1.8.7 MARKING OF GAS VENTS
In those localities where solid and liquid fuels are
used extensively, gas vents must be plainly and
permanently identified by a label reading:
"This gas vent is for appliances which
burn gas only. Do not connect to
incinerators or solid or liquid fuel burning
appliances."
This label must be attached to the wall or ceiling
at a point near where the gas vent connector
enters the wall, ceiling or chimney.
The authority having jurisdiction must determine
whether their area constitutes such a locality.
1.8.8 VENTING MULTIPLE APPLIANCES ON A COMMON VENT
COMMON GAS VENT
When two or more openings (for vent connectors)
are provided in a chimney or gas vent, the
opening should be at different levels. They should
never be opposite one another.
When two vent connectors enter the same gas
vent or chimney, the smallest of the two should
enter at the highest position possible.
PRESSURIZED VENTS OR VENT
CONNECTORS
DO NOT CONNECT THE FLUE OF AN
APPLIANCE VENTED BY NATURAL DRAFT TO
A VENT SYSTEM WHICH OPERATES UNDER
A POSITIVE PRESSURE.
SOLID FUEL APPLIANCE VENTS
Gas appliances must not be vented to a vent or a
chimney which serves a solid fuel burning
appliance.
1.8.9 VENT AND CHIMNEY TERMINATIONS
HEIGHT ABOVE ROOF OR OBSTACLE
WATER BOILERS AND LOW PRESSURE
STEAM BOILERS: No less than 3 feet above the
roof and no less than 2 feet above any parapet or
obstacle closer than 10 feet from the vent outlet.
HIGH PRESSURE (OVER 15 PSIG) STEAM
BOILERS: No less than 10 feet higher than any
portion of any building within a distance of 25 feet
from the vent.
MINIMUM HEIGHT ABOVE DRAFT CONTROL
Chimneys and gas vents must extend at least 5
feet above the highest connected barometric draft
control or any appliance flue outlet.
CLEARANCE FROM AIR INLETS
The vent or chimney must terminate no less than
3 feet above any forced air inlet within a distance
of 10 feet. It must terminate no less than 1 foot
above, or 4 feet below, or 4 feet horizontally from,
any door, window or gravity air inlet into a
building.
CLEARANCE FROM PUBLIC WALKWAYS
The vent exit of a mechanical draft system must
be at least 7 feet above grade when located next
to public walkways.
PROTECTION OF BUILDING MATERIALS
FROM POSSIBLE CORROSION OR
DISCOLORATION FROM FLUE PRODUCTS
The products of combustion from gas or oil
contain potentially corrosive gases and high
temperatures. For this reason, the chimney or
vent exit must be designed to prevent exposure
of the building materials to the flue products.
Failure to do so may result in deterioration or
discoloration of building materials.
VENT SUPPORT
The gas vent or chimney must be securely
positioned and supported. Guy wires or other
reliable means must be used to prevent
movement of the vent.
Summary of Contents for Forced Draft Steam Boilers
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