In many cases pressurization allows the use of general purpose, or unclassified, equipment in an otherwise hazardous (classified) location. Designed in accordance with the National Fire Protection Association, NFPA 496, Marc’s pressurization units, (also called pressurizing units and room pressurizers) provide a minimum of 0.1" W.C. positive pressure to a closed room and 60 fpm minimum purge through open doors and louvers.

The room pressure setting is adjustable at the controls section in the front of the pressurizer.  When a door opens, the blower speeds up to provide the additional air necessary to provide a minimum of 60 feet per minute purge through the door opening.  After the door closes the blower slows down to the selected setting to maintain the desired room pressure.

CSA (C/US) Certified - Our pressurization units are CSA (C/US) Certified for Class I, Division 2, Groups B, C, D hazardous (classified) locations in both the single and dual blower models for Type Z pressurization.

These powerful pressurization units incorporate direct drive, backward-inclined blower wheels made of non-sparking aluminum.  The blower motor is totally enclosed, severe and marine duty, inverter-duty, and CSA certified for Class I, Division 2 locations.

The PVDX dual blower series pressurization unit incorporates a primary and a standby blower.  In the unlikely event of the failure of the primary blower, the standby blower energizes to replace the primary blower and locks it out of the circuit.  The standby blower will now maintain the desired pressure inside the closed room and provide the 60 fpm purge through all openings.

Explosion proof pressurization units are also available for Types Y and X pressurization.  All of our pressurization units and pressurizing systems are designed for a black start.

The pressurization unit can be supplied with a remote control panel in lieu of the built in pull out controls drawer when required.

Fresh air stacks can be furnished in a guy-wire or free-standing style and includes a rain cap with bird screen. Free-standing stacks can be furnished in either a welded pipe design or in a lighter weight, heavy gauge spiral pipe design. Our free-standing stacks are made in 10 foot long (max.) sections and with heavy, seal-welded flanges at both ends. The free-standing stacks are P.E. Certified for:

• 125 MPH winds - Free-standing spiral pipe design, 27 foot tall.
• 150 MPH winds - Free-standing welded pipe design, 27 foot tall.

Free-standing stacks must be properly secured at the base with anchor bolts in a concrete foundation or seal-welded to a structural steel support.

Click on the photo to view a larger image.