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UL 1978 Grease Ducts: Enhancing Safety and Reliability in Prefabricated Systems
The Importance of UL Listings
With Schebler, you can rest assured your chimney or exhaust system delivers the certainty of fire protection and performance. That’s because our prefabricated chimney products adhere to the most stringent UL standards; when you see the UL seal, you know a product has attained the highest echelon of quality assurance. The UL mark is the most accepted certification mark in the United States — appearing on 22 billion products annually. But many of our competitor’s products cannot meet its rigorous requirements.
UL has 1,500 different standards, each representing a different application and level of protection. We wrote a previous article that thoroughly explains UL listings and their importance.
Products not qualified for a UL listing are often sold at lower prices because they are made with lower quality and may create unsafe spaces. But when it comes to fire protection, taking shortcuts means more than saving a few dollars — it means imperiling lives. About 10 fatalities a year are directly caused by chimney fires. At Schebler, we never compromise safety.
UL 1978 Grease Ducts: The UL Standard for Safety With Minimal Clearances
The UL 1978 grease duct standard covers “factory-built grease ducts and grease duct assemblies intended to be installed at reduced clearances where 18-inch (457 mm) clearance is specified in the Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations, NFPA 96, and the International Mechanical Code.” These requirements also cover modular grease duct assemblies, unwelded connections between adjoining duct parts, fittings and access doors used with grease ducts. When a grease duct is installed in a tight space, fire risks increase. This makes the UL 1978 listing critical.
UL 1978 Grease Ducts Testing and Requirements
All factory-built grease ducts that meet UL 1978 grease duct requirements undergo performance tests to ensure safety. They must remain undamaged and undiminished, and their effectiveness must not be marred in any way during and after the conclusion of each test.
The number of tests is numerous and far-reaching. They include the following:
- Temperature Test of 500ºF (260ºC).
- Abnormal Temperature Test of 1930ºF (1072ºC). This test is a continuation of the 500ºF Temperature Test.
- Leakage Test to ensure no grease leakage or grease vapor escapes through or around the joints, access doors or inlet spaces.
- Vertical Support Test to ensure the assembly that supports the grease duct is not impaired and is installed correctly.
- Strength Tests to ensure the grease duct and its parts do not break or become damaged when subjected to various impacts, including those from necessary cleaning, from a sandbag or loads equivalent to four times its weight.
- Grease Duct Joint Load Test, which is equal to four times the weight of the length of the grease duct between its supports.
- Fire and Leakage Test to ensure there is no propagation of grease vapor or flame through or around the grease duct access doors and fittings.
Additional tests include, among others, an Impact Test, a Longitudinal Force Test, a Load Test for Grease Duct Elbows, Pressure Tests for Fittings Exposed to Fire Extinguishing System Pressure Tensile Strength, Elongation and Change in Volume Tests of Gaskets and Seals, a Volume Change Test, a Density Test, a Moisture Analysis Test and a Compression Set Test.
That’s a lot of tests! As a result, a UL 1978 Grease Duct certification is extremely difficult to attain. That’s why so many of our competitors don’t bother even trying. At Schebler, we’re proud of our commitment to meeting and often exceeding these detailed requirements.
The Certainty of UL Listed Safety
UL is steadfast in its commitment to ensuring that products bearing its mark continue to perform at acceptable levels. As a result, UL Solutions performs quarterly inspections, appearing at a facility unannounced to examine parts, conduct tests and measure dimensions. They even check product labels for accuracy. If UL uncovers a violation, it can completely halt production of that product at the factory.
At Schebler, we have been UL-certified since 1994 and have never received a single major violation. This certainty is one of the key reasons we’re the unquestioned leader in providing the finest prefabricated chimney and exhaust systems.
Contact us to learn more about our chimney solutions.
