DIFFERENCE BETWEEN VESSEL AND PRESSURE VESSEL

In industries like manufacturing, oil and gas, and chemical processing, terms like vessel and pressure vessel are commonly used. While they might sound similar, they serve different purposes and have distinct design specifications. Understanding the difference between these two is essential, especially for engineers, operators, and those involved in industrial processes.

What Is a Vessel?

A vessel is a broad term used to describe any container that holds liquids, gases, or other substances. Vessels come in various shapes and sizes, depending on their application. Some common examples include:

• Storage tanks – Used for storing water, chemicals, or petroleum products.

• Boilers – Contain water or steam in heating systems.

• Reactors – Used in chemical processing industries.

Vessels can be open or closed and are not necessarily designed to withstand high pressure. They are usually made of materials like steel, plastic, or fiberglass, depending on the type of substance they contain.

What Is a Pressure Vessel?

A pressure vessel is a specific type of vessel designed to operate at pressures significantly higher than atmospheric pressure. These vessels store or transport gases and liquids under high pressure and must comply with strict safety regulations.

Key Features of Pressure Vessels:

• Designed to handle internal or external pressure – This makes them suitable for applications involving compressed gases, steam, or chemical reactions.

• Made of strong materials – Typically constructed from high-strength steel, stainless steel, or other durable materials to withstand high pressure.

• Requires rigorous testing and certification – Pressure vessels must meet industry standards like ASME (American Society of Mechanical Engineers) or PED (Pressure Equipment Directive) to ensure safety.

Common examples of pressure vessels include:

• Compressed air tanks

• Steam boilers

• LPG (liquefied petroleum gas) storage tanks

• Heat exchangers

Key Differences Between a Vessel and a Pressure Vessel

Aspect	Vessel	Pressure Vessel
Definition	A container for holding liquids or gases.	A container designed to hold gases or liquids at high pressure.
Pressure Handling	Operates at normal or low pressure.	Operates under high pressure.
Material Strength	Can be made of steel, plastic, or fiberglass.	Made of high-strength materials like reinforced steel.
Regulations	May not require strict regulatory approval.	Must comply with safety standards like ASME or PED.
Examples	Storage tanks, boilers, reactors.	Steam boilers, compressed gas cylinders, LPG tanks.

Why Is the Difference Important?

The distinction between vessels and pressure vessels is crucial because of safety concerns. Pressure vessels operate under extreme conditions and require special maintenance, design, and regulatory compliance to prevent accidents like explosions or leaks. Industries must follow safety protocols and use certified pressure vessels to minimize risks.

Conclusion

While both vessels and pressure vessels are used to store or transport fluids and gases, the key difference lies in their ability to withstand pressure. A vessel is a general term for any container, while a pressure vessel is specifically designed for high-pressure applications and must adhere to strict safety standards. Understanding these differences helps in selecting the right equipment for industrial processes and ensuring workplace safety.

**The content of this article is taken from web open source. The blogs are intended only to give technical knowledge to young engineers. Any engineering calculators, technical equations and write ups are only for reference and educational purpose.