top of page

Remote learning support

Public·12 members

UL 1709: Best Practices and Tips for Selecting and Applying PFP Materials for Structural Steel in Hydrocarbon Fires


UL 1709: The Standard for Rapid Rise Fire Tests of Protection Materials for Structural Steel




The protection of structural steel from the effects of hydrocarbon-based fires, such as those experienced in chemical, oil and gas production and distribution facilities, is a critical safety issue for the petrochemical industry. In order to evaluate the performance of passive fire protection (PFP) materials applied to structural steel members, a standard test method known as UL 1709 was developed by Underwriters Laboratories (UL), a global leader in safety science.




ul 1709 pdf free 63


Download File: https://www.google.com/url?q=https%3A%2F%2Ftweeat.com%2F2ucv6H&sa=D&sntz=1&usg=AOvVaw1Mh8PY8Bg7vAhbFjtfYSKm



UL 1709, Rapid Rise Fire Tests of Protection Materials for Structural Steel, describes a full-scale fire exposure test that simulates a rapid-temperature-rise fire scenario that can occur in a hydrocarbon fire. The standard measures the resistance of PFP materials to withstand the fire exposure and protect the structural steel from reaching a critical temperature that could compromise its load-bearing capacity.


In this article, we will provide an overview of UL 1709 and its importance for the petrochemical industry. We will also discuss the background and requirements of UL 1709, as well as the anticipated changes in UL 1709 5th Edition that will be published in 2015. Finally, we will introduce UL's expanded certification scheme for PFP materials used to protect structural steel in petrochemical plants and facilities.


Background




Structural steel is widely used in petrochemical plants and facilities because of its strength, durability and versatility. However, structural steel is also vulnerable to high temperatures that can reduce its strength and cause it to collapse. In a hydrocarbon fire, such as a jet fire or a pool fire, the temperature can rise rapidly to over 1000C (1832F) within minutes, creating a severe threat to the structural integrity of steel members.


To prevent or delay the failure of structural steel in a hydrocarbon fire, PFP materials are applied to provide thermal insulation and protection. PFP materials can be classified into two types: reactive and non-reactive. Reactive PFP materials are those that undergo a chemical or physical change when exposed to fire, such as intumescent coatings that swell and form a char layer, or ablative coatings that erode and dissipate heat. Non-reactive PFP materials are those that do not change when exposed to fire, such as cementitious or mineral fiber products that provide a barrier layer.


In order to ensure the adequacy and reliability of PFP materials for structural steel, various codes and standards have been developed to specify the minimum fire resistance requirements and testing methods. Some of the most widely used codes and standards in the petrochemical industry are:


  • The American Petroleum Institute (API) standards, such as API 2218, Fireproofing Practices in Petroleum and Petrochemical Processing Plants, and API RP 2FB, Recommended Practice for the Design of Offshore Facilities Against Fire and Blast Loading, which provide guidance on the selection, installation and maintenance of PFP materials for structural steel in different petrochemical applications.



  • The International Organization for Standardization (ISO) standard, ISO 22899-1, Determination of the resistance to jet fires of passive fire protection materials - Part 1: General requirements, which describes a test method for measuring the resistance of PFP materials to jet fires.



  • The ASTM International (ASTM) standard, ASTM E1529, Standard Test Methods for Determining Effects of Large Hydrocarbon Pool Fires on Structural Members and Assemblies, which describes a test method for measuring the effects of pool fires on structural members and assemblies.



Among these codes and standards, UL 1709 is considered to be the most stringent and comprehensive test method for evaluating the performance of PFP materials for structural steel in hydrocarbon fires. UL 1709 was first published in 1989 and has since been revised four times, with the latest edition being published in 2007. UL 1709 is referenced by many API standards and is widely accepted in many parts of the world, particularly in North America, Europe, Middle East and Asia.


