What Does Pressure Vessel Mean?
A pressure vessel is an enclosed storage container that holds liquids, gases, or vapors at pressures greater than 15 pounds per square inch (PSI), independent of the ambient pressure.
Due to the hazards associated with stored energy, pressure vessels are fabricated under strict regulations and must be operated within designated temperature and pressure limits.
Safeopedia Explains Pressure Vessel
Pressure vessels should not be confused with pressure tanks. While they share a similar function, pressure tanks have a maximum allowable operating pressure (MAOP) of 15 PSI, while pressure vessels start at 15 PSI and can hold up to 3,000 PSI.
Types of Pressure Vessels
Pressure vessels come in a variety of sizes and geometrical shapes.
The most common types of pressure vessels are:
- Storage vessels for products like liquefied petroleum gas (LPG), propane, butane, ammonia, and chlorine.
- Process vessels used in processing industries like paint and drug manufacturing, food processing, and refineries. Specialized process vessels include distillation columns, decanters, industrial mixers, and chemical reactors.
- Heat exchangers that transfer heat between two or more fluids without allowing the fluids to come in direct contact each other.
- Boilers transfer heat using fuel, electricity, or nuclear power as their heat source. Boilers can also transform liquids to vapors in order to generate heat or power.
Hazards Associated with Pressure Vessels
There are many dangers associated with pressure vessels, especially those that are hidden away from sight. The high levels of pressure in these vessels poses a risk of explosion. Damage to the vessel can also result in leakage of hazardous materials.
To prevent failures, pressure vessels must be monitored closely, operated correctly, and tested and maintained regularly.
With the increase of automation, human monitoring of pressure vessels has reduced greatly. However, automated monitoring is far from perfect and risks remain. To prevent incidents, qualified personnel should routinely monitor every pressure vessel's operations.
Pressure vessels must be fabricated in accordance with strict regulations with standards, such as the American Society of Mechanical Engineers (ASME) Section VIII and the American Petroleum Institute (API) 510.