5.1 Brass components are routinely used in compressed gas service for valves, pressure regulators, connectors and many other components. Although soft brass is not susceptible to ammonia SCC, work-hardened brass is susceptible if its hardness exceeds about 54 HR 30T (55HRB) (Rockwell scale). Normal assembly of brass components should not induce sufficient work hardening to cause susceptibility to ammonia SCC. However, it is has been observed that over-tightening of the components will render them susceptible to SCC, and the problem becomes more severe in older components that have been tightened many times. In this test, the specimens are obtained in the hardened condition and are strained beyond the elastic limit to accelerate the tendency towards SCC.5.2 It is normal practice to use LDFs to check pressurized systems to assure that leaking is not occurring. LDFs are usually aqueous solutions containing surfactants that will form bubbles at the site of a leak. If the LDF contains ammonia or other agent that can cause SCC in brass, serious damage can occur to the system that will compromise its safety and integrity.5.3 It is important to test LDFs to assure that they do not cause SCC of brass and to assure that the use of these products does not compromise the integrity of the pressure containing system.5.4 It has been found that corrosion of brass is necessary before SCC can occur. The reason for this is that the corrosion process results in cupric and cuprous ions accumulating in the electrolyte. Therefore, adding copper metal and cuprous oxide (Cu2O) to the aqueous solution accelerates the SCC process if agents that cause SCC are present. However, adding these components to a solution that does not cause SCC will not make stressed brass crack.5.5 Repeated application of the solution to the specimen followed by a drying period causes the components in the solution to concentrate thereby further increasing the rate of cracking. This also simulates service where a system may be tested many times during its life. These features of the test method accelerate the test and allow an answer to be obtained more rapidly.5.6 This test method applies only to brasses. Successful passage of this test does not assure that the LDF will be acceptable for use on other alloy systems such as stainless steels or aluminum alloys.1.1 This test method covers an accelerated test method for evaluating the tendency of gas leak detection fluids (LDFs) to cause stress corrosion cracking (SCC) of brass components in compressed gas service.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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4.1 This guide may be used in the investigation of underground storage tank systems for equipment problems in a wide variety of applications. Use of this guide is voluntary. It is intended to assist users who want to investigate equipment failures, malfunctions, and other potential causes of suspected releases.4.2 The following groups of users may find the guide particularly helpful:4.2.1 Storage tank system designers and manufacturers;4.2.2 Storage tank installers, testers, and inspectors;4.2.3 Storage tank maintenance contractors;4.2.4 Storage tank removal contractors;4.2.5 Federal, state, tribal or local regulators, including departments of health, departments of environmental protection, and fire departments;4.2.6 Petroleum release remediation professionals;4.2.7 Insurance adjusters;4.2.8 Storage tank owners and operators;4.2.9 Consultants, auditors, and compliance assistance personnel.4.3 This guide is intended to assist in the development of protocols for determination of source and cause of a release and the investigation of a malfunction or failure of any component of a UST system and the implementation of said protocols. This guide outlines steps that may be necessary and include, but are not limited to initial evaluation of the UST system to determine if there has been a component failure preparation of samples of failed or compromised equipment for laboratory analysis; visual; and analytical evaluation of release indications; and documentation of the investigation. The guide provides a series of investigation options from which the user may design failure investigation protocols. The guide describes common investigation techniques in the order in which they might be employed in an investigation.4.4 A user may elect to utilize this guide for a number of reasons, which include, but are not limited to:4.4.1 To differentiate new releases from new discovery of old releases;4.4.2 To establish malfunction and failure rates of various UST system components;4.4.3 To determine expected life spans of various UST components;4.4.4 To identify opportunities for improving the performance and reliability of storage tank equipment;4.4.5 To focus inspection and maintenance efforts on those component of the UST system that are most prone to compromise, malfunction and failure;4.4.6 To identify those components of the UST system that require more frequent maintenance;4.4.7 To reduce equipment replacement costs;4.4.8 To prevent petroleum releases;4.4.9 To identify those conditions that may cause or contribute to equipment or component compromise, deterioration or other cause of malfunction or failure of the UST system;4.4.10 To comply with environmental regulations that require the investigation of suspected releases and determine the source and cause of releases; and4.4.11 To identify conditions that may cause or contribute