Requirements of UL 1709




UL 1709 describes a test method for measuring the resistance of PFP materials to rapid-temperature-rise fires. The test method covers a full-scale fire exposure test, intended to evaluate the thermal resistance of PFP materials applied to structural members and the ability of the PFP materials to withstand the fire exposure. The test method also includes a supplementary test method for beams, intended to evaluate the ability of PFP materials to perform when subject to significant deflections.


Test Procedures and Criteria




The full-scale fire exposure test is conducted in a gas-fired furnace that can generate a fire with a temperature-time curve as specified in UL 1709. The temperature-time curve represents a rapid-temperature-rise fire scenario that can occur in a hydrocarbon fire. The curve starts at ambient temperature and reaches 1093C (2000F) within five minutes, then maintains at 1093C (2000F) for the duration of the test. The test duration depends on the type and size of the structural member being tested, but typically ranges from 15 minutes to 4 hours.


The structural members that can be tested according to UL 1709 include columns, beams, girders, trusses, braces and other sections that are commonly used in petrochemical plants and facilities. The structural members are fabricated from steel sections with different shapes, sizes and grades as specified in UL 1709. The structural members are coated with PFP materials according to the manufacturer's instructions and conditioned before testing.


The structural members are instrumented with thermocouples to measure the temperature of the steel surface and the PFP material during the test. The thermocouples are attached at various locations along the length and cross-section of the structural member. The thermocouples are connected to a data acquisition system that records the temperature readings throughout the test.


The structural members are loaded with a constant axial or bending load that simulates the design load of the member in service. The load is applied by a hydraulic or mechanical loading system that is independent of the furnace. The load is maintained throughout the test unless failure occurs.


The structural members are placed horizontally or vertically inside the furnace depending on their orientation in service. The furnace is ignited and controlled to follow the temperature-time curve as specified in UL 1709. The furnace is equipped with observation windows and cameras to monitor the behavior of the structural member and the PFP material during the test.


The test is terminated when one of the following criteria is met:


  • The steel temperature at any thermocouple location exceeds 538C (1000F), which is considered as the critical temperature for structural steel in a hydrocarbon fire.



  • The load-carrying capacity of the structural member is lost due to buckling, bending or fracture.



  • The PFP material fails to remain intact or adhered to the steel surface due to spalling, cracking or delamination.



  • The specified test duration is reached.



The supplementary test method for beams is conducted on a horizontal beam that is loaded with a constant bending moment at both ends. The beam is coated with PFP material and instrumented with thermocouples as in the full-scale fire exposure test. The beam is exposed to the same temperature-time curve as specified in UL 1709. The test is terminated when one of the following criteria is met: - The steel temperature at any thermocouple location exceeds 538C (1000F). - The PFP material fails to remain intact or adhered to the steel surface due to spalling, cracking or delamination. - The specified test duration is reached. The supplementary test method for beams is used to evaluate the effect of deflection on the performance of PFP materials. The deflection of the beam is measured by a linear variable differential transformer (LVDT) or a similar device during the test. The deflection data is used to calculate the strain in the PFP material and the steel section. The strain data is then used to derive product design tables for beams and other sections subject to bending. Limits of Applicability and Classification




The test results obtained from UL 1709 are valid only for the specific type and size of structural member, PFP material, load level and fire exposure tested. The test results cannot be extrapolated or interpolated to other conditions without proper justification and verification. Therefore, UL 1709 specifies the limits of applicability of test results for different types of structural members and PFP materials.


The limits of applicability are based on factors such as the shape factor, the slenderness ratio, the load ratio, the thickness ratio and the density ratio of the structural member and the PFP material. These factors are defined and calculated according to UL 1709. The limits of applicability define the range of values for these factors that are covered by the test results. For example, if a column with a shape factor of 1.2 and a slenderness ratio of 50 is tested with a PFP material with a thickness ratio of 0.1 and a density ratio of 0.8, then the test results are applicable to columns with shape factors between 1.0 and 1.4, slenderness ratios between 40 and 60, PFP materials with thickness ratios between 0.08 and 0.12, and density ratios between 0.7 and 0.9.


