Bubble-tight damper designed for isolation applications. Bubble-tight means the damper has the lowest possible leakage rating: zero. The silicone blade seal and double-gland axle seals provide bubble-tight performance. Standard bubble-tight damper includes a manual handwheel actuator. There are many options when considering electric or pneumatic actuators. Some include solenoid valves and switches. Contact factory for assistance. Typical applications: Isolate filters and contaminated components in bag-in/bag-out systems.