Pressure vessels are used around the world for a variety of applications that require holding liquid or gas at a pressure that's considerably higher or lower than the ambient pressure. From simple compressed air machined to nuclear reactor vessels – pressure vessels are relied on in a number of ways. However, in every case – they are relied on to be safe.

When pressure vessels were first introduced to the world during the industrial revolution, their incredible capabilities were offset by the fact that they were also incredibly dangerous. In a single year, 50,000 men and women were killed in pressure vessel accidents, with over 2 million injured. Fortunately, standards and regulations around the world now ensure that pressure vessels are constantly monitored for safe operation.

One of the first inspection techniques used to ensure a safe and effective pressure vessel is online inspection. Online inspection is incredibly important as a first step in ensuring safe pressure vessel operation, for pressure vessels of any size. One of the most common techniques used for online inspection is using an ultrasonic testing device to determine the thickness of the metal. By doing this regularly over time, it is possible to monitor the pressure vessel's thickness in key areas. As soon as the pressure vessel's metal reaches a minimum thickness, action is taken to prevent failure or rupture.

In addition to ultrasonic testing of pressure vessels, a number of other methods are used to ensure safe, long-term operation. This includes frequently checking and maintaining pressure release valves and other pressure components, such as sentinel holes, coupons, fittings, and more.

Another inspection method frequently used for pressure vessels includes hydrostatic testing, which is typically used on pressure vesse4ls such as pipelines, gas cylinders, boilers, and more. Hydrostatic testing tests pressure vessels for strength and leaks by using high pressure water. Sometimes, water is dyed to help technicians more effectively detect leaks. In many cases, the water is pressurized to a very specific test pressure in order to ensure accurate testing for the specific vessel. For instance, if a cylinder is rated to DOT-2015 PSI, then it would be tested for 3360 PSI to ensure a proper margin of error.

Diligent pressure vessel maintenance is not only important for safety. Maintenance can also have a real impact on society at large. For instance, almost every oil refinery relies on pressure vessels. If a pressure vessel used at an oil refinery were to fail due to any sort of problem, chances are that refinery would shut down. The refinery would remain out of commission for days, weeks, or even months to ensure that the pressure vessel in question is operating properly. This would cause a noticeable shortage in supply, which would directly affect the price of gas at the pump, outlining one simple reason why it's in everyone's best interest that pressure vessels remain diligently tested, inspected, and maintained in every industry. Ultrasonic testing is frequently used in these scenarios.

Hydrostatic testing is commonly used on pipes and poplins to expose potentially defective materials that might have missed prior detection while also exposing any possible links and ensuring the overall integrity of the entire system. For instance, buried high pressure oil and gas pipelines around the world are commonly tested for strength by pressurizing them to at least 125% of their standard maximum operating pressure. In the case of both examples, proper testing and maintenance has a real impact on the world at large by ensuring uninterrupted service, especially when it comes to industries that provide products we rely on, like oil.