What is UL 722 ?

Title: What is UL 722 and UL 724: Setting Safety Standards for Fire-Resisting Ductwork and Equipment?

The safety of occupants and the environment is of utmost importance in any construction or renovation project. One of the critical aspects that need to meet or exceed standards is fire-resisting ductwork systems. As such, Underwriters Laboratories (UL) has developed two important standards that serve as the foundation of their fire safety certification program. These standards are UL 722 and UL 724, and they are designed to ensure that duct systems and equipment used in hazardous locations meet the necessary safety criteria.

What is UL 722?

UL 722 is a standard developed by UL to address the issue of fire-resisting ductwork systems. It sets the requirements and testing procedures for ducts designed to withstand fire incidents. The main purpose of UL 722 is to ensure that duct systems in buildings can contain fire within designated areas, preventing further spread and protecting occupants from smoke inhalation, heat, and potential harm.

UL 722 addresses various aspects, including fire resistance, structural stability during exposure to fire, and thermal insulation properties of duct materials. The standard provides a framework for manufacturers to ensure that their duct products meet the necessary criteria for fire resistance, while also providing a standardized testing procedure to validate the products' performance.

What is UL 724?

UL 724 is another standard developed by UL to address the issue of safety requirements for equipment used in hazardous locations. It ensures that such equipment meets specific criteria to prevent accidents and potential explosions. The purpose of UL 724 is to establish safety guidelines for electrical equipment used in hazardous environments, such as factories or oil refineries, where the presence of flammable gases or vapors necessitates special precautions to prevent fires or explosions.

UL 724 helps ensure that equipment is adequately designed, constructed, and marked to mitigate the risk of ignition when operating in these potentially dangerous environments. The standard provides a framework for manufacturers to ensure that their equipment meets the necessary safety criteria, while also providing a standardized testing procedure to validate the equipment's performance.

Key Requirements of UL 722 and UL 724

Both UL 722 and UL 724 are designed to ensure that electrical equipment and duct systems are safe to use in hazardous environments. The key requirements of these standards are as follows:

Fire Resistance:

UL 722 and UL 724 both require that the materials used in the construction of fire-resisting ducts be fire-resistant. The materials must be able to withstand the ignition and combustion of the materials, as well as the spread of fire through the material.

Structural Stability:

UL 722 and UL 724 both require that the ducts be able to withstand the weight and the effects of fire, such as heat and smoke, without collapsing or sustaining damage.

Thermal Insulation:

UL 722 and UL 724 both require that the materials used in the construction of the ducts provide thermal insulation to prevent heat from being transferred to the fire-resistant material.

Testing:

Both UL 722 and UL 724 require manufacturers to conduct testing to ensure that their products meet the necessary safety criteria. The testing should be designed to verify that the products are safe to use in the hazardous environments in which they will be used.

Conclusion:

UL 722 and UL 724 are important standards that help ensure the safety of electrical equipment and duct systems used in hazardous environments. These standards provide a framework for manufacturers to ensure that their products meet the necessary safety criteria, while also providing a standardized testing procedure to validate the products' performance. By following the key requirements of these standards, manufacturers can ensure that their products are safe to use in the hazardous environments in which they will be used.