to nonsudden releases that may not be detected by other leak detection methods.4.5 This guide may be used to establish a framework that pulls together the common approaches to investigation. The framework will allow the user to establish an investigation protocol to meet the user’s specific requirements. Specific user requirements will vary depending upon the purposes of the data collection and the decisions that the investigation is intended to support. This guide does not provide methods to establish specific user investigation requirements nor does it establish minimum levels of documentation.4.6 This guide will acquaint users with methods and tools that may be used in investigations of equipment problems associated with USTs. The user may include a subset of the methods described in this guide in their investigation. The user may consider a variety of factors in determining which combination of the methods to employ.4.7 This guide is not intended to require the user to conduct a failure investigation.4.8 This guide is focused on the identification, documentation, and preservation of compromised UST system equipment. It does not provide guidance on establishing root causes of compromise, malfunction or failure. The identification of root causes of compromise, malfunction or failure may require further expert analysis of the data and equipment collected during the failure investigation.4.9 Determination of equipment failures and evidence of the source and cause of a release are often unavailable due to the loss of critical information necessary to pinpoint equipment failures and conduct an investigation. Adjustment, repair or removal of failed equipment before determining and documenting the cause of the failure may interfere with the failure investigation. Failures may be caused by compatibility issues, manufacturer defects, corrosion, degradation, improper installation, damage, age, misuse, use or other causes. This guide may be used to identify techniques and procedures applicable to maintenance personnel and equipment vendors that will allow an investigator to evaluate possible equipment failures before equipment is adjusted, repaired, replaced or destroyed.4.10 This guide does not address all the safety measures that must be taken when removing and disassembling UST systems. Because most UST systems have contained flammable or combustible liquids special precautions should be taken to prevent fire, explosions and exposure to toxic vapors. API standard STD 2015 and RP 2016 address some of the safety considerations as do many of the procedures available from fire departments.1.1 Overview—This guide is an organized collection of information and series of options for industry, regulators, consultants and the public, intended to assist with the development of investigation protocols for underground storage tank facilities in the United States. While the guide does not recommend a specific course of action, it establishes an investigation framework, and it provides a series of techniques that may be employed to: identify equipment problems; in some cases collect and preserve failed equipment for forensic evaluation or laboratory analysis; identify the source of a release; and document the investigation. The guide includes information on methods of investigation, documentation, collecting and preserving samples; chain of custody; storage; shipping; working with equipment manufacturers; and notification of regulators and listing laboratories. The goal in using the guide is to identify the appropriate level of investigation and to gather and preserve information, in an organized manner, which could be used in the future to improve system design or performance. While this guide may act as a starting point for users with limited experience in failure investigation, the user is encouraged to consult with failure analysis experts for specific investigation procedures that may be needed for certain equipment and the investigation should be conducted by a qualified professional. As users develop their specific investigation protocols, they may find that the investigations can be streamlined for certain types of facilities.1.2 Limitations of This Guide: 1.2.1 Given the variability of the different investigators that may wish to use this guide and the different types of facilities and failures that will be investigated, it is not possible to address all the relevant standards that might apply to a particular investigation. This guide uses generalized language and examples to guide the user. If it is not clear to the user how to apply standards to their specific circumstances, it is recommended that users seek assistance from qualified professionals.1.2.2 This guide does not address safety issues associated with the investigation, taking samples and storing equipment. Users are cautioned to exercise proper care in handling equipment that was in contact with flammable and combustible liquids and vapors. Some of the activities described in this guide may be subject to OSHA (Occupational Safety and Health Administration) regulations or may only be conducted by individuals with appropriate HAZWOPER (Hazardous Waste Operations and Emergency Response) training certifications recognized by federal and state regulatory authorities, such as HAZWOPER training.1.2.3 This guide does not address laboratory investigations of material properties and detailed failure analysis.1.2.4 This guide does not cover underground storage tank systems storing liquefied