Conduit Bends & Inspection Bends
Bends turn the conduit run. The choice is between a moulded bend, which is quick and consistent, and a cold-formed bend made on site with a bending spring, which avoids a joint and keeps the run continuous for cable pulling.
Also searched as: conduit bend, plain bend, solid bend, inspection bend, access bend, elbow, 90 degree bend
Plain and inspection bends
A plain bend (also called a solid or normal bend) is a sealed moulded 90°. An inspection bend has a removable cover, so cables can be drawn in and inspected at the turn — specify these at points where a pull would otherwise be difficult. Codes AEMNB2 to AEMNB6 cover 20 to 50mm.
Cold bending on site
Conduit up to 25mm can be cold bent using the correct size and gauge of bending spring. Heavy gauge springs are colour-banded red at the tip, light gauge blue, and the two are not interchangeable. Insert the spring to the position of the bend, grip either side and bring the ends slowly together. Make the bend slightly more acute than needed to allow for the PVC-U recovering after release.
Bend radius
Care is needed not to make too tight a bend. BS 7671:2018 Section 522.8.3 requires the radius of every bend in a wiring system to be such that conductors and cables are not damaged. In cold weather, warm the conduit by rubbing with a rag before bending.
Removing the spring
Twist the spring anticlockwise to reduce its diameter while turning the conduit clockwise, and pull gently. If it does not release, repeat rather than forcing it — pulling hard damages the spring and can kink the conduit.