Weil-McLain Ultra Manual page 46

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gas fired water boiler
Vertical vent/air termination:
Allowable vent/air pipe materials
1. Use only the materials listed in
2. Purchase bird screens for vent and air terminations separately. See
the parts list at the end of this manual.
Maximum piping length
1. Locate the terminations such that the total air piping and vent pip-
ing from the boiler to the termination will not exceed the maximum
length given in Figure 62.
2. Maximum lengths listed in
elbows required a reduction in maximum length as explained in
the table notes.
Connecting from termination to boiler
1. Install the termination penetrations as instructed in the follow-
ing. Then proceed to page 48 to complete the piping between the
termination and the boiler.
Determine location
1. Locate the vent/air terminations using the following guidelines:
2. The air piping must terminate in a down-turned 180-degree return
bend as shown in Figure 63. Locate the air inlet pipe no further
than 2 feet from the center of the vent pipe. This placement avoids
recirculation of flue products into the combustion air stream.
3. The vent piping must terminate in an up-turned coupling as shown
in Figure 63. The top of the coupling must be at least 1 foot above
the air intake. The air inlet pipe and vent pipe can be located in
any desired position on the roof, but must always be no further
than 2 feet apart and with the vent termination at least 1 foot
above the air intake.
4. You must consider the surroundings when terminating the vent
and air:
a. Position the vent termination where vapors will not damage
nearby shrubs, plants or air conditioning equipment or be
objectionable.
b. The flue products will form a noticeable plume as they con-
dense in cold air. Avoid areas where the plume could obstruct
window views.
c. Prevailing winds could cause freezing of condensate and water/
ice buildup where flue products impinge on building surfaces
or plants.
d. Avoid possibility of accidental contact of flue products with
people or pets.
e. Do not locate the terminations where wind eddies could affect
performance or cause recirculation, such as inside building
corners, near adjacent buildings or surfaces, window wells,
stairwells, alcoves, courtyards or other recessed areas.
f. Do not terminate above any door or window. Condensate can
freeze, causing ice formations.
g. Locate or guard vent to prevent condensate damage to exterior
finishes.
46
— Boiler Manual
Figure 32, page 31.
Figure 62 allow for 1 elbow. Additional
Separate pipes
Figure 62
Maximum piping lengths for separate vent
and air pipe vertical termination
Boiler Maximum
Ultra– Piping, 2" * Piping, 3" *
Feet Elbows Feet
80 30 1 100
105 30 1 100
155 Not allowed 100
230 Not allowed
310 Not allowed Not allowed
* Install reducers as necessary where connecting to the boiler
vent and air connections.
For piping using more than 1 elbow, reduce maximum allow-
able length:
• 7 feet for each additional 4-inch elbow (90° or 45°)
• 7 feet for each additional 3-inch long radius elbow
• 16 feet for each 3-inch short radius elbow
• 7 feet for each 3-inch 45-degree elbow.
• 14 feet for the air termination return bend
Figure 63
Vertical termination — separate pipes
Maximum Maximum
Piping, 4" *
Elbows Feet Elbows
1
Not
1
allowed
1
30 1 100 1
100 1
Part number 550-100-066/0608