A.O. Smith ProMax GPDX-50, Instruction Manual

Page: 21 / 36

21
FIGURE 30.
VENT PIPE PREPARATION
1. INITIAL PREPARATION
A. Make sure the solvent cement you are planning to use is
designed for the speci fi c application you are attempting.
B. Know the physical and chemical characteristics and
limitations of the PVC, ABS and CPVC piping materials that
you are about to use.
C. Know the reputation of your manufacturer and their products.
D. Know your own quali fi cations or those of your contractor. The
solvent welding technique of joining PVC, ABS and CPVC pipe
is a specialized skill just as any other pipe
fi tting technique.
E. Closely supervise the installation and inspect the fi nished
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, ABS 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, ABS 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” [5 cm] and above)
• Brush - Pure Bristle
• Rag - Cotton (Not Synthetic)
• Primer and Cleaner
• Solvent Cement - PVC for PVC Components and CPVC for
CPVC Components and ABS for ABS components.
• Containers - Metal or Glass to hold Primer and Cement. Select
the type of PVC, ABS or CPVC materials to be used on the basis
of their application with respect to chemical resistance, pressure
rating, temperature characteristics, etc.
• Insertion Tool - Helpful for larger diameter pipe and fi ttings 6
inches (15.2 cm) and above.
PRIMER
It is recommended that Tetrahydrofuran (THF) be used to prepare the
surfaces of pipe and
fi ttings for solvent welding. Do not use water,
rags, gasoline or any other substitutes for cleaning PVC, ABS 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
fi ttings.
APPLICATORS
Select a suitable pure bristle type paint brush. Use a proper width
brush or roller to apply the primer and cement (see chart below).
Speedy application of cement is important due to its fast drying
characteristics.
TABLE 3: RECOMMENDED BRUSH* SIZE FOR PRIMER
AND CEMENT APPLICATIONS
Nominal Pipe (IPS) Size Brush Width (INS.)
3 1-1/2 – 2-1/2
*USE ONLY NATURAL BRISTLE