EnviTec’s EVTBD blast dampers are designed for protection against sudden blasts and instantaneous pressure changes. They can be square, rectangular or round and can be flange mounted and constructed from various materials. The EnviTec blast damper was designed using the RISA 3D structural program with a rod strength of 36,000 psi and a maximum deflection ratio of L/180. The EVTBD-G model includes a high frequency equalizing grid and debris screen.

EnviTec manufactures heavy duty industrial grade dampers and shuf-off valves for isolation and/or control of process air and gases. EnviTec specializes in custom designs for unusual or severe duty applications. Our standard designs are suitable for temperatures of 800° F (427°C). Optional features for operating temperature to 1600° F (871° C) are also available.

EnviTec Damper and Shut-Off Valves

Blast Containment EVTBD Damper Series:

Manufactured in square, rectangular and round configurations and in a variety of materials. These dampers are used in the following applications:
  • Chemical, paint or hazardous material storage rooms
  • Refineries, petrochemical and chemical plants
  • Oil & Gas facilities
  • Research facilities dealing with explosive materials
  • Engine test cells
  • Ammunition depots

Louver Damper Series:

EnviTec’s heavy duty industrial grade louver dampers are available with parallel or opposed action linkage for isolation and/or control of process air and gases.

Butterfly Damper Series:

Heavy duty industrial grade butterfly dampers are custom designed for use in high temperature and pressure applications.

Slide Gate (Guillotine) Shut-Off Valve Series:

EnviTec custom designs guillotine and slide gate dampers to suit any application. Our rugged, heavy duty designs are available in sizes from 4 to 96 inches (100 to 2500 mm), round, square or rectangular and are suitable for temperatures up to 1000°F (538°C).

Diverter Valves and Damper Series:

If your application requires process air or gas diversion, consider the advantages of an EnviTec completely preassembled diverter assembly. The use of one actuator with a slave linkage saves cost and assures simultaneous operation of both dampers in the tee assembly. Spring assisted actuators can be used to provide a predetermined fail position of the damper vanes. Proof of open/closed auxiliary limit switches can also be provided.


  • Custom Designed for Application
  • Various Materials of Construction, including Galvanized, Carbon, Hardened or Stainless Steel
  • Various Coatings Available
  • Optional Seals for 99% + Shut-Off
  • Weather Hoods and Inlet Screens
  • Limit Switches and Position Indicators
  • Heat Shields
  • Manual and Automatic Actuators and Controls
  • High Temperature, Corrosion Resistant and Abrasion Resistant Construction
  • Optional Castable Refractory Linings, Heat Shields, Position Indicating Switches, Slave Linkages.
  • Formed Channel, Structural Channel or Structural Angle Frames
  • Round, Square or Rectangular Configurations in Various Sizes