What is a stainless steel pressure vessel?

A stainless steel pressure vessel is a type of container designed to hold its contents at pressures above 15 psig (that’s 15 pounds of force applied per square inch, relative to atmospheric pressure). Pressure vessels withstand high pressures, applied externally or internally, with a large factor of safety. It’s important to understand the basics if you’re going to use one since operating them under conditions they aren’t designed for can cause some serious damage. 

Why make pressure vessels out of stainless steel? 

Stainless steel is a strong material that is nonreactive with most gases and liquids – so the contents stored in the container won’t degrade the material making up the walls. This metal is tough enough to stand up to very high pressures, but soft enough that it won’t fracture or crack under standard conditions. Compared to more exotic metals, it’s easy to machine so manufacturing parts from it requires less effort, fewer specialized workers and equipment, and it’s more economically priced and available. 

What do people use stainless steel pressure vessels for? 

Pressure vessels usually hold gases and liquids that need to be at a higher pressure than the atmosphere. You’ve probably used some small carbon steel ones before if you’ve ever cranked up the gas on a grill or used a portable camping stove or used an air compressor at home or work.   

With this connection, consider that there are also more technical and custom designs that use stainless steel vessels.  These industry and applications include: 

• Aerospace research and technology development 
• Thermal vacuum chambers for spacecraft testing and verification 
• Thermal management for infrared and x-ray detectors in space 
• Storage and transportation of cryogens like liquid nitrogen and liquid helium

How do I use pressure vessels safely? 

It’s important to treat pressure vessels with care, no matter what you’re using them for. This includes inspecting them regularly for dents, dings, rust spots, and any other signs that the structure might be damaged. You also have to choose the right pressure vessel for your design, keeping in mind what pressures and environmental conditions it’s going to be exposed to.  Cyclic loading considerations for some applications is especially critical as well.  

Rexarc specializes in custom stainless steel pressure vessels and would be happy to answer questions you have about them! Reach out to us here, or read more about them here.