The classification of UL 1709 test results is based on the fire resistance rating achieved by the structural member and the PFP material under the specified fire exposure and load level. The fire resistance rating is expressed in hours or minutes and indicates the duration of time that the structural member and the PFP material can withstand the fire exposure without exceeding the failure criteria. For example, if a column with a PFP material can withstand a fire exposure for 2 hours without exceeding the steel temperature limit of 538C (1000F), then it is classified as having a fire resistance rating of 2 hours.


Changes in UL 1709 5th Edition




UL 1709 is currently undergoing revision and is expected to be published in 2015 as UL 1709 5th Edition. The revision aims to update the legacy testing requirements for PFP materials to include newer environmental conditioning tests, and variations in steel section sizes that are covered by the test standard. The revision also aims to introduce a more holistic certification scheme for PFP materials that includes optional performance characteristics such as exposure to fire via high-pressure jets and environmental durability. Newer Environmental Conditioning Tests




One of the major changes in UL 1709 5th Edition is the inclusion of newer environmental conditioning tests for PFP materials. These tests are intended to evaluate the durability and performance of PFP materials under various environmental conditions that can affect their integrity and functionality. The environmental conditioning tests are based on UL 2431, Standard for Durability Testing of Fire Resistive Materials, which was published in 2014.


The environmental conditioning tests include exposure to weathering, humidity, salt spray, acid spray, alkali spray, industrial atmosphere, thermal cycling and mechanical damage. The PFP materials are subjected to these tests before and after the full-scale fire exposure test or the supplementary test method for beams. The test results are compared to determine the effect of environmental conditioning on the fire resistance rating and the failure criteria of the PFP materials.


The environmental conditioning tests are mandatory for all PFP materials that are intended to be used in outdoor or corrosive environments. The tests are also applicable for PFP materials that are intended to be used in indoor environments where they may be exposed to moisture, temperature changes or mechanical damage. The tests are not applicable for PFP materials that are intended to be used in indoor environments where they are protected from environmental exposure.


Variations in Steel Section Sizes




Another major change in UL 1709 5th Edition is the introduction of variations in steel section sizes that are covered by the test standard. These variations are intended to provide more flexibility and applicability for different types and sizes of structural steel members that are commonly used in petrochemical plants and facilities. The variations are based on factors such as the shape factor, the slenderness ratio, the load ratio, the thickness ratio and the density ratio of the structural member and the PFP material.


The variations in steel section sizes allow for testing and certification of PFP materials for structural steel members with different cross-sectional shapes, such as I-shaped, H-shaped, C-shaped, L-shaped and T-shaped sections. The variations also allow for testing and certification of PFP materials for structural steel members with different cross-sectional dimensions, such as width, depth, flange width, flange thickness, web thickness and radius of gyration. The variations also allow for testing and certification of PFP materials for structural steel members with different steel grades, such as A36, A572 and A992.


The variations in steel section sizes are based on a multi-section analysis that determines the equivalent section size and shape that can represent a range of section sizes and shapes with similar performance characteristics. The multi-section analysis is conducted using a finite element model that simulates the thermal and mechanical behavior of structural steel members and PFP materials under fire exposure. The multi-section analysis is validated by comparing the results with experimental data obtained from UL 1709 tests.


UL's Expanded Certification Scheme for Structural Steel PFP Materials




In addition to revising UL 1709, UL has also developed a new certification category for PFP materials used to protect structural steel in petrochemical plants and facilities. The new certification category is called BYFH - Fire Resistance Hydrocarbon. The new certification category includes tests to evaluate optional performance characteristics over and above UL 1709. These optional performance characteristics include exposure to fire via high-pressure jets and environmental durability.


