Effective team sterilization is essential for reliable, valid research and lab safety. As such, all labs should periodically leak test autoclaves to ensure that their machine is effectively creating and maintaining a vacuum in the chamber.

Running leak tests verifies the integrity of components such as pipes, seals, and gaskets. These all must be in good repair to create the vacuum needed to reliably process many load types. A leak test failure is better discovered as soon as possible, to prevent unsafe conditions and unreliable research data.

Making It Easy to Leak Test Autoclaves

In case it can’t go without saying, an autoclave leak test can only be performed on machines that include a vacuum option. Any Priorclave autoclave can come with a fully automated vacuum pump, to help eliminate air pockets in complex loads and speed cooling and drying. Vacuum-equipped Priorclaves include our Leak Test Cycle program, which automatically checks the integrity of the chamber and interconnecting pipe-work.

During a Leak Test Cycle, the autoclave evacuates the chamber to your established vacuum set-point, then holds for five minutes before checking the pressure again. After another 10 minutes, the pressure is checked a final time, and pressure readings are then compared. Any increase is the result of air leaking into the chamber. If that relative pressure increase exceeds your established allowance, the system logs a leak test failure.

What Does a Leak Test Failure Mean?

A leak test failure is serious, but not catastrophic—this does not signal any danger of a complete door failure. A leak test failure indicates degradation of some component (e.g., pipes or gaskets), and is an alert that the autoclave is not functioning properly. Discovering a leak test failure early is the most important and valuable reason to leak test autoclaves regularly. Comparing leak test failure data against other previously collected data can give the user insight as to the rate at which components are failing. You can then use that information to decide whether you need to adjust your maintenance schedules or retrain technicians to decrease equipment wear and tear. A leak test failure often means you should schedule a service call as soon as possible.

Bowie-Dick Testing

The Bowie-Dick test (also known as a “dynamic air removal test”) is an essential companion to a leak test. Bowie-Dick tests confirm that your sterilizer can both create and maintain a vacuum, and force steam to fully permeate loads. Steam permeation is essential for labs that regularly handle biohazardous waste—it is notoriously challenging to fully steam penetrate biohazardous and similar waste loads.

To run a Bowie-Dick test, a test pack containing a chemical indicator is run through a sterilization cycle. If the steam is properly penetrating the pack, the indicator will uniformly change color. If the color change is variable, it means the autoclave is not producing sufficient steam pressure to fully permeate materials, and that the temperature is not consistent in the chamber.

How Often Should Labs Run Leak and Bowie-Dick Tests?

The workload of labs varies widely. Some labs run just a few cycles per day or week. Others process a vast volume of material daily. Many larger organizations have set testing guidance to meet specific standards and are determined by their own maintenance and quality assurance departments.

Scheduling autoclave leak tests and Bowie-Dick tests are at the discretion of the organization, with input from their technicians and after considering the types of loads being processed and how high their throughput is. In most labs, vacuum leak testing and Bowie-Dick tests should be a regular part of the maintenance schedule, to discover any potential problems sooner rather than later.

Maintain Safe, Reliable Equipment With the Support of an Industry Leader

Priorclave North America is proud to support the research programs of scientists and investigators throughout the Western Hemisphere. We offer autoclaves with standard test programming for efficient and time-saving maintenance. More importantly, we stand by our equipment with industry-leading perks, including free lifetime technical support, and a low-energy/low-water easy-maintenance design optimized to minimize lifetime operating costs. Reach out to us to discuss your research needs, and begin designing your custom autoclave today!