UTICA BOILERS UB90-50 Installation Manual page 23

3.
Combustion air and vent piping connections on boiler
are sized for 2" pipe. Any pipe size change (to 3") must be
made outside of the boiler casing in a vertical run of pipe
to allow for proper drainage of vent condensate. Due to
potential for flue gas temperatures over 155°F, the first five
(5) feet of vent pipe must be CPVC, the remaining vent
pipe can be PVC. If any elbows are employed within the
first 5 feet of vent, they must be CPVC too. Two (2) - 30"
pieces of 2" CPVC pipe are furnished with the boiler.
Material
cPVc
radel - a200
* Allowable temperatures based on Classifications covered in ASTM D4396 [Deflection Temperatures under Load
(264 psi) (1819KPa)].
** Allowable temperatures based on Classifications covered in ASTM D1784 [Deflection Temperatures under Load
(264 psi) (1819KPa)].
*** Allowable temperatures based on Classifications covered in ASTM D3965 [Deflection Temperatures under Load
(264 psi) (1819KPa)].
COMBUSTION AIR AND VENT PIPE
MaxiMUM allowaBle teMPeratUres
oF tyPical NoN-Metallic VeNt Material
HDt
°F
PVc
158
210
aBs 180
414
NOTE: The transition from 2" pipe to 3" pipe must be made
in a vertical run.
rti
°c °F °c
70 – –
100 – –
82 – –
212 – –
23
standard
ASTM F891 *
ASTM D2665 **
ASTM D1785 **
ASTM D2241 **
ASTM D2846 **
ASTM F441 **
ASTM F442 **
ASTM D2661 ***
ASTM F628 ***
UL-1738
ULC S636