Class A Solvent Venting Truck-In oven with explosion relief latches
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Solvent Venting Ovens

All standard Gruenberg ovens can be designed to house volatile atmospheres. Gruenberg designs all Class A ovens to conform to OSHA, NFPA 86A, Factory Mutual (FM), and Factory Insurance Association (FIA) requirements.

As part of the safety design, Class A ovens must be equipped witha high exhaust rate: since the heating elements are an ignition source, a high exhaust rate is needed to dilute the volatile vapors below the "lower explosive limits." As a result, the heating elements’ KW must be sufficiently increased to compensate for the heat loss caused by the above-normal exhaust rate. In addition, for a Class A oven to be energy efficient, the additional KW required must be carefully calculated according to solvent load and operating temperature requirements.

• Explosion venting: pressure relief latches or separate caged or hinged explosion relief panels
• A separate power exhauster sized according to solvent load and operating temperature
• Heating systems interlocked by differential switches with both the exhaust and circulation systems so that loss of airflow automatically shuts down the heat
• A purge timer to effect a minimum of four complete changes of the oven air volume before the heater is energized
• A fail safe, separate, manual reset, High Limit thermostat to shut down the heat if there is a primary control failure
• Electric ovens require a second heater contactor to be associated with the High Limit thermostat on electric ovens
• A door switch to shut down power to the heater and circulation fan/blower if the oven door is open during operation
• Markings on the oven including various warning labels and a capacity curve showing maximum solvent load at a given temperature.
• Gas ovens must have an automatic electric ingnition with pilot flame supervision by an electronic device; a main gas safety valve; high and low gas pressure switches; and a differential switch should a mixer be used