How to select vessel for your pharma applications（part Ⅰ）

What are vessels, and what are they used for 

Vessels are round metallic structures containing liquid without affecting their state, properties, and chemical composition. The liquid inside a vessel can be included for storage or processing using specified tools and accessories.

Depending upon the application and process requirements, they can be installed with additional components such as a mixer and heating system.   

In the pharmaceutical industry, vessels are used for various applications, such as 

• Holding liquid products during intermediate manufacturing stages

• Transferring liquid to a filling machine, such as an ampoule filling machine

• Mixing and blending liquid during the liquid dosage manufacturing process

• Filtration of the liquid product or raw material (during or before the manufacturing process

Vessels for pharma applications require specialized metal characteristics, because the pharma drug product comes in direct contact with the vessel, and these metal features are necessary for product safety.  It includes

• Stainless Steel 316L for product contact parts

• Dead points

• Welding requirements.

Additionally, some features are necessary for the successful execution of the manufacturing process, such as 

• Temperature sensors to monitor inside temperature for some applications. Because some products require heat to execute manufacturing successfully

• Pressure sensors monitor the vessel's pressure; some applications require elevated pressure inside the tank.

• A mixer or agitator is used to mix solvent with raw material during the manufacturing process. The material of construction of mixer or agitator must also be compatible with pharma drug requirements, as mentioned above

• Load cells are used to monitor the weighting data of the materials inside. It can be also programmed or modified to monitor the level inside a vessel by using its input through a central controller.

• Level sensors monitor the vessel's level and prevent overflow and accuracy in the attached process. 

Types of Vessels 

The vessel type is defined by the application for which it is being used and developed, including the following. 

Manufacturing vessels 

These vessels are specifically used to manufacture a liquid pharma product. It contains additional accessories, such as 

• Mixer to mix different raw materials and solvents.

• Heating element to achieve high temperatures required by different materials and chemicals

Storage Vessels

These vessels are only used to store liquid between intermediate stages, such as 

• Before filling process

• The results are processed by the quality department and awaiting approval

Pressure Vessels

Some applications require liquid inside the vessel to be stored at high pressure. For these applications, vessels are manufactured to sustain high pressure by re-enforce material strength. Additional accessories are also required to facilitate pressure-related applications, such as 

• Pressure indicator to monitor the pressure inside and to ensure it does not deviate form its working pressure

• Pressure safety device to prevent damage in case pressure abnormally increases without control

• Safety valve to release gas if the pressure increases above the maximum permissible limit 

What can go wrong if not selected appropriately?

The wrong vessel selection disturbs the attached process, which can include the following:

Vessel damage

 Vessels are constructed to perform a specific function, and if processes other than the design are used, it can damage the vessel's entire structure.

The main reason is that the vessel is a large mechanical structure whose strength and tolerance are added according to the product and process. If other than the approved methods & processes are used, they will exceed the tolerance level of the vessel, subsequently damaging the internal structure.

For example, if supply pressure is not applied w.r.to the design pressure, it will damage the vessel. 

Product Damage

An inappropriate vessel selection will affect the relevant pharma process, affecting the product inside. The vessel will lose the ability to perform the specified task related to this process, depriving the product of its required attributes and quality. 

For example, in pressure-related applications, if high pressure-specific vessel is selected for a low pressure product, the high pressure will tear off all the chemical composition of the product inside, depriving the product of its therapeutic effects.

Low productivity

If wrongly selected, it will decrease the vessel's total capacity of the production in a given time, thereby decreasing the total productivity. For this reason, a single batch will consume more time in the vessel. Additionally, in case of problems, the vessel will spend more time in the workshop for maintenance than on the production floor. 

Low productivity also affects the pharmaceutical manufacturer's market, causing the manufacturer financial loss.