John Wood Superflue Power Vent (75 Gallon) - Manual (Page 15)

6. Calculate "Equivalent Vent Length" before starting. Do
not exceed the values shown in Table 2. An example of
how this length is determined is shown in Figure 8. The
value from your calculations should also be used to
determine which rodent screen to install into the vent
termination elbow.
7. Measure the vent piping and cut to required lengths.
Pipes must be cut at right angles and deburred to
ensure a good smooth fit with sufficient overlap for the
glue joints. Correct any interference conditions.
8. Provide support hangers for horizontal vent piping every
1.2m (4 ft.) to prevent sagging and stress. Provide a
minimum of 3mm (1/8 in.) rise per 1.2m (4 ft.) of vent
piping to ensure adequate drainage. Horizontal vent
piping must not sag to form valleys where condensate
may collect. Vertical venting shall be supported every
1.5m (5 ft.). Use appropriate support straps and vibra-
tion isolators (foam pads) on straight sections only. Do
not use elbows as support points. Allow sufficient clear-
ance for expansion and contraction of the venting sys-
tem.
9. At the point where the vent pipe exits the building, cut a
90mm (3-1/2 in.) hole for 76mm (3 in.) venting.
10. Insert the vent piping through this hole and secure into
position. Connect the vent pipe to the end termination
elbow as shown in Figures 9-12.
11. Dry fit all vent pipes, elbows, connectors and fittings
before joining any parts with solvent cement. PARTS
MUST FIT WITHOUT STRESS OR BENDING OF ANY
SECTION and each connection must overlap a mini-
mum of 13mm (1/2 in.). Do not force fit any of the con-
nections. Use only the appropriate solvent cement.
12. Install the properly sized rodent screen into the outlet
elbow and secure with a small quantity of silicone
sealant.
13. Do not seal the vent piping to the wall until the venting
is properly connected to the blower assembly.
Vent pipe connection to blower
1. The plastic vent piping connects into the rubber cou-
pling located on the top of the blower assembly. This
coupling includes gear clamps to connect the venting to
the blower. These connections must be properly seated
and tightened to prevent the leakage of flue gases into
the area. See Figures 13 & 14.
2. G/JW75 gallon heaters are supplied with a 76mm (3 in.)
adapter for installations using PVC vent piping. This
adapter must be used when using PVC piping. Securely
attach the PVC adapter to the first section of PVC vent
piping using the proper solvent cement before installa-
tion into the blower coupling.
3. G/JW75 gallon heaters using CPVC vent piping may be
connected directly into the rubber coupling.
4. Clean and lightly sand the end of the CPVC plastic vent
piping or PVC adapter that will connect into the rubber
coupling.
5. Loosen the upper clamp on the rubber coupling and
insert the sanded end of the CPVC vent piping or the
PVC adapter a full 32mm (1-1/4 in.). Do not use glue or
sealant in the rubber coupling. Check that there is no
stress on the connection or the vent piping that may be
caused by twisting or bending.
6. Tighten the upper clamp so that the vent piping is firm-
ly secured in the coupling and is gas tight. Do not over
tighten or cause distortion of any of the parts. Ensure
that the bottom of the rubber coupling is firmly seated
on the blower outlet and that the lower gear clamp is
also secure. Check to ensure that there is no distortion
or movement of the clamped assembly once it is com-
pleted.
– 15 –
PVC PIPE
COUPLING
76mm (3 in.)
ADAPTER
FOR PVC
Figure 13 Pipe Assembly Adapters
PIPE
(CPVC)
UPPER GEAR
CLAMP
RUBBER
ADAPTER
LOWER
GEAR CLAMP
TERMINATION
MAY BE 90°
ELBOW OR A
“T” ELBOW
76mm (3 in.)
MIN. LENGTH
ROOF
LINE
Figure 12 Vertical Venting
A VENT USED IN A SPECIAL
VENTING SYSTEM WITH
POSITIVE VENT PRESSURE
AND PASSING THROUGH A
ROOF SHALL EXTEND AT
LEAST
450mm (18 in.)
ABOVE THE HIGHEST
POINT WHERE IT PASSES
THROUGH THE ROOF SUR-
FACE AND ANY OTHER
OBSTRUCTION WITHIN A
HORIZONTAL DISTANCE OF
450mm (18 in.). A VERTICAL
VENTING SYSTEM MUST
BE SUPPORTED EVERY
2.4m (8 ft.).
RODENT
SCREEN
(INSTALL
INTO
ELBOW)
450mm
(18 in.)
CAUTION:
Use of Solvent Cement and Primer
• Use only in well-ventilated areas.
• Do not use near flame or open fire.
• Use only the Solvent Cement and Primer
appropriate for the venting material being
used.
• Solvent cements for plastic pipe are flam-
mable liquids and must be kept away from
all sources of ignition.