定价： 1290元 / 折扣价： 1149 元 加购物车

定价： 1656元 / 折扣价： 1474 元 加购物车

定价： 916元 / 折扣价： 816 元 加购物车

定价： 1132元 / 折扣价： 1008 元 加购物车

定价： 1840元 / 折扣价： 1638 元 加购物车

定价： 541元 / 折扣价： 482 元 加购物车

定价： 1840元 / 折扣价： 1638 元 加购物车

定价： 541元 / 折扣价： 482 元 加购物车

定价： 1840元 / 折扣价： 1638 元 加购物车

定价： 1840元 / 折扣价： 1638 元 加购物车

定价： 590元 加购物车

5.1 The increased use of geomembranes as barrier materials to restrict liquid or gas movement, and the common use of dual-track seams in joining these sheets, has created a need for a standard nondestructive test by which the quality of the seams can be assessed for continuity and watertightness. The test is not intended to provide any indication of the physical strength of the seam.5.2 This practice recommends an air pressure test within the channel created between dual-seamed tracks whereby the presence of unbonded sections or channels, voids, nonhomogenities, discontinuities, foreign objects, and the like, in the seamed region can be identified.5.3 This technique is intended for use on seams between geomembrane sheets formulated from the appropriate polymers and compounding ingredients to form a plastic or elastomer sheet material that meets all specified requirements for the end use of the product.1.1 This practice covers a nondestructive evaluation of the continuity of parallel geomembrane seams separated by an unwelded air channel. The unwelded air channel between the two distinct seamed regions is sealed and inflated with air to a predetermined pressure. Long lengths of seam can be evaluated by this practice more quickly than by other common nondestructive tests.1.2 This practice should not be used as a substitute for destructive testing. Used in conjunction with destructive testing, this method can provide additional information regarding the seams undergoing testing.1.3 This practice supercedes Practice D4437/D4437M for geomembrane seams that include an air channel. Practice D4437/D4437M may continue to be used for other types of seams. The user is referred to the referenced standards or to EPA/530/SW-91/051 for additional information regarding geomembrane seaming techniques and construction quality assurance.1.4 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.1.5 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.

定价： 515元 加购物车

This specification covers centrifugally cast cylinders with an outer layer of white cast iron and the remainder of the material of gray cast iron. These castings are suitable for pressure containing parts of the design strength of which is based on the gray iron portion of the cylinder. The white iron portion of the cylinder shall be made to a minimum hardness and the casting process shall be controlled to produce a metallurgical bond between the two metal layers. All surfaces shall be machined prior to the cylinders being placed into service. The tensile strength of the cast irons shall be measured by tension testing while the thickness of the white cast iron shall be determined by ultrasonic testing.1.1 This specification2 covers centrifugally cast cylinders with an outer layer of white cast iron and the remainder of the material of gray cast iron. These castings are suitable for pressure-containing parts, the design strength of which is based on the gray iron portion of the cylinder. These castings are suitable for service at temperatures up to 450 °F [230 °C].1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.1.3 The following safety hazards caveat pertains only to the test method portion, Section 8, of this specification: 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.

定价： 515元 加购物车

定价： 515元 加购物车

5.1 This test method provides a simple means of characterizing the thermomechanical behavior of plastic compositions using a very small amount of material. Since small test specimen geometries are used, it is essential that the specimens be representative of the material being tested. The data obtained can be used for quality control and/or research and development purposes. For some classes of materials, such as thermosets, it can also be used to establish optimum processing conditions.5.2 Dynamic mechanical testing provides a sensitive means for determining thermomechanical characteristics by measuring the elastic and loss moduli as a function of frequency, temperature, or time. Plots of moduli and tan delta of a material versus these variables can be used to provide a graphic representation indicative of functional properties, effectiveness of cure (thermosetting-resin systems), and damping behavior under specified conditions.5.2.1 Observed data are specific to experimental conditions. Reporting in full (as described in this test method) the conditions under which the data was obtained is essential to assist users with interpreting the data an reconciling apparent or perceived discrepancies.5.3 This test method can be used to assess the following:5.3.1 The modulus as a function of temperature or aging, or both,5.3.2 The modulus as a function of frequency,5.3.3 The effects of processing treatment, including orientation, induced stress, and degradation of physical and chemical structure,5.3.4 Relative resin behavioral properties, including cure and damping,5.3.5 The effects of substrate types and orientation (fabrication) on elastic modulus,5.3.6 The effects of formulation additives that might affect processability or performance,5.3.7 The effects of annealing on modulus and glass transition temperature,5.3.8 The effect of aspect ratio on the modulus of fiber reinforcements, and5.3.9 The effect of fillers, additives on modulus and glass transition temperature.5.4 Before proceeding with this test method, refer to the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters, or combination thereof, covered in the relevant ASTM material specification shall take precedence over those mentioned in this test method. If there are no relevant ASTM material specifications, then the default conditions apply.1.1 This test method outlines the use of dynamic mechanical instrumentation for determining and reporting the viscoelastic properties of thermoplastic and thermosetting resins and composite systems in the form of rectangular bars molded directly or cut from sheets, plates, or molded shapes. The elastic modulus data generated is used to identify the thermomechanical properties of a plastics material or composition.1.2 This test method is intended to provide a means for determining the viscoelastic properties of a wide variety of plastics using nonresonant, forced-vibration techniques as outlined in Practice D4065. In particular, this method identifies the procedures used to measure properties using what is known as a dual-cantilever beam flexure arrangement. Plots of the elastic (storage) modulus, loss (viscous) modulus, and complex modulus, and tan delta as a function of frequency, time, or temperