3.2.8 Drain Pipe Work (Indoor)
! Operational steps
a) The drain pipe must be fitted at a gradient of at least 1/100.
b) Suspension bolts should be used to support long stretches of drain pipe in order to ensure
Spacing of supports for horizontal piping
c) The length of pipe laid horizontally should be kept to a minimum.
Fit any indoor unit whose drain pipe connection is subjected to negative pressure, with a drain
a) Rig the drain trap as shown in the drawing below.
b) Provide one trap per unit. A single trap for converging units will prove ineffective.
c) Rig the trap to allow for future cleaning.
Install indoor unit
The drain pipe should be as short as possible and free from airlocks.
that a gradient of 1/100 is maintained. (PVC pipes should not be bent)
Rigid PVC pipe
Connect drain pipe
H: 50 mm or more
Check for water
Gradient of at least 1/100
Insulate drain pipe