Weil-McLain WTGO Installation And Start-Up Manual page 35

WTGO
GOLD OIL-FIRED NATURAL DRAFT WATER BOILER — SERIES 3 —
Close clearance installation
Figure 25
Flue pipe clearances
Combustible surface
6"
Protection
Type "L"
double-wall
vent pipe
Table 6
Protection required for clearances
less than 6 inches from double-wall
vent pipe*
Dimension A
(When desired minimum
clearance from
Type "L" double-wall
vent pipe to combustible
surface is:)
½" thick insulation board
3"
over one-inch glass fiber or
24 gauge sheet metal with
2" one-inch ventilated air
½" thick insulation board
3"
with one-inch ventilated air
* All clearances measured from outer surface of
equipment to combustible surface, not to the
protection used.
** Apply to combustible surface unless otherwise
noted. Cover all surfaces as specified in Table and
Figure 25. Thicknesses are minimum.
*** Factory-fabricated board made of non-
combustible materials, normally fibers, having
thermal conductivity in range of one (Btu-inch)/
(hr./sq. ft./°F) or less.
+ Mineral wool batts (blanket or board), having
min. density of 8 lb/ft3 and a min. melting point of
1500°F.
Other dimensions available. Refer to NFPA-31.
Part number 550-141-825/1211
SERVICE TECHNICIAN ONLY — read and follow completely.
A
6"
Use the following
protection**:
***
mineral wool batts+
space
***
space
(continued)
Figure 26
Back vent clearances
24" For servicing
or min. 2" For close
clearances
Combustible
surface
2"
Note: 2" min. on sides
Figure 27
Top vent clearances
A
Combustible
surface
2"
Note: 2" min. on sides
Boiler Manual
A
A
Combustible
surface
A
24" For
servicing
or min. 2"
For close
clearances
2"
Combustible
surface
35