2004 Product Data 75
14. Installation
14.5 Drain Pipe Work
❑ Drain pipe gradient and support
1) - The drain pipe must be fitted at a gradient of at least 1/100.
- The drain pipe should be as short as possible and free from airlocks.
2) Suspension bolts should be used to support long stretches of drain pipe in order to ensure that a gradient
of 1/100 is maintained.(PVC pipe should not be bent)
Spacing of supports for horizontal piping
3) The length of pipe laid horizontally should be kept a minimum.
❑ Drain trap
Fit any indoor unit whose drain pipe connection is subjected to negative pressure, with a drain trap.
1) Rig the drain trap as shown in the drawing below
2) Provide one trap per unit. A single trap for converging units will prove ineffective.
3) Rig the trap to allow for future changing.
Class Nominal diameter Spacing
Rigid PVC pipe 25~40mm 1.0m or less
Indoor unit
Gradient of at least 1 / 100
(1cm/ 1m)
Indoor unit
H: 50mm or more
H
H
Indoor unit
Plug
Indoor unit
Plug