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5.1 This practice is intended for the semi-automated or automated ultrasonic examination of electrofusion joints used in the construction and maintenance of polyethylene piping systems.5.2 Polyethylene piping has been used instead of steel alloys in the petrochemical, power, water, gas distribution, and mining industries due to its reliability and resistance to corrosion and erosion.5.3 The joining process can be subject to a variety of flaws including, but not limited to: lack of fusion, cold fusion, particulate contamination, inclusions, short stab depth, and voids.5.4 Polyethylene material can have a range of acoustic characteristics that make electrofusion joint examination difficult. Polyethylene materials are highly attenuative, which often limits the use of higher ultrasonic frequencies. It also exhibits a natural high frequency filtering effect. An example of the range of acoustic characteristics is provided in Table 1.6 The table notes the wide range of acoustic velocities reported in the literature. This makes it essential that the reference blocks are made from pipe grade polyethylene with the same density cell class as the electrofusion fitting examined.(A) A range of velocity and attenuation values have been noted in the literature (1-9).5.5 Polyethylene is reported to have a shear velocity of 987 m/s. However, due to extremely high attenuation in shear mode (on the order of 5 dB/mm (127 dB/in.) at 2 MHz) no practical examinations can be carried out using shear mode (6).5.6 Due to the wide range of applications, joint acceptance criteria for polyethylene pipe are usually project-specific.5.7 A cross-sectional view of a typical joint between polyethylene pipe and an electrofusion coupling is illustrated in Fig. 1.FIG. 1 Typical Cross-Sectional View of an Electrofusion Coupling Joint1.1 This practice covers procedures for phased array ultrasonic testing (PAUT) of electrofusion joints in polyethylene pipe systems. Although high density polyethylene (HDPE) and medium density polyethylene (MDPE) materials are most commonly used, the procedures described may apply to other types of polyethylene.NOTE 1: The notes in this practice are for information only and shall not be considered part of this practice.NOTE 2: This standard references HDPE and MDPE for pipe applications defined by Specification D3350.1.2 This practice does not address ultrasonic examination of butt fusions. Ultrasonic testing of polyethylene butt fusion joints is addressed in Practice E3044/E3044M.1.3 Phased array ultrasonic testing (PAUT) of polyethylene electrofusion joints uses longitudinal waves introduced by an array probe mounted on a zero degree wedge. This practice is intended to be used on polyethylene electrofusion couplings for use on polyethylene pipe ranging in diameters from nominal 4 in. to 28 in. (100 mm to 710 mm) and for coupling wall thicknesses from 0.3 in. to 2 in. (8 mm to 50 mm). Greater and lesser thicknesses and diameters may be tested using this standard practice if the technique can be demonstrated to provide adequate detection on mockups of the same geometry.1.4 This practice does not specify acceptance criteria.1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.6 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.1.7 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 This practice describes procedures applicable to both shop and field conditions. More comprehensive or precise measurements of the characteristics of complete systems and their components will generally require laboratory techniques and electronic equipment such as oscilloscopes and signal generators. Substitution of these methods is not precluded where appropriate; however, their usage is not within the scope of this practice.5.2 This document does not establish system acceptance limits, nor is it intended as a comprehensive equipment specification.5.3 While several important characteristics are included, others of possible significance in some applications are not covered.5.4 Since the parameters to be evaluated and the applicable test conditions must be specified, this practice shall be prescribed only by those familiar with ultrasonic NDT technology and the required tests shall be performed either by such a qualified person or under his supervision.5.5 Implementation may require more detailed procedural instructions in the format of the using facility.5.6 In the case of evaluation of a complete system, selection of the specific tests to be made should be done cautiously; if the related parameters are not critical in the intended application, then their inclusion may be unjustified. For example, vertical linearity may be irrelevant for a go/no-go test with a flaw gate alarm, while horizontal linearity might be required only for accurate flaw-depth or thickness measurement from the display screen.5.7 No frequency of system evaluation or calibration is recommended or implied. This is the prerogative of the using parties and is dependent on application, environment, and stability of equipment.5.8 Certain sections are applicable only to instruments having receiver gain controls calibrated in decibels (dB). While these may sometimes be designated “gain,” “attenuator,” or “sensitivity” on various instruments, the term “gain controls” will be used in this practice in referring to those which specifically control instrument receiver gain but not including reject, electronic distance-amplitude compensation, or automatic gain control.5.9 These procedures can generally be applied to any combination of instrument and search unit of the commonly used types and frequencies, and to most straight-beam examination, either contact or immersed. Certain sections are also compatible with angle-beam, wheel, delay-line, and dual-search unit techniques. Their use, however, should be mutually agreed upon and so identified in the test report.5.10 The validity of the results obtained will depend on the precision of the instrument display readings. This is assumed to be ±0.04 in. (±1 mm), yielding between 1 % and 2 % of full scale (fs) readability for available instrumentation having suitable screen graticules and display sharpness.1.1 This practice describes procedures for evaluating the following performance characteristics of ultrasonic pulse-echo examination instruments and systems: Horizontal Limit and Linearity; Vertical Limit and Linearity; Resolution - Entry Surface and Far Surface; Sensitivity and Noise; Accuracy of Calibrated Gain Controls. Evaluation of these characteristics is intended to be used for comparing instruments and systems or, by periodic repetition, for detecting long-term changes in the characteristics of a given instrument or system that may be indicative of impending failure, and which, if beyond certain limits, will require corrective maintenance. Instrument characteristics measured in accordance with this practice are expressed in terms that relate to their potential usefulness for ultrasonic testing. Instrument characteristics expressed in purely electronic terms may be measured as described in Guide E1324.1.2 Ultrasonic examination systems using pulsed-wave