Exposure to Fire via High-Pressure Jets




This optional performance characteristic evaluates the resistance of PFP materials to fire via high-pressure jets. High-pressure jets are streams of hydrocarbon fuel that are ejected at high velocity and pressure from a nozzle or a pipe rupture. High-pressure jets can create intense localized heating and erosion on structural steel members and PFP materials.


The test method for exposure to fire via high-pressure jets is based on ISO 22899-1, Determination of the resistance to jet fires of passive fire protection materials - Part 1: General requirements. The test method involves exposing a horizontal beam coated with PFP material to a jet fire with a heat flux of 250 kW/m2 and a velocity of 50 m/s for a duration of 120 minutes. The test method measures the temperature of the steel surface and the PFP material, as well as the mass loss and erosion rate of the PFP material.


The test results are used to determine the fire resistance rating and the failure criteria of the PFP material under jet fire exposure. The test results are also used to derive product design tables for beams and other sections subject to jet fire exposure.


Environmental Durability




This optional performance characteristic evaluates the durability and performance of PFP materials under various environmental conditions that can affect their integrity and functionality. The environmental conditions include exposure to weathering, humidity, salt spray, acid spray, alkali spray, industrial atmosphere, thermal cycling and mechanical damage.


The test method for environmental durability is based on UL 2431, Standard for Durability Testing of Fire Resistive Materials. The test method involves exposing PFP materials to different environmental conditions before and after the full-scale fire exposure test or the supplementary test method for beams. The test method measures the temperature of the steel surface and the PFP material, as well as the mass loss and erosion rate of the PFP material.


The test results are used to determine the effect of environmental conditioning on the fire resistance rating and the failure criteria of the PFP material. The test results are also used to derive product design tables for beams and other sections subject to environmental exposure.


Conclusion




UL 1709 is a standard test method for measuring the resistance of PFP materials to rapid-temperature-rise fires that can occur in hydrocarbon fires. UL 1709 is widely used and accepted in the petrochemical industry for evaluating the performance of PFP materials for structural steel members. UL 1709 is currently undergoing revision and is expected to be published in 2015 as UL 1709 5th Edition. The revision will update the testing requirements for PFP materials to include newer environmental conditioning tests, and variations in steel section sizes that are covered by the test standard.


UL has also developed a new certification category for PFP materials used to protect structural steel in petrochemical plants and facilities. The new certification category is called BYFH - Fire Resistance Hydrocarbon. The new certification category includes tests to evaluate optional performance characteristics over and above UL 1709. These optional performance characteristics include exposure to fire via high-pressure jets and environmental durability.


UL's revised UL 1709 and expanded certification scheme will provide more flexibility and applicability for different types and sizes of structural steel members and PFP materials that are commonly used in petrochemical plants and facilities. UL's testing and certification services will help manufacturers, specifiers and users of structural steel PFP materials to ensure their adequacy and reliability under various fire scenarios and environmental conditions.


FAQs




What is the difference between hydrocarbon fires and cellulosic fires?




Hydrocarbon fires are fires that involve hydrocarbon fuels such as petroleum, natural gas, diesel, gasoline, jet fuel, etc. Hydrocarbon fires have a rapid temperature rise and a high heat flux that can reach over 1000C (1832F) within minutes. Cellulosic fires are fires that involve cellulosic materials such as wood, paper, cotton, etc. Cellulosic fires have a slower temperature rise and a lower heat flux that can reach up to 800C (1472F) over hours.


What are some examples of passive fire protection materials for structural steel?




Some examples of passive fire protection materials for structural steel are intumescent coatings, ablative coatings, cementitious products, mineral fiber products, board systems, etc. These materials provide thermal insulation and protection for structural steel members by forming a barrier layer or a char layer when exposed to fire.


How can I find out if a product is certified by UL for UL 1709?




You can find out if a product is certified by UL for UL 1709 by checking the UL Product iQ database at https://productiq.ul.com/. You can search by product name, manuf


About

Welcome to the group! You can connect with other members, ge...
bottom of page