Now thanks to Holtec’s pioneering work, the cost and operational downtime associated with replacing corroded sprinkler piping can be avoided. With ongoing innovations in this field, we are at the frontlines of the rapidly growing application of using nitrogen gas in dry and pre-action sprinkler systems – virtually eliminating corrosion in new piping systems and allowing the use of less costly materials during construction. Generated nitrogen gas is the effective and environmentally friendly way of treating this costly problem, and available leasing allows for rapid implementation of the technology.



Holtec supplied the first nitrogen generator in the US for protecting 13 pre-action systems in a data center in NC. In 2006. 99% nitrogen (with 1% oxygen) was the basis in that system. The following year dry and pre-action sprinkler systems in two more data center were provided similar protection. All of the above referenced systems have and operated without corrosion problems since that time.

From 2008 until 2013 dry 98% nitrogen (with 2% oxygen) was used as the medium for corrosion protection. This was applied in conjunction with a procedure of first pressurizing the sprinkler piping with air to meet the required 30 minute fill time. The air was then purged out and replaced by nitrogen over a set period of time by vent assemblies (multiple types offered with varying degrees of automation), one installed on each zone.

In mid-2013, Holtec made the decision to return to the use of nitrogen with 99% oxygen to further enhance the protection afforded at minimal additional cost.

Our most recent innovation has been to recognize that by producing 99.5% nitrogen (with only 0.5% residual oxygen), the need for venting of the initial air fill is made redundant when compared to competitors generators that produce nitrogen with 2% oxygen (4 times higher). Eliminating the justification for using vents saves a great deal up-front capital cost and eliminates potential long-term maintenance cost and other potential issues. For a copy of the paper that details the basis of this innovation, please contact Holtec.



The oxygen content of moist compressed air is by far the main cause of internal corrosion in steel and galvanized steel forming gas pressurized sprinkler piping. Microbial Induced Corrosion (MIC) is relatively of minor importance.



Install Holtec nitrogen generator(s) to pressurize the dry or pre-action sprinkler piping with 99.5% nitrogen.


  • Eliminates damage caused by leakage onto critical facilities and equipment
  • Eliminates costly disruptions and downtime by extending the useful life of sprinkler systems about at least 10 fold
  • Saves at least 30% of piping costs in new construction by allowing the use of thin-walled black steel piping instead of galvanized steel
  • High Nitrogen purity eliminates the need to install and maintain costly venting devices to purge the initial charge of air out of the sprinkler piping
  • The option of leasing the equipment from Holtec means peace of mind is within easy reach
  • Eliminates the need for costly and unreliable corrosion monitoring devices and services


  • Holtec has a complete range of standard equipment modelsand the technology to serve the huge range in size variation in gas pressurized systems. (See link below)
  • Holtec can utilize Pressure Swing Adsorption (PSA) technology for larger systems which are more efficient (smaller air compressor needed) if desired.
  • Holtec’s corrosion control systems can also be custom designed for any application and our Engineers are happy to consider new or unusual applications.



  • Most of Holtec’s Generators are supplied as a single skid for fast, low cost installation.
  • Holtec utilizes proprietary design tools to quickly specify and size systems for a perfect fit for any application.
  • Leasing the equipment from Holtec provides the fastest way to overcome capital budgeting limitations.



  • Holtec nitrogen generator inerting systems use no chemical additives.

Information needed for a quotation from Holtec:

In order to be able to quickly evaluate the application of nitrogen for gas pressurized sprinkler systems Holtec needs the following initial information. All of this is on our inquiry form but here is a little more explanation why the information is required:

  • How many zones are to be served?
  • What is the approximate volume of each zone (± 10% )?
  • If more than one zone, describe the grouping and approximate separating distances?
    • Answers to all of the above points are necessary to be able to make an initial quote, even if some of the information is not fully accurate.
  • What is the intended operating pressure(s) for the zone(s)?
    • Operating pressure will impact the size of generator required.
  • Is there an existing air compressor used for pressurizing an existing zone?
  • Is there a source of piped “house air” gas already at the site that could be used?
    • The compressor supplied with the generator is typically used for the 30 minute “fast fill” but if an existing source of piped compressed air, or an existing compressor could be used for the initial fill and possibly reduce the size of nitrogen generator needed.
  • Is there an electronic BMS at the site and is there specific information required for transmission to the BMS of fire alarm panel?
    • Data that is available varies with generator model and purging equipment type so it will be necessary to know this, at least prior to ordering equipment.


Safety Notice

Always exercise caution using these systems in occupied areas as nitrogen in the absence of oxygen does not support life. We have created a simple computer calculation method to determine if an occupied space is sufficiently large to be safely protected by a sprinkler system pressurized with nitrogen gas, taking into account the volume in the sprinkler piping, the operating pressure and the elevation at the location. Holtec is making this available to all. Please contact us for your copy of this important tool.