What is a Rotary Valve?

Take any industry, whether it is a pharmaceutical or chemical or textile or any other industry, valves are integral part of the production process. Valves basically control the flow of solids, liquids or gases. Rotary Valve also known as Rotary Feeder is a very important member of the valve family. It is used to feed bulk solids material at a uniform rate.

Design of rotary valve is very critical for satisfactory performance of the entire manufacturing process. The key design factors include:

·         Location and application

·         Feeding rate required

·         Bulk density and material characteristics

·         Size of the valve

·         Flange type (round or square)

·         Material of construction required 

Rotary Valve / Rotary Feeder

Construction of Rotary Valve

A rotary valve typically consists of valve body, rotary vanes, shaft and drive. It is a type of mechanism that directs the flow of bulk solids through a circulating rotary vane. This is in contrast with the linear valve that moves up and down to control the flow. The drive consist of motor and gearbox arrangement. The Body and vanes can be of cast iron, cast steel or stainless steel construction. The rotary vanes come with Teflon tips for abrasion resistance.

Application of Rotary Valves

Rotary valve has been traditionally used in various applications and today there has been tremendous change in their efficiency because of its new design. It is used below the hopper or silo which stores bulk material. Some of these valves come equipped with the air lock design that lets them to be used in pressurized conditions

Selection of Rotary Valve
Depending on the application, one can choose the rotary valve. Feeding rate of the bulk solid required, bulk density of the material, flow ability and other critical characteristics of the bulk material are the key factors that determine the type of valve to be used. Knowing what type of valve will be useful and that which offers cost effective solution with best efficiency is crucial as wrong selection can lead to numerous problems.