on site) and 45°. Long-radius and short-radius patterns are available in the larger sizes. At the base of a discharge stack a long-radius bend, or two 45° bends in series, is strongly preferred over a single tight 87.5° — it reduces the hydraulic jump and the risk of the water seal in ground-floor appliances being blown.
Rest bends and offsets
A rest bend supports the foot of the stack where it turns into the horizontal drain and should be independently supported, not left hanging on the stack. Offsets in the stack are formed with a pair of 45° bends; check the offset rules in the Technical Manual before designing one into a tall stack.
Access
Where a bend is at the foot of the stack or at a change of direction in a concealed duct, use an access bend with a removable cover so the run can be rodded without cutting pipework.