CSA 3.19-2008 pdf free download

CSA 3.19-2008 pdf free download.Direct Gas-Fired Process Air leaters.
b. On heaters where the air velocity or pressure drop across the burner can be increased to the point that exceeds that specified by the manufacturer. (See 2.7.2.)
A time delay means not exceeding four minutes may be initiated to retard burner shutdown when the air velocity or pressure drop across the burner is increased above the maximum specified by the manufacturer. If the increased pressure drop still exists after the time delay has expired the equipment shall assume safety shutdown. Power interruption or remote reset is an acceptable means of reset.
c. Where applicable, whenever there is a failure of a separate combustion air fan. (See 1.6.3 and 2.7.4.)
d. Before the air velocity or pressure drop across the burner is reduced to the minimum specified by the manufacturer when the heater is operating in the bake cycle mode provided that this airflow permits compliance with clause 2.10, Burner Operating Characteristics, without the formation of carbon deposits. (See 2.7.5.)
When applicable, these devices shall be connected electrically in series.
The air flow sensing system shall be either non-adjustable; adjustable but factory calibrated and sealed; or adjustable, such that, any setting of the air flow sensing system shall comply with the above. The manufacturer shall specify the setting (including tolerances) of the air flow sensing system that corresponds to the set point(s) which will permit burner operation with the lowest and, if applicable, the highest air velocity or pressure drop across the burner.
1.16.6
Where applicable, a listed high gas pressure safety cut-out switch shall be provided with the limit setting not to exceed 125 percent of the design manifold pressure. The switch should act to shut off the main burner gas in the event of an overpressure condition. Manual reset within the control system shall be required to resume burner operation. Power interruption is not an acceptable method of control reset. (See 1.10.3.)
1.16.7
A heater shall include a fan interlock device which will prevent energizing the gas valve circuit until the fan/motor operation is proven. This device may be a centrifugal switch on the motor or blower, an extra contact of a motor starter where the motor starter is providing overcurrent protection for the motor, or other similar circuit elements which provide equivalent operation.
1.16.8
The burner housing or enclosure and any attached inlet ductwork shall be purged of any explosive vapors before ignition can occur. This purge shall provide a minimum of four air changes through the heater, and, if applicable, all attached inlet ductwork by volume. A purge timer is not necessarily required. (See 1.22.11.)CSA 3.19-2008 pdf free download.