CG9 Glass Bulb PRD

The Most Reliable and High Performance PRD on the Market Today

NorAm’s CG-9 pressure relief device (PRD) - thermal relief device (TRD) is based on reliable glass-bulb technology. The US Department of Transportation (DOT) requires that all high pressure gas storage systems have a PRD/TRD in the event of a fire and the resulting dangerous build- up of pressure that can rupture a cylinder. The traditional option is a CG4 or CG5 PRD which is based on eutectic metal in an orific combines a thermal sensitive eutectic metal and a burst disc.

Typical CG5 PRD'sover time

Traditional CG4/CG5 PRDs present several inherent problems:

  • CG4/CG5’s are designed to trigger only when a full cylinder is exposed to a fire, but not when the cylinder is less than full.
  • The soft, heat sensitive, eutectic metal has a history of extruding out of the PRD.
  • In the event of a fire, the eutectic is prone to solidifying in the vent tubing; thereby restricting the vent path.

All of these issues are eliminated with the use of NorAm’s CG9 and glass bulb PRD systems.

This solution does away with the eutectic metal and replaces the orifice barrier with a more reliable glass sphere which cannot be extruded due to long periods of high pressure. Further, when it bursts due to heat and pressure, there is no danger of residual blockage of the venting process.

Finally, the CG9 has a flow rate that exceeds any other product currently available. Emergency venting can occur efficiently and rapidly, thereby greatly improving safety.

Therefore, when compared to other product options, NorAm’s CG-9 PRD/TRD is:

  • Safer
  • Highly reliable
  • Designed for high flow rates
  • Easy to install

NorAm has three basic glass-bulb, PRD products for use with composite cylinders:

  • The CG-9 is a replacement for the Sherwood CG4/CG5. The CG-9 provides the composite cylinder’s PRD system with a greater level of safety and reliability
  • End plug PRD which screws directly into the end of the cylinder. The glass-bulb safety feature remains protected from external damage and tampering while still delivering all of the benefits.
  • Mongoose PRD System is specifically designed for large composite cylinders requiring multiple “triggers” to have sufficient fire protection while delivering high flow rates to prevent the rupture of the cylinder in the event of a fire. Additionally, the Mongoose allows customers to customize and easily install a fire protection system to support a variety of cylinder sizes, configurations and end-user needs.

View the spec sheet

NorAm’s safety systems are based on it’s CG-9 pressure relief device (PRD) - thermal relief device (TRD).

The US Department of Transportation requires all high pressure gas storage systems have a PRD/TRD in the event of a fire and the resulting dangerous build up of pressure that can rupture a cylinder. The traditional option is based on eutectic metal in an orifice. When a fire occurs, the metal will melt, thereby opening the vent line to enable a rapid release of gas.

There are two key problems with this option. First, over time, the eutectic metal can be forced out of the orifice which can lead to a premature release of gas. Secondly, if a fire does occur and the metal melts, not all of the molten material can be forced out of the orifice. (The Joule-Thompson Effect can resolidify the metal inside the vent line, blocking it back up again.)

NorAm’s solution does away with the eutectic metal and replaces the orifice barrier with a more reliable glass sphere which cannot be extruded due to long periods of high pressure. Further, when it bursts due to heat and pressure, there is no danger of residual blockage of the venting process.

Finally, the CG-9 has a flow rate that exceeds any other product currently available. Emergency venting can occur efficiently and rapidly, thereby greatly improving safety.

Therefore, when compared to other product options, NorAm’s CG-9 PRD/TRD is:

  • Safer
  • More reliable
  • More efficient
  • More reliable
  • Cost effective

The CG-9 PRD/TRD is used in NorAm’s END PLUG and is the basis for NorAm’s MONGOOSE PRD system to support a variety of cylinder sizes and groupings.

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