Autoclave Leak Detector

The essential tool for leak fault finding

For technicians who work with Autoclaves in the Medical, Pharmaceutical or Biotechnology industries, they know the importance of a leak-free Autoclave chamber. A failing Bowie Dick cycle usually caused by air intrusion or an "air in chamber" detector alarm must be rectified before any sterilisation cycles can be run. The acceptable leak rate is 1.3 Millibar in 1 minute. It can be difficult and time consuming to find a leak of that size. But a simple method is to check each port in the chamber using the Autoclave Leak Detector tool.

Why use the Autoclave Leak Detector?

The unit is simpler and faster than other existing methods such as helium detectors as no pumping down of the chamber is required and each port is checked in less than a minute. A typical chamber could have 20 to 30 ports so by finding which port is leaking narrows the search to the valve or piping associated with that port. The unit doesn't need a power supply, just a compressed air supply of 90 psi (6 bar). It is ideal when production cycles require minimum downtime as the test can be completed in a few minutes.

How the Autoclave Leak Detector works

The unit works by pulling a vacuum on each port on the inside of the chamber. The vacuum is created using compressed air to drive a Venturi vacuum pump. The suction cup is placed over each orifice in turn and the vacuum is switched on. When the reading on the vacuum gauge reaches 26 inches the switch in the handle is switched to the mid position to hold the vacuum. If there is a leak in this area the gauge's reading will fall. If the gauge holds steady then there is no leak. If no leak is found, then it is safe to assume that the door gasket is the cause of the problem.

Can the Autoclave Leak Detector be adapted to detect leaks with any autoclave?

The tool has an extendable telescopic handle that reaches into the chamber. Different sizes of suction cup can be supplied to suit bigger ports or where probes extend out of a port. Cups can also be custom made to individual requirements. On autoclaves such as Gettinge, Steris, Finn Aqua, Fedegari, Astell, Buxton or CSS, where the ports are easily accessible it is particularly useful. It can also be used on any type of chamber which needs to be leak-free. For example, in chambers used for integrity testing of sealed packs or containers.

The Autoclave Leak Detector as a Preventive Maintenance Tool

The unit can be used as a preventative maintenance tool to warn the operator of the presence of a tiny leak which may not be affecting the performance of the chamber but will eventually become big enough to cause leak test failure. It can find tiny leaks because the test area enclosed in the suction cup of the tool is so small in relation to the size of the chamber. Compare the size of a chamber of 1 cubic metre volume to the size of the area being tested with the suction cup which is about 0.25 litre, the ratio is 4000 to 1. In other words the leak is magnified when using the tool. Normally leaks don’t become apparent until there is a 1 Millibar per minute leak but with the test unit something as small as .01 mbar is easily detectable and can be seen on the vacuum gauge of the Autoclave Leak Detector. This can be understood easier when using the unit. The current acceptable leak threshold is 1.3 Millibar per minute but routine use of the Autoclave Leak Detector would find tiny leaks so the repairs could be planned and carried out at a suitable time without affecting production cycles. A planned leak test using the unit could be carried out on a weekly or fortnightly basis .The test can be performed on all orifices (with the exception of the door gasket(s) in a short time of 30 minutes on a cold chamber. This could save on unnecessary servicing as valve seats are usually changed out on a regular time schedule. Often the valve seats are perfect and do not need to be changed at that time but there usually no way of knowing. But by using the Autoclave Leak Detector to check for leaks one can tell which valve seats need to be replaced (predictive maintenance). This saves time and money. This method of leak testing is the one that resembles exactly the same condition as a programmed leak test because a vacuum is being pulled on each port as in a chamber leak test. But instead of testing the whole chamber at once, each orifice is done in turn so it is a methodical search for the leak. Other methods such as pressurising the chamber or sniffing for helium do not resemble it as closely. If a leak is present under vacuum it may not show up under pressure as the leak might be sealed.

Please contact Tom Gallagher with any queries you may have.