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Whenever a fire occurs in a structure served by propane or natural gas the possibility exists that the cause of that fire may be attributed to a malfunction of gas appliances, equipment or piping located in the structure. In many cases leaks may exist after a fire when they did not exist before the fire. Even though those leaks may be minor, investigators that are unfamiliar with gas systems or the properties of the gas may determine that the leak started the fire. This can subsequently result in a lawsuit against a number of parties, including the propane gas company or natural gas utility.

Authors: Jay M. Freeman

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There are numerous incidents every year where customers of natural gas and propane gas companies have losses involving fires, explosions or carbon monoxide poisonings. In many situations the gas company ends up in litigation, often well after the incident. Accordingly, it is extremely important to conduct an early assessment of the loss to determine any potential liability. It is also important that evidence at the site be examined and documented soon after the loss by experts, risk management personnel and even lawyers on more serious losses.

Authors: Jay M. Freeman

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With newer homes being constructed more tightly and older homes being sealed up with weather stripping, the margin for error with an improperly functioning gas appliance is reduced, resulting in a greater number of carbon monoxide incidents. In many cases the propane gas company or the natural gas utility becomes involved in a subsequent claim or lawsuit.

There are important steps that can be taken to minimize the number of losses of this type and there are proper ways to investigate the incidents that do occur. Time is of the essence when it comes to an investigation. Weather conditions that might be a major factor can change quickly. This paper will discuss the causes of carbon monoxide incidents, how to investigate them and ways to reduce the chance of an incident occurring.

Authors: Jay M. Freeman

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A research project into odor fade in new and used 500-gallon propane tanks was undertaken as a result of litigation related to a catastrophic explosion and subsequent fire that occurred in a modular home in the Rocky Mountain area. The test program involved twelve 500-gallon tanks of various classifications. Six tanks were new, three tanks were converted from anhydrous ammonia to propane and three tanks were old and seasoned.

Authors: John L. Schumacher, Jay M. Freeman

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Fires, explosions and carbon monoxide poisoning incidents occur every year with customers of natural gas and propane companies. When incidents do occur, gas companies typically conduct an investigation into the losses to assess liability and to prepare for potential future claims. The severity of the incident, to some degree, determines the type and sophistication of the investigation. In many cases, investigation into less severe accidents is conducted in-house. With the more serious incidents, engineers are customarily hired to conduct and direct the investigation. This paper addresses the role of the forensic engineer in the investigation of fires, explosions and carbon monoxide incidents related to potential gas company claims.

Authors: Jay M. Freeman, John L. Schumacher

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Fire and explosion incidents occur far too frequently every year in the United States. They occur in residences, commercial buildings, manufacturing facilities and chemical plants alike. These incidents cause serious injury, fatality, and large dollar loss as a result of property damage and business interruption. Determining the root cause of the fire and/or explosion is important in the prevention of future recurrences, assessing liability and preparing for potential future claims. This paper addresses the role of the forensic engineer in the effective investigation of fires and explosions involving gas and flammable liquids.

Authors: John L. Schumacher, Jay M. Freeman

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The investigation of a gas-related fire or explosion typically involves testing the integrity of the gas system. Oftentimes this testing reveals one or more leaks of various sizes. The investigator must then evaluate the cause of each leak and/or its potential in contributing to the cause of the incident. Two methods commonly used to evaluate the potential causal role of a leak are full scale testing and mathematical modeling. Although full scale testing is preferred, it may be cost prohibitive and impractical. In these cases, the alternative is mathematical modeling. The question that arises with the use of a mathematical model, however, is how accurately it predicts the gas concentrations that were actually present during the incident under investigation.

Authors: John L. Schumacher, Jay M. Freeman, Dennis E. Shelp, Zach J. Jason

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Regulators and gas control valves are at the heart of gas pressure regulation. The regulators are designed to limit the pressure delivered to the gas control valves to a specified maximum, typically 1.7 kPa (7 inches water column gauge (w.c.)) for natural gas and 3.2 kPa (13 inches w.c.) for propane. The gas control valve allows gas to flow to its associated appliance burner when there is a call for operation. The gas control valve usually has internal regulation, which reduces the manifold pressure below that of the incoming pressure, typically about 0.87 kPa (3.5 inches w.c.) for natural gas and 2.5 kPa (10 inches w.c.) for propane.

