Model NPR-BI

Pressure Relief Door
Negative Pressure Relief - "Blow-In"

The NPR-BI pressure relief door is designed to open inward to prevent damage to ductwork and excessive negative pressure. The NPR-BI mounts vertically and must be properly secured and sealed to the ductwork by welding or with high pressure sealing cement and screws or rivets.

Standard Construction

Material: 12 ga. (2.8) galvanized steel.

Door Panel: 12 ga. (2.8) galvanized steel.

Hinge: Steel - continuous piano type.

Gasket: 1/4" thick (6.4) compressible sealed neoprene.

Latch: Factory set at desired pressure [3.0 in. wg. to 8.0 in. wg. (0.8 kPa to 2.0 kPa)] - fine-tune adjustable in field.

Springs: Coiled, automatically return door to closed position when pressure is relieved.

Available Sizes:
24" x 10" (610 x 152)
24" x 12" (610 x 203)
18" x 18" (457 x 356)
24" x 24" (610 x 457)