Burnham 20_PV_I - Manual (Page 11)

11
D. Install Vent Pipe, General.
1. Start at vent connector. Work toward vent terminal.
2. Use ¾ inch pipe strap to support horizontal runs,
maintain vent location and slope, and prevent sags.
Do not restrict thermal expansion movement.
Maximum support spacing is 5 feet.
3. Provide minimum 5 inch clearance to combustible
materials. Use thimble when penetrating
combustible wall.
a. 203PV and 204PV - Single wall thimble,
Burnham Part No. 8116116. Other wall thimble
manufacturers are American Metal Products,
Hart & Cooley, and Metal Fab.
b. 205PV and 206PV - Double wall thimble,
Burnham Part No. 8116115 (accomodates 5" to
8¾" wall thickness). Another wall thimble
manufacturer is Hart & Cooley.
4. Cut pipe to length using hacksaw with minimum 32
teeth per inch or circular saw with metal abrasive
wheel. Remove bead end only - bell end accepts
next fitting or pipe. Cut must be square with pipe.
Scrape off burrs with sharp edged tool.
Note: If remaining pipe (less bell) must be used,
beaded end of mating pipe/fitting must be crimped.
5. Seal all joints using Dow Corning Silastic 732
RTV, Dow Corning Silastic 736 RTV, Polybac
#500 RTV, or Sil-bond RTV 4500 (Acetoxy). Do
not use other adhesives or sealants.
6. Procedure for joining pipe and fittings. See Figure 8.
a. Clean pipe or fitting. Remove all dirt and grease.
b. Slip locking band over pipe/fitting bell.
c. Apply continuous ¼ inch bead of sealant around
bead end of pipe/fitting no more than 1 /
8
inch
from end.
d. Insert pipe/fitting into bell. Smooth sealant for
continuous seal around gap between bead and
bell. Apply additional sealant if necessary.
e. Slip locking band over joint and tighten. Do not
secure joint with sheet metal screws or pop rivets.
E. Horizontal (Through Wall) Vent Installation.
1. Maintain minimum ¼ inch per foot slope in
horizontal runs. Slope pipe down toward vent
terminal.
CAUTION
Moisture and ice may form on surfaces around
vent terminal. To prevent deterioration, surfaces
should be in good repair (sealed, painted etc.)
2. Vent terminal location restricted per following:
a. Minimum 12 inches above grade or normally
expected snow accumulation level, or 7 feet
above grade if located adjacent to public
walkway. Do not install over public walkway
where local experience indicates condensate or
vapor from Category III appliances creates a
nuisance or hazard.
Figure 8: Typical Joint Detail
b. Minimum 3 feet above any forced air inlet
located within 10 feet.
c. Minimum 4 foot below, 4 foot horizontally
from, or 1 foot above any door, window, or
gravity air inlet.
d. Minimum 4 feet horizontally from, and in no
case above or below, unless a 4-foot horizontal
distance is maintained, from electric meters, gas
meters, regulators and relief equipment.
e. Minimum 12 inches from overhang or corner.
3. Use wall thimble when passing through
combustible outside wall (thimble use optional for
noncombustible wall). Insert thimble through wall
from outside. Secure outside flange to wall with
nails or screws, and seal with adhesive material.
Install inside flange to inside wall, secure with nails
or screws, and seal with adhesive material.
4. For noncombustible wall when thimble is not used,
size opening such that bell with locking band
attached cannot pass through.
5. Join vent terminal to vent pipe. Cut vent pipe to
locate vent terminal 3 inches (minimum) and 6
inches (recommended) from wall when joined to
inside vent piping. See Figure 9. Vent terminal
clearance to vinyl wall surfaces is 6 inches.
6. Insert vent pipe through thimble/opening from
outside and join to vent system. Apply sealant
between vent pipe and opening/thimble to provide
weathertight seal.