petroleum gas (LPG).1.2.5 This guide does not replace state-required closure assessments and investigations. Requirements vary from state to state and often include specific sampling requirements. The user should comply with the requirement of the authority having jurisdiction.1.2.6 Prior to implementing the steps described in Section 5, users of this guide must determine if the authority having jurisdiction has any qualification requirements for the individual performing the investigation.1.2.7 Investigations addressed by this guide may involve knowledge, skills, and abilities generally attributed to individuals certified as tank systems installers, inspectors, or removers, or those who are trained in soil and groundwater sampling protocols (for example, geologists, groundwater professionals, or engineers).1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 Embrittlement is a form of intercrystalline cracking that is associated with the exposure of boiler steel to a combination of physical and chemical factors. For embrittlement of boiler metal to occur, the metal must be under stress, it must be at the site of a leak, and it must be exposed to the concentrated boiler water. In addition, the boiler water must be embrittling in nature. The precise chemical causes of the embrittling nature of some waters are not well understood. Experience has shown that certain waters exhibit an embrittling characteristic while others do not.5.2 Because embrittlement is a form of cracking, it is nearly impossible to detect in an operating boiler until a failure has occurred. In general, cracking failures tend to be sudden, and often with serious consequences. This practice offers a way to determine whether a particular water is embrittling or not. It also makes it possible to determine if specific treatment actions have rendered the water nonembrittling.5.3 The embrittlement detector was designed to reproduce closely the conditions existing in an actual boiler seam. It is considered probable that the individual conditions of leakage, concentration, and stress in the boiler seam can equal those in the detector. The essential difference between the detector and the boiler is that the former is so constructed and operated that these three major factors act simultaneously, continuously, and under the most favorable circumstances to produce cracking; whereas, in the boiler the three factors are brought together only under unique circumstances. Furthermore, in the detector any cracking is produced in a small test surface that can be inspected thoroughly, while the susceptible areas in a boiler are large and can be inspected only with difficulty. In these respects the embrittlement detector provides an accelerated test of the fourth condition necessary for embrittlement, the embrittling nature of the boiler water.1.1 This practice,3 known as the embrittlement-detector method, covers the apparatus and procedure for determining the embrittling or nonembrittling characteristics of the water in an operating boiler. The interpretation of the results shall be restricted to the limits set forth in 8.6.NOTE 1: Cracks in a specimen after being subjected to this test indicate that the boiler water can cause embrittlement cracking, but not that the boiler in question necessarily has cracked or will crack.1.2 The effectiveness of treatment to prevent cracking, as well as an indication of whether an unsafe condition exists, are shown by this practice. Such treatments are evaluated in terms of method specimen resistance to failure.1.3 The practice may be applied to embrittlement resistance testing of steels other than boiler plate, provided that a duplicate, unexposed specimen does not crack when bent 90° on a 2-in. (51-mm) radius.1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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This practice covers the selection of tests for determining the propensity of materials used in medical devices to affect the immune system. That is, the foreign material introduced into the body may affect the humoral immune response (such as effect on specific immune response and on B cell numbers), the cell mediated response (such as response of T cells), the inflammatory factors, and complement (a series of proteins important for inflammation and the immune response). Covered in this practice are immunotoxicity and biocompatibility tests as well as immunologic tests, which shall be performed to determine the suitability of a material to be used in medical devices. The tests shall conform to the requirements specified.1.1 This practice covers the introduction of foreign materials into the body that may have an impact on the immune system. One possible effect is that the immune system will be depressed or certain cell types may be affected. Immunotoxicity may be determined with blood and tissue samples from the animals used in the other biocompatibility test procedures such as implantation and blood contact test protocols. It is also possible to use these techniques with blood samples from human patients in a clinical trial. Any procedures with human subjects should follow the appropriate rules of the local institutional review board and the appropriate regulatory agencies. This document may serve as an annex to Practice F748.1.2 The material may affect the humoral immune response, the cell mediated response, or both.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

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