Service manual

SC Series Boilers – Installation and Service Manual
9
Gas service meters:
The vent terminal requires a clearance of 3 feet (0.9 m) and the air intake a
clearance of 10 feet (3.0 m) from any gas service regulator vent outlet. Vents are prohibited above the
gas meter assembly (not propane regulator vents) within 3 feet horizontally of the vertical center line of
the regulator to a vertical distance of 15 feet (4.6 m).
The bottom of the vent terminal and the air intake shall be located at least 12 inches above grade plus
height of the normal snow line.
Maintain a minimum clearance of 4 feet (1.2 m) below, 4 feet (1.2 m) horizontally from, or 1 foot (300 mm)
above any door, window, or gravity air inlet into any building.
A 4 feet (1.2 m) horizontal clearance should be maintained from electric meters, gas meters, regulators
and relief equipment and in no case above or below, unless a 4’ horizontal distance is maintained.
The terminal shall not be less than 7 feet above grade where located adjacent to a public walkway and
shall not terminate over public walkways or over an area where condensate or vapor could create a
nuisance of hazard or could be detrimental to the operation of regulators, relief valves, or other
equipment.
Equivalent Vent/Air Intake Pipe Length and Diameter
In order for the boiler to operate properly, the venting system, including air intake piping (if used), exhaust
vent piping and terminations, must not be excessively restrictive. Use Table 1 to find exhaust vent and air
intake pipe maximum and minimum equivalent length for a specified boiler model. The installation must
be designed so that exhaust vent equivalent length is within the Max. and Min. range of “Exhaust Vent
Equivalent Length”. Similarly, Air Intake Pipe must be within the Max. and Min. range of “Air Intake Pipe
Equivalent Length”. Use the notes in Table 1 to calculate the equivalent length in feet for exhaust vent
and air intake pipe.
Table 1. Equivalent Length of Venting System
Exhaust Vent
Equivalent Length in Feet
Air Intake Pipe
Equivalent Length in Feet
3 inch diameter 4 inch diameter 3 inch diameter 4 inch diameter
MODEL
Min. Max. Min. Max. Min. Max. Min. Max.
SC-35 8 40 0 45
SC-70 8 40 0 45
SC-105 8 40 0 45
SC-140 8 40 0 45
SC-175 8 40 0 45
SC-210 8 40 0 45
SC-245 8 40 0 45
SC-280 8 40 0 45
NOTES:
1. Calculate the Equivalent Length by measuring the total centerline length in feet and
adding 6 feet for each 90-degree elbow used and adding 3 feet for each 45-degree
elbow used. The calculated Equivalent Length must be within the Max. and Min. limits
for the specified boiler model.
2. The air inlet and exhaust vent must remain 3 inch diameter for SC-35 to SC-140, and
4 inch diameter for SC-175 to SC-280.