Southwest Research Institute 2000 Annual Report, Fire Technology

On a national and international scale, the Institute's fire technology program provides technical leadership in the areas of fire testing, research and engineering, consultation, and listing and labeling services. SwRI's facilities include unique testing capabilities and specialized equipment. Institute scientists perform fire research on behalf of government and commercial clients in the construction, transportation, telecommunications, utility, chemical, and petrochemical industries.

Building and fire codes limit the volume of commodities stored in warehouses and set requirements for sprinklers and smoke vents. To measure heat release, smoke production, and temperatures from fires in typical warehouse configurations, SwRI engineers use intermediate- and large-scale calorimeters. The measurements help researchers evaluate hazards potentially caused by stored commodities and aid in the design of suitable fire suppression and safety systems. SwRI engineers store commodities ranging from paper products to flammable liquids to reactive chemicals in simulated warehouse configurations to determine flame spread, damage levels, and fire control time. The data allow engineers to propose combined storage and suppression strategies that increase safety and minimize commodity losses in the event of a fire.

Fire research programs for the natural gas industry continue to expand. SwRI engineers conducted experimental and analytical studies to determine the ignition mechanics and sustainability of fires within confined volumes, such as underground vaults. These tests provided critical information for the applicability of codes and regulations. In one test, gas regulator devices were subjected to a jet fire fueled by natural gas from a simulated severed control line. SwRI researchers found that the fire's sustainability depended on aspiration characteristics such as air vents and manhole openings.

Environmental considerations in the design and development of electrical and electronic equipment play a fundamental role in creating systems that are safe and durable. Some equipment is designed for hostile operational environments, including sensors and test equipment used in the vicinity of aircraft, racked and wheeled vehicles, or typical civilian and military marine applications. SwRI built an explosive atmosphere test apparatus to determine the operational and survivability characteristics of equipment in harsh environments and to assess their propensity for igniting in an explosive atmosphere.

For the U.S. Air Force, engineers installed a laptop computer in SwRI's explosive atmosphere test facility to simulate service usage, which included making and breaking electrical power connections and attaching auxiliary, electrically driven instruments. The tests demonstrated the ability of the computer and similar electronics to be operated in explosive atmospheres, such as those found in the aircraft, automotive, and marine system industries, without causing ignition. Testing criteria focused on the typical operation of the computer to demonstrate that it would not ignite an ambient explosive-gaseous mixture.

The Institute provides analysis and testing services to help clients manage the potential hazards of energetic and reactive chemicals during transport. Energetic and reactive materials can react under certain conditions, generating high temperatures and pressures during reaction. The generation of excessive heat and pressures typically occurs very quickly, creating serious safety hazards. Improper handling or misuse of some chemicals can increase the rate at which they react. The high rate of reaction and the potential inability to control energetic and reactive chemicals distinguish these products and warrant special precautions and designations. The Institute helps industry understand the potential hazards and meet national and international safety regulations applicable to these materials.

Newly enacted building and fire code requirements for Exterior Insulation and Finish Systems (EIFS) have resulted in the expansion of the Institute's listing, labeling, and follow-up inspection services - a program which lists and labels products that show acceptable fire, acoustical, structural, physical, or environmental performance. The codes now require that coatings used on EIFS be under a third-party follow-up program. In response, SwRI developed a program and listing category for regulatory compliance that also includes structural and environmental performance testing. These tests measure durability, structural, and weather-resistant characteristics of building materials. The new facilities, coupled with existing fire testing capabilities, offer clients in the construction industry a one-stop laboratory for conducting the range of tests required by regulatory bodies.

SwRI administers one of the world's largest listing, labeling, and follow-up inspection service programs for aboveground storage tanks containing flammable and combustible liquids. During the past year, 65 members of the Steel Tank Institute from the U.S., Canada, and Mexico, joined the Institute's listing and labeling program as approved manufacturers of fire-resistant tanks. The program ensures that the product that reaches the consumer is manufactured in the same manner as the product evaluated and tested by SwRI.

The Institute evaluates fuel-derived hydrocarbon emissions from fuel system components in a 2,000-square-foot permeation facility. The facility houses two mini-SHEDs (Sealed Housing for Evaporative Determinations) equipped with gas chromatographs that are capable of isothermal or gradient temperature profiles from -30 to 180 deg F. Use of the facility was expanded to test composite pipes, which are replacing metal pipes in the transmission of natural gas at high pressure. This capability has also drawn attention from the composite pipe industry for possible application in fuel and gas transmission systems.

Smoke toxicity studies remain an important part of SwRI's fire technology program. Increased attention to the types of materials used in closed compartments has mandated more accurate smoke and toxicity measurements. Habitable areas on surface and subsurface ships and aircraft are examples of areas where combustible materials need to be evaluated for toxicity. State-of-the-art equipment for chemical analysis of combustion by-products is used to identify and quantify toxicity levels. These analyses help clients determine the safety of their products.

An industry-scale calorimeter has been installed in SwRI's newest temperature-controlled, 4,000-square-foot building dedicated to heat release rate measurements based on oxygen consumption. The calorimeter is designed to handle fires such as those from commodities, automobiles, and railcar sections, with heat release rates of up to 10 megawatts. Several programs have been conducted since its installation, including a pool fire study to evaluate the burning characteristics of heptane, methanol, and other flammable and combustible liquids.

Copyright© 2001 by Southwest Research Institute. All rights reserved under U.S. Copyright Law and International Conventions. No part of this publication may be reproduced in any form or by any means, electronic or mechanical, including photocopying, without permission in writing from the publisher. All inquiries should be addressed to Communications Department, Southwest Research Institute, P.O. Drawer 28510, San Antonio, Texas 78228-0510, phone (210) 522-2257, fax (210) 522-3547.