NFPA-496 Compliant Stand Alone Purge & Pressurization Equipment It is important to maintain an atmosphere inside a building that is conducive to allowing equipment to operate effectively. Specific Systems InPac PPUs are designed and manufactured to provide those necessary interior conditions. Engineered and proven to stand up to the rigors and harsh conditions of corrosive and hazardous environments. Built to demanding industrial specifications Features corrosion resistant coatings and dual-redundancy for efficiency and to avoid downtime. When combined with a stack package, can reduce the hazardous (classified) area rating within the room from Class I, Div. 1 or 2 to non-hazardous (classified). Available in configurations up to 12000 cfm Controls to automatically purge and pressurize the building. InPac pressurization units are custom-engineered and built-to-order for each customer using a time-proven assembly method. Manufactured using 16-gauge galvanized steel with all-welded construction

Corrosion-fighting 4 mil powdercoat finish Industrial grade motor and direct drive blowers Wired for high level, low level, and fail using Form C contacts, allowing remote notification of alarms Auxiliary (stand-by) fans to serve secondarily as a redundant fan should a failure occur to the primary fan. Pressurization units can be manufactured to seal off the area from outside air via a damper in the event of gas detectionwall ac units 5000 btu Stainless steel and aluminum cabinetmounting an ac unit sideways Gas detection and alarmsr22 ac units for sale Explosion proof design up to Class I Div 1 At Specific Systems, we manufacture HVAC specifically designed for the modular building industry. Our industrial systems can be used on any of the building/enclosure types below, and fit just as well on static structures as they do on modular buildings.

An air purge system is used to flush electrical control equipment with clean air before it is turned on. This ensures that the functionality of the equipment is not affected or damaged by the contaminants from the surrounding environment. Air purge systems are employed for control and analytic technology that is exposed to flue gas resulting from an industrial process. Purging units are central because they maintain a clear boundary path and also ensure that the optical system of the instrument remains clean during prolonged operation. Some systems advanced processes serve to prevent corrosion of other system components by flue gas. Air drawn through the system must be clean, dry and oil free in order to protect the delicate optical equipment including mirrors and lenses. It is crucial that the design of the system ensures that the flow of air does not draw in any contaminants from outside sources. In a faultily designed system, dirt can be brought into the control area rather than drawn out as a result of the complexity of airflow components.

Although negative pressure might seem to draw an adequate amount of air through the affected area to prevent a buildup of dust and fumes, fluctuations in process conditions, operation anomalies, and environmental conditions when the plant is not operational can all lead to contamination and/or damage to instruments. These changing factors make purge air protection a vital element. Blowers provide clean air to prevent contamination of electrical and optical surfaces from dirt, corrosive gases and overheating. Mains electricity is responsible for powering the blower’s motor. Different power ratings ensure that the required air flow is provided under different application conditions, duct pressures and hose lengths. Air flow from the blower depends on the type of fan and the mains supply voltage and frequency. Most air purge systems consist of a fan with a motor, some type of filter housing, and a filter cartridge, all stored in a weatherproof environment. Sometimes, pressure switches are employed to designate deficient pressure to ensure that the required flow is maintained.

Pressure switches are also used to indicate blower failure. The differential pressure trip is connected to the inlet and the outlet of the main filter of the air blower. Failure is indicated by a decrease in the differential pressure. The low pressure trip connects to the main filter outlet. If the pressure drops below a pre-set level, the trip relay operates. These two pressure trips act to indicate three statuses: An air purge heating unit is used to ensure that the purge air remains at a temperature above the acid dew-point. This temperature is typically around 20 °C/68 °F.[2] If temperatures are below this point, the controls will be corroded by condensation of compounds in the flue gas. Heated air ensures that controls are dry during startup. The pressure drop in the length of air hose connecting the blower to the instrument is important when determining blow output requirements. Some systems have one blower unit providing air to two electronic instruments. In order to maintain equality in pressure, the hose lengths must be equal.

At the air inlet, air temperature must be lower than the upper ambient rating of the fan (typically 50 °C/122 °F). The position of air intake is at a point where the least amount of dust, oil, and moisture collects. Fail safe shutters protect the instrument if the purge air supply fails. These are key in systems where flue gas is under positive pressure and, therefore, is very corrosive. If the purge air fails, shutters allow the instrument to function for a few days without causing harm. An air mover systems serve the same purpose as blower systems at a lower cost. However, this type of system can only be used when there is little or no back pressure because they generate lower pressure and airflow. Air mover functionality is based on the Venturi effect. A small amount of high velocity air connected to the side of the casting passes out through a nozzle, creating venturi action. This effect causes a large volume of low velocity air to flow through the venturi and out of the air diffuser.