Being novices in the blog department, we will get to adding our Coolvac Facebook page to the site but in the meantime the following comments are an accumulation of 40 years in the industry. Hopefully passing on these comments will assist all kinds of refrigeration engineers irrespective of their experience to borrow from our time [...]
Overpressure Methods The equipment to be tested is pressurized with a gas, search gas, or a search gas mixture. Between the two methods there exist many variations depending on the particular application. Pressure Drop Method. The test object is filled with a gas (for example air or nitrogen) until the testing pressure is reached. Precision [...]
By applying soap solutions or similar, (typically sprayed or painted on) leaks can be located by watching bubbles forming in the leak area.
An ultra-violet dye circulating with a system liquid permeates through the leak and is able to be detected using an ultra-violet light.
The test object is filled with the search gas or the search gas/air/nitrogen mixture to which the leak detector is sensitive. The leak detector is equipped with a sniffer probe, whereby there is a low pressure at the probe tip. If the sniffer tip passes suspicious points on the test object the search gas coming [...]
Hand held leak detectors using the detection of pressure escaping through the leak source by listening for gas leaking. These leak detectors are very efficient but are limited by the need for absolute quiet during the detection procedure.
Evacuate the system using a vacuum pump. A vacuum pump cannot achieve a vacuum better than the Saturated Vapour Pressure of any moisture (water) or other contaminants that may be in the system or vacuum pump. This is because water or other contaminants that may have been drawn into the pump evaporates from the oil [...]
System must be evacuated to less than 1.0 Millibar absolute. After the system has been evacuated the vacuum pump should be isolated from the system. As a guide, with constant ambient conditions, the vacuum should not rise more than 0.13 Millibar in one hour. A greater rate of rise may indicate a leak or the [...]
A helium leak detector permits the localization of leaks and the quantitative determination of the leak rate, i.e. the gas flow through the leak. Such a leak detector is therefore a helium flow meter. In practice the leak detector performs this task by firstly evacuating the part which is to be tested, so that gas [...]