Authors: John L. Schumacher, Dennis E. Shelp, Jay M. Freeman, Zach J. Jason

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Under certain conditions the ability of a regulator to properly regulate fuel gas pressure can be affected. If a regulator problem occurs that sends high pressure gas downstream, gas-fired equipment and system components can potentially fail, which may result in a fire or explosion. This study describes the basic construction and operation of a lever-style service regulator, the type commonly used on residential and light commercial gas systems. Then, considering the mechanics of how regulators work, problematic conditions that can produce higher than normal outlet pressures are discussed and experimentally demonstrated. These examples are then discussed with regard to actual overpressure failures observed by the authors.

Authors: Dennis E. Shelp, John L. Schumacher, Jay M. Freeman, Zach J. Jason

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There are situations that occur when customers and servicemen have difficulty lighting pilots on appliances after the natural gas or propane system has been shut off or following an out-of-gas call in a
propane system. The inability to light the pilot light is believed to be due to air getting into the gas system.
In some circumstances customers or servicemen will purge the gas line in order to get the “air” out of the
lines. Sometimes this results in flammable gas entering the structure resulting in an explosion, flash fire or
fire, which causes property damage, serious injuries, and sometimes death.

Authors: Jay M. Freeman, John L. Schumacher, Dennis E. Shelp, Zach J. Jason

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Raw agricultural commodities, such as corn, soybean, rice and wheat, are typically stored in bins and silos prior to shipment. During storage, it is often necessary to protect the commodities from damage by insects and pests. A common protection method utilized is the addition of solid fumigant pellets or tablets to the commodity. One of the most common solid fumigants employed is a blend of aluminum phosphide, ammonium carbamate and other inert ingredients.

Authors: John L. Schumacher, Zach J. Jason

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Polyethylene (PE) pipe has been used as a proven means of conveying and distributing fuel gases since the 1960s.1 In the United States and Canada, PE pipe accounts for over 90% of the natural gas distribution system and has become the de facto industry standard. Although PE pipe is so prevalent, industry codes and regulations do not allow plastic pipe to be installed within a structure as a suitable means to convey fuel gas. Therefore, a coupling or fitting is used to transition from the exterior PE pipe to the metallic pipe
associated with distribution within a structure.

Authors: Zach J. Jason, John L. Schumacher, M.L. Brown, Dennis E. Shelp

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There are situations that occur when customers and servicemen have difficulty lighting pilots on appliances after a natural gas or propane system has been shut off or following an out-of-gas call in a propane system. The inability to light the pilot light is believed to be the result of air getting into the gas system. In some circumstances, customers or servicemen will purge the gas line in order to get the ‘‘air’’ out of the lines. Sometimes this results in flammable gas entering the structure leading to an explosion, flash fire or fire, and subsequently property damage, serious injuries, and sometimes death.

Authors: Jay M. Freeman, John L. Schumacher, Dennis E. Shelp, Zach J. Jason

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It is well known that cigarettes are the leading cause of fire deaths in the United States.1 The National Fire Protection Association (NFPA) reports that in 2011 alone, there were over 90,000 smoking-related fires, contributing to over 540 civilian deaths, 1,640 civilian injuries, and $621 million in direct property damage. However, the NFPA statistics, collected from The National Fire Incident Reporting System (NFIRS) and the NFPA annual survey, define “Smoking Materials” as lighted tobacco products (typically tobacco cigarettes). There is little to no data regarding fires caused by cannabis, or what will hereafter be referred to as marijuana cigarettes.

Authors: Zach J. Jason, Dennis E. Shelp, John L. Schumacher, T.J. Hedglin

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This paper reviews recent survey data related to grill ownership and usage, an references National Fire Incident Reporting System (NFIRS) data related to gas grill fires. The basic anatomy of gas grills is presented, and standards and safety devices relevant to gas grills are discussed. This background and baseline information is followed by a discussion of the causes of gas grill fires. Potential causes are considered and discussed in great detail than the generalized information available through NFIRS data, and observations based on investigation results and demonstrative tests are provided.

Authors: Dennis E. Shelp, Jay M. Freeman, John L. Schumacher, Zach J. Jason

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