The hazards of UNSAFE pressure testing

A topic we have discussed many times here and if you have ever attended one of my process safety courses or presentations you have most certainly heard my dissertation on the criticality of pressure testing and leak testing and the fact that these safety-critical functions come with some serious risks, especially if the pressure testing is done pneumatically!  Case in point…

Here are two classic examples of how badly things can go during pressure testing vessels and piping when it is done incorrectly/unsafe:

Storage Tank Failure

At 4:30 p.m. on December 18, 2019, an employee was air testing an atmospheric steel storage tank and was monitoring the internal air pressure of the tank while two coworkers checked for air leaks. The employee was struck by the deck when his coworkers over-pressurized the tank and he was killed from blunt force trauma injuries.

On or about December 18, 2019, and at times prior thereto, employees were exposed to struck-by hazards while performing atmospheric tank internal pressure testing, WITHOUT the use of proper air pressure gauges and pressure relief devices.

Piping Failure

On January 8, 2003, Employee #1 was working in close proximity (about 10 feet) to a pipe undergoing a pressure test. The pipe was filled with nitrogen and measured approximately 25 feet in length and had a diameter of 12 inches. During the pressure test, the pipe reached a pressure of 1550 psi. For some reason, the pipe exploded. Employee #1 was hospitalized and pronounced dead due to injuries sustained in the explosion.

On 1/8/03, at the Duke Energy Waha Gas Plant facility, an employee was fatally injured when a pipe being pressure tested with nitrogen ruptured, striking the employee. The pipe was pressure rated for 815 pounds per square inch and was pressurized to approximately 1500 pounds per square inch when it ruptured.

Consensus engineering standards require that the test pressure when using gas as a medium, not exceed the minimum specified yield strength or 110 percent of the design strength for the material being tested. Employees were exposed to an explosion hazard while checking for leaks during this pressurization process which exceeded the minimum yield strength for the pipe which exploded. One feasible method of abatement, among others, would be to use the guidelines prescribed by the American Petroleum Industry (API) Standard 570, American National Standard Institute (ANSI) Standard B31.3, and ANSI Standard B31.8 which all relate to inspection and testing of pressure piping in petroleum and in gas transmission processes. Abatement Certification and Documentation is required for this item.