Camfil Air Pollution Control introduced the Stinger, an explosion isolation valve that isolates dust collector explosions to prevent a deflagration from traveling back through the inlet pipe of the dust collector into the workspace. Camfil APC reports that the Stinger is the first U.S.-made explosion flap valve to be certified by an independent testing agency to comply with NFPA standards. It may be retrofitted onto most dust collection systems and used with new or existing Farr Gold Series dust collectors where the risk of a combustible dust explosion exists.
The Stinger valve features a lightweight, composite blade that reacts with high speed in the event of an explosion. It closes faster than heavier steel blades typically used for dust collector inlet protection, according to the company. Because of its light weight, less pressure drop is needed to hold the blade open during normal flow. The composite material has a smooth surface and does not use stiffeners, which can allow dust to build up on the blade.
During normal operation, the airflow holds the blade open. If a deflagration occurs in the dust collector, a pressure wave will travel through the pipe faster than the flame front and close the flap valve, protecting downstream personnel and equipment from injury and damage, according to the company. When the valve is fully closed, a latching mechanism keeps it shut. The closed valve prevents the transmission of flame and keeps smoke, dust and burning debris from traveling through the inlet pipe into the factory. The blade is replaceable, eliminating the need to replace the entire valve after an explosion event. A wear-resistant liner functions as a wear indicator to show when the blade needs to be replaced.
