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through the drain in the bottom of the housing. A plastic tube
is furnished for the condensate to be drained away from the
water heater.
A method to keep the condensate from draining back to the
blower, in a horizontal run, is to install the pipe with a slight
downward slope. The pipe can slope 1/4 inch per five (5) feet
of pipe, but no more than 1.5 inches in the total vent length.
The vent system should be supported every five(5) feet of
vertical run and every three (3) feet of horizontal run of vent
pipe length. All pipe and fittings should be joined by the proper
procedures discussed on pages 11 and 12, under the heading:
VENT PIPE PREPARATION.
VERTICAL VENT THROUGH ROOF
This unit is approved for venting through the roof with only the
vent terminal that is included with the unit. All proper flashing or
"BOOT" should be used to seal the pipe where it exits the roof.
The total vent system should not exceed that which is specified in
the chart on page 9.
All of the pipe should be secured as per the instructions in the
"INSTALLATION OF VENT SYSTEM" on pages 8 and 9.
VERTICAL VENT TERMINATION RESTRICTIONS
1. Minimum of twelve (12) inches above the roof or twelve (12)
inches above the anticipated snow level. Provide proper
support for all pipe protruding through the roof.
2. Four (4) feet from or one (1) foot above any gable, dormer, or
other roof structure with access to interior of building (i.e.-vent,
window etc.).
3. Three (3) feet above any forced air inlet located within ten (10)
feet.
FIGURE 8
VENT PIPE PREPARATION
1. INITIAL PREPARATION
A. Make sure the solvent cement you are planning to use is
designed for the specific application you are attempting.
B. Know the physical and chemical characteristics and
limitations of the PVC and CPVC piping materials that
you are about to use.
C. Know the reputation of your manufacturer and their
products.
D. Know your own qualifications or those of your contractor.
The solvent welding technique of joining PVC and CPVC
pipe is a specialized skill just as any other pipe fitting
technique.
E. Closely supervise the installation and inspect the finished
job before start-up.
F.
Contact the manufacturer, supplier, or competent
consulting agency if you have any questions about the
application or installation of PVC and CPVC pipe.
G. Take the time and effort to do a professional job.
Shortcuts will only cause you problems and delays in
start-up. By far, the majority of failures in PVC and CPVC
systems are the result of shortcuts and/or improper
joining techniques.
2. SELECTION OF MATERIALS
• Cutting Device - Saw or Pipe Cutter
• Deburring Tool, Knife, File, or Beveling Machine (2" and
above)
• Brush - Pure Bristle
• Rag - Cotton (Not Synthetic)
• Primer and Cleaner
• Solvent Cement - PVC for PVC Components and CPVC for
CPVC Components
• Containers - Metal or Glass to hold Primer and Cement .
Select the type of PVC or CPVC materials to be used on
the basisof their application with respect to chemical
resistance, pressure rating, temperature characteristics, etc.
• Insertion Tool - Helpful for larger diameter pipe and fittings
(6" and above).
PRIMER
It is recommended that Tetrahydrofuran (THF) be used to prepare
the surfaces of pipe and fittings for solvent welding. Do not use water,
rags, gasoline or any other substitutes for cleaning PVC or CPVC
surfaces. A chemical cleaner such as MEK may be used.
CEMENT
The cement should be a bodied cement of approximately 500 to
1600 centipoise viscosity containing 10-20% (by weight) virgin
PVC material solvated with tetrahydrofuran (THF). Small quantities
of dimethyl formamide (DMF) may be included to act as a retarding
agent to extend curing time. Select the proper cement; Schedule
40 cement should be used for Schedule 40 pipe. Never use all-
purpose cements, commercial glues and adhesives or ABS
cement to join PVC or CPVC pipe and fittings.
SAFETY PRECAUTION: PRIMERS AND CEMENTS ARE
EXTREMELY FLAMMABLE, AND MUST NOT BE STORED OR
USED NEAR HEAT OR OPEN FLAME. ALSO, USE ONLY IN A
WELL-VENTILATED AREA.
10
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