Nitrogen Purging & Testing
Nitrogen purging is in industry standard technique for the replacement of hazardous or undesirable atmosphere with an inert dry atmosphere. The two most common methods of purging are displacement and dilution. The geometry of the process system determines which method is used.
For simple system, displacement purging is usually more effective in terms of time and cost but, for more complex system, dilution purging is used.
Nitrogen can also be used for leak test as a part of facility pre-commissioning services or after facility maintenance where flanges were disturbed, to confirm facility leak tightness. This is done by pressurizing the system with nitrogen gas and identifying leaks by applying soapy solution on tapped flanges after puncturing it. The pressurized nitrogen gas escaping from the punctured tape will indicate if there is leak on the flange.