Valves, Gates & Airlocks

Powder valves

Powder valves have an application in varying industries, primarily the pharmaceutical and chemical industries, and are designed to handle solid materials. Powder valves rotate 180 degrees (counter)clockwise to break up and disseminate material through the valve to the next stage of processing. Depending on the application of powder valves, a specific actuator is required that facilitates the rotation. The most common valves used in powder handling applications are butterfly valves, diverter valves, and rotary valves.

Butterfly valves: Butterfly valves regulate flow by starting, slowing, or stopping a fluid. A rotating disk is a mechanism used to regulate the flow by allowing the disk to intermittently close the valve. Butterfly valves are one of the most desirable valve types because of their low cost and lighter weight.

Diverter valves: Diverter valves are employed to convey powder amongst other materials to multiple destinations with care. Diverter valves are often required in dairy, food, and pharmaceutical application and therefore require hygienic standards for safe powder handling.

Rotary valves: Rotary valves find their primary usage in bulk material handling, dust collection, and pneumatic conveying. Rotary valves are used to regulate the flow of material and create consistency to prevent leakage, damage to the valve, and jamming.

Selecting the most efficient valve

Many people think that selecting a valve for dry material handling is a relatively simple process. But in reality, valve manufacturers need more information to accurately select the right valve for the application.

The vast range of valve types available reflects the challenges of controlling and directing the flow of dry bulk solids. Installation criteria determine which valve line is appropriate. The most critical question is “what is the valve intended to do?” After establishing the intended usage of the valve, more concrete attributes of the valve could be evaluated such as the shape and size of the opening, the temperature requirements, and the material of which the valve should be crafted. After this, the material characteristics need to be considered for optimal valve selection.

Going through the process of selecting the right valve could be time-consuming but is always worthwhile as it could prevent future hindrances.

Types of solids valves

There are several basic types of solids valves:

• Ball valves: valves that control the flow of a liquid or gas by means of a hollow, perforated and pivoting ball.
• Butterfly valves (see powder valves)
• Control valves: Control valves are critical in controlling processes by manipulating flowing fluids.
• Diverter valves (see powder valves)
• Flap valves: Valves that allow flow of gases or fluids in one direction while preventing flow in the opposite direction.
• Iris valves: Valves that control the discharge of flowing powders, granules, and pallets.
• Pinch valves: Valves that control the flow of corrosive, abrasive, or granular material. The valve opens and closes by means of pressurized air.
• Knife gate valves: Valves that chop up material to allow this material to freely flow with no interference.