Vent Pipe Preparation - A.O. Smith RESIDENTIAL GAS WATER HEATERS Instruction Manual

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 t he p hysical a nd c hemical c haracteristics a nd l imitations o f t he
PVC and CPVC piping materials that you are about to use.
C.) Know the reputation of your manufacturer and their products.
D.) Know y our o wn q ualifications o r t hose o f y our c ontractor. T he s olvent
welding t echnique o f j oining P VC a nd C PVC p ipe i s a s pecialized s kill
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 basis of their
application with respect to chemical resistance, pressure rating,
temperature characteristics, etc.
•
Insertion Tool - Helpful for larger diameter pipe and fittings 6 inches
(15.2cm) 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.
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.
IMPORTANT NOTE: A dauber type applicator should only be used
on pipe sizes 2" and below. For larger diameter pipe, a brush or roller
must be used.
RECOMMENDED BRUSH* SIZE FOR PRIMER
and ceMent applIcatIons
Nominal Pipe (IPS)
2
3
*use onlY natural BrIstle
3. MAKING THE JOINT.
A.) Cutting Pipe must be squarely cut to allow for the proper
interfacing of the pipe end and the fitting socket bottom. This
can be accomplished with a miter box saw or wheel type cutter
Wheel type cutters are not generally recommended for larger
diameters since they tend to flare the corner of the pipe end. If
this type of cutter is used, the flare on the end must be
completely removed.
NOTE: Power saws should be specifically designed to cut plastic pipe.
26
Size Brush Width
1.5" (3.8cm)
1.5"-2.5" (3.8cm - 6.4cm)
step a