trains and A-scan presentation (rf or video) may be evaluated.1.3 The procedures are applicable to shop or field conditions; additional electronic measurement instrumentation is not required.1.4 This practice establishes no performance limits for examination systems; if such acceptance criteria are required, these must be specified by the using parties. Where acceptance criteria are implied herein, they are for example only and are subject to more or less restrictive limits imposed by customer's and end user's controlling documents.1.5 The specific parameters to be evaluated, conditions and frequency of test, and report data required must also be determined by the user.1.6 This practice may be used for the evaluation of a complete examination system, including search unit, instrument, interconnections, fixtures and connected alarm and auxiliary devices, primarily in cases where such a system is used repetitively without change or substitution. This practice is not intended to be used as a substitute for calibration or standardization of an instrument or system to inspect any given material. There are limitations to the use of standard reference blocks for that purpose.21.7 Required test apparatus includes selected test blocks and a precision external attenuator (where specified) in addition to the instrument or system to be evaluated.1.8 Precautions relating to the applicability of the procedures and interpretation of the results are included.1.9 Alternate procedures, such as examples described in this document, or others, may only be used with customer approval.1.10 Units—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.1.11 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.1.12 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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定价: 590元 / 折扣价: 502 加购物车

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5.1 This practice is intended to provide standardized procedures for evaluating linear phased-array ultrasonic probes. It is not intended to define performance and acceptance criteria, but rather to provide data from which such criteria may be established.5.2 Implementation may require more detailed procedural instructions in a format of the using facility.5.3 The measurement data obtained may be employed by users of this guide to specify, describe, or provide performance criteria for procurement and quality assurance, or service evaluation of the operating characteristics of linear phased-array ultrasonic probes. All or portions of the standard practice may be used as determined by the user.5.4 The measurements are made primarily under pulse-echo conditions. To determine the relative performance of a probe element as either a transmitter or a receiver may require additional tests.5.5 While these procedures relate to many of the significant parameters, others that may be important in specific applications may not be treated. These might include power handling capability, breakdown voltage, wear properties of contact units, radio-frequency interference, and the like.5.6 Care must be taken to ensure that comparable measurements are made and that users of the standard practice follow similar procedures. The conditions specified or selected (if optional) may affect the test results and lead to apparent differences.5.7 Interpretation of some test results, such as the shape of the frequency response curve, may be subjective. Small irregularities may be significant. Interpretation of the test results is beyond the scope of this practice.5.8 Certain results obtained using the procedures outlined may differ from measurements made with phased-array ultrasonic test instruments. These differences may be attributed to differences in the nature of the experiment or the electrical characteristics of the instrumentation.5.9 The pulse generator used to obtain the frequency response and time response of the probe must have a rise time, duration, and spectral content sufficient to excite the probe over its full bandwidth, otherwise time distortion and erroneous results may result.1.1 This practice covers measurement procedures for evaluating certain characteristics of phased-array ultrasonic probes that are used with phased-array ultrasonic examination instrumentation.1.2 This practice describes means for obtaining performance data that may be used to define the acoustic and electric responses of phased-array ultrasonic probes including contact (with or without a wedge) and immersion linear phased-array probes used for ultrasonic nondestructive testing with central frequencies ranging from 0.5 MHz to 10 MHz. Frequencies outside of this range may use the same methods but the testing equipment may vary.1.3 When ultrasonic values dependent on material are specified in this practice, they are based on carbon steel with an ultrasonic wave propagation speed of 5920 m/s (±50 m/s) for longitudinal wave modes and 3255 m/s (±30 m/s) for transverse or shear wave modes.1.4 This practice describes some of the characterization and verification procedures that can be carried out at the end stage of the manufacturing process of linear phased array probes. This practice does not describe the methods or acceptance criteria used to verify the performance of the combined phased array ultrasonic instrument and probe system.1.5 While this practice is intended to provide standardized procedures for evaluating linear phased-array ultrasonic probes, it may, with suitable modifications, be used for evaluation of configurations other than linear; for example, 1.5D or 2D matrix array probes.1.6 Units—The values stated in SI units are to be regarded as the standard. The values given in parentheses after SI units are provided for information only and are not considered standard.1.7 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.1.8 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 The techniques described provide indirect measurement of thickness of sections of materials not exceeding temperatures of 93 °C [200 °F]. Measurements are made from one side of the object, without requiring access to the rear surface.5.2 Ultrasonic thickness measurements are used extensively on basic shapes and products of many materials, on precision machined parts, and to determine wall thinning in process equipment caused by corrosion and erosion.5.3 Recommendations for determining the capabilities and limitations of ultrasonic thickness gages for specific applications can be found in the cited references.7,81.1 This practice2 provides guidelines for measuring the thickness of materials using the contact pulse-echo method at temperatures not to exceed 93 °C [200 °F].1.2 This practice is applicable to any material in which ultrasonic waves will propagate at a constant velocity throughout the part, and from which back wall reflections can be obtained and resolved.1.3 This practice is primarily for flat components with parallel surfaces and has limited applicability for components with non-parallel or concentric surfaces per 1.2.1.4 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.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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