• November 28, 2023

Dampers are integral components of various equipment in the pharma industry, mainly used to control fluid flow. This article discusses dampers for pharmaceutical, their control mechanism, and in the end, some practical applications.

Pharmaceutical equipment comprises many components, systems, and parts to perform the desired production process. Dampers for pharmaceutical equipment are also one way to control the fluid flow used in various pharma product stages and applications. They are an integral part of equipment and processes where fluid flow occurs, and it becomes difficult to control if it is not available, is faulty, and not functioning properly.

What are Dampers for pharmaceutical?

Before we discuss Dampers for pharmaceutical, let’s briefly discuss dampers.

What is a damper?

A damper is a mechanical assembly that controls and regulates a system’s fluid flow. It consists of a round, rectangular, or square metallic enclosure. Inside the enclosure are metallic plates of different sizes and shapes arranged in different orientations. These plates close to form an obstruction for a fluid to flow across it. All the plates are attached to a single actuating point for activating these plates simultaneously.

The damper can be controlled manually through the handle or automatically through an actuating mechanism. Personnel open or close the damper whenever required through the handle or a lever for manual operation.

dampers for pharmaceutical can be actuated automatically through damper actuators, or through manual handle
Dampers for pharmaceutical can be actuated automatically through damper actuators, or manual handle


For automatic control, electrical or electronic signals from the main or programmable logic controller control the damper for automatic operation. It requires a damper actuator that converts the incoming electrical or electronic signals from the controller to control the damper.

The damper is installed across the pipe, duct, or conduit where fluid flows. The flat obstruction side faces the fluid flow in a pipe, duct, or conduit.

When the damper is fully closed, it restricts the fluid flow. Similarly, if the damper is open, it allows the fluid to flow.

Operating Mechanism of Dampers for Pharmaceutical

A damper is controlled and operated with damper actuators; dampers are useless in any pharmaceutical process or application without them.

Damper actuators are electromechanical devices that actuate the damper in pharma equipment. They take input as electrical or electronic signals and actuate the mechanical assembly builds inside the damper actuator. The amount of actuation is directly proportional to the amplitude of the input electrical or electrical signal, i.e., the higher the input signal, the higher the mechanical actuation, and vice versa. The damper actuator is installed with the damper in the pharma equipment, and the damper actuator’s mechanical assembly activates the damper’s drive mechanism.

When the damper actuator is activated through an input electrical or electronic signal, it activates the dampers. The damper then moves from its resting or initial position. When the input signal at the damper actuator becomes zero, the damper goes back to its resting or initial position.

In addition to damper actuators, dampers can be actuated or activated manually through a handle or lever.

Methods of activating dampers for pharmaceutical processes and equipment

There are various methods of activating dampers for pharmaceutical equipment, commonly classified as the following

  • On / Off Position
  • Partial On / Off

On / Off Position

In the On / Off position, the damper is either fully activated or not activated, i.e., fully opened or closed. The damper swings between its minimum or maximum position without any intermediate position. These dampers are used in pharma applications where only a fluid flow supply is required or not required. Examples include steam supply to autoclave.

In these damper for pharmaceuticals applications, the damper actuator’s input electrical or electronic signal is either maximum or minimum—for example, 0V or 4mA for the minimum position and 10V or 20mA for the maximum position.

Partial On / Off Position

In the partial On / Off position, the damper also resides in an intermediate position, anywhere between the maximum and minimum positions. These types of Dampers for pharmaceutical are used in applications requiring a controlled fluid flow volume. Examples include compressed air flow in a spray gun or coating pan.

In this application for Dampers for pharmaceuticals, the input signal is between the maximum and minimum values. For example, 2V/6mA, 4v/8mA and 6v/10mA. The value of the input signal depends upon the process requirement.

Types of Dampers for pharmaceutical industry

Let’s discuss some types of dampers in the pharmaceutical industry

Butterfly Damper

Butterfly dampers are fixed round-shaped metallic structures with a metallic disc inside them. The disc is movable and moves perpendicularly to the round-shaped structure. The damper is closed when the metallic disc is parallel to the round-shaped structure. The damper opens when the metallic disc is perpendicular to the round structure, and fluid can freely flow across it.

Butterfly dampers are used for exhaust, air ducting, and ventilation.

Blade Dampers

Blade dampers have thin, small metallic strips called blades aligned in a rectangular structure. All blades are attached to a single actuating mechanism, working collaboratively for damping action.

There are two types of blade damper – Parallel and Opposed.

In parallel type, metallic strips are installed parallel to each other, and when actuated, they all move in the same direction or way. They are used in applications where minimum pressure drop is tolerated during damper activating.

In the opposed type, metallic strips are fixed at a different angle from their neighbor, creating a zig-zag pattern, and the edges of each blade overlap with each other when closed. These dampers are used to modulate airflow. However, they provide poor pressure control during damper activation.

Applications of dampers for pharmaceutical industry

Let’s discuss some common applications of dampers in the pharmaceutical industry

  • Air Supply / Exhaust in Dry Heat Sterilizers
  • Air inlet/outlet supply in fluid dry


Air Supply / Exhaust in Dry Heat Sterilizers

Dry Heat Sterilizers are used to sterilize the items used to manufacture parenteral products. It uses dry heat to achieve sterilization temperature, circulating inside the chamber. The air enters the chamber from one opening, called an inlet, and exits from another, called an outlet.

Dampers are installed at the air inlet and outlet, which opens and closes automatically, per the process requirement, to control the hot airflow inside the chamber.

If dampers malfunction or fail to open at a specific time, hot air will not flow accurately inside the chamber. It can result in uneven temperature distribution and failure to achieve the desired temperature.

Air inlet/outlet supply in the fluid dryer

Fluid Bed Dryer – FBD is the equipment used in the granulation section of a solid oral department. It is used to dry the raw pharma product to remove the moisture content. It uses hot air to dry the material contained in a product container.

Dampers are installed at the inlet and exhaust of airflow to control and regulate the desired airflow volume through the pharma product. The inlet air damper regulates airflow flow inside the product container. It also helps to regulate the product bed temperature.

A damper is also installed at the exhaust to control the exhaust air flowing outside the fluid bed dryer.

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