Jun 2013

An Updated Look at Protection in Glass Manufacturing Plants

Occasionally loss prevention procedures need revision as we learn more about how to protect the hazard. In January 2008 we wrote a comprehensive article on Property Loss Prevention in Glass Manufacturing Plants. This month we’ve chosen to add some additional information to that article.


Automatic sprinkler protection should be provided where combustible construction, storage and combustible / flammable liquids are located. Most areas of a glass plant will require automatic sprinkler protection for these reasons, with the exception of the furnace area. In the furnace area (and areas adjacent to the furnace) there should be no combustibles present. It is important to provide hose connections for both solid stream and spray nozzles. Employees should be trained in the application of each nozzle, so that they know when and where to apply the hose stream. A portable, 300 lb. capacity, wheeled dry chemical fire extinguisher should be located next to each furnace. Again, training should be provided for the use of the extinguisher.

Combustible Insulation:

Insulation on HVAC ductwork is critical to maintain the proper heating and cooling in the process. FM approved insulation is needed in the areas not protected by automatic sprinkler protection. “Knockoff” insulation, which appears to be FM approved, has become prevalent. Armacell Engineered Foams, manufactured by Armaflex, is a common insulation in the manufacturing industry. The Armaflex Class 1 product is FM approved; however, knockoffs that look similar to this product are now being found during routine property loss prevention inspections. It is important that the FM approved product be installed, particularly in areas not protected by automatic sprinkler protection.


Alarms should be provided for the thermocouples located on the furnace, as well as for the process water and air that are critical to the performance of the furnace. The alarm signal should be sent to a constantly attended control room.

Process Equipment:

FM approved equipment is critical to the fire protection industry. The trademark provides a sense of security that the equipment has been put through rigorous testing applications and is considered reliable. If FM approval is provided for critical equipment such as process water pumps and safety shutoff valves, then serious consideration should be made in selecting the FM approved equipment. Also, gravity fed process water tanks provide more reliability in a power outage than process water pumps fed from water supply tanks.

Grouped Cable

A power outage at a glass plant can have enormous business interruption implications. Most electrical / power control rooms are very large. Either a gaseous protection system or an automatic sprinkler system should be installed. Local detection should also be provided within the power control units, as should a VESDA system.

During installation, if an automatic sprinkler protection or a gaseous suppression system is not provided in the electrical / power control room, then FM approved Group 1, UL 910 plenum rated cable with a flame spread that does not exceed 5 ft. when tested in accordance with NFPA 262 should be provided. If it is determined – after the fact – that the cable is combustible and there is no protection in the room, then a less desirable protection feature would be to apply an FM approved coating to the group or bundled cable. It is important that the coating not flake or produce a residue on the electrical equipment.

Molten Glass

As indicated in our January 2008 article, it is important that a bund (masonry dike) be provided to fully contain the entire content capacity of the tank. The bund should be a minimum of 3 feet. If a molten glass release occurs, there will be a significant amount of heat underneath the tank area. It is important to be prepared for this heat release. Critical electrical / power cables need to be protected as well as the gas fuel line.

Risk Logic has the capability and experience to evaluate property loss prevention risks and recommend ways to improve them in glass manufacturing facilities.