– 41 –
Connection of Drain Tube
1. Fit the coupling pipe at both ends with a hose band.
2. Fit one end of the provided coupling pipe over the discharge port of the drain-up kit. Insert PVC tube VP-20
into the other end of the coupling pipe. Secure the connected pipe and the tube with a hose band.
Fig. 10-1-5
Tightening allowance
for hose band: 8-10 mm
10 mm
10 mm
VP-20
Insert 35 mm or more
Drain-up kit
Discharge
port
Hose band
5
Coupling pipe
4
1/100-grade or steeper
downwar d slope of VP-20
Insulation
material
No trap allowable
3. Make sure that the coupling pipe is tightened 8-10 mm using the
hose band.
4. Wrap the VP-20 drain tubing in the insulation material.
5. Wind the coupling pipe in the provided insulation covering with
its joint facing upward. Using the hose band, tighten the insula-
tion covering until there is no clearance left.
• Use the hard PVC tube VP-20 for the drain tubing.
Apply a PVC-based adhesive to joints to prevent water from
getting out.
• Apply the insulation material (10 mm or thicker wall of
formed polyethylene) to the drain tubing arranged indoor.
• Secure a section of the drain tubing near to the drain-up kit so
that no unnecessary force is applied to the drain tubing.
Fig. 10-1-6
*
Finally allow the water from the heat exchanger to flow through the installed drain tube to make sure there is no
problem with the drain system.
Keep the following in mind
• The drain tubing should have a downward slope (1/100 or steeper) toward the outlet.
There may be no up-and-down or other intervening trap for the flowing water.
• The length of the drain tubing arranged horizontally must not exceed 15 meters.
• The drain tubing must not have an upward slope from the outlet of Drain-up kit.
• The end of the drain tube must not be immersed in water or located 50 mm or more above the ground.
1/100 or steeper
downward slope
VP-25
End of drain tube
immersed in water
Draining
trench
50 mm or less clearance
relative to the ground
NO GOOD
Greatest possible gap (approx. 100 mm)
Fig. 10-1-7
*
VP-20 : PCV tube
of inner dia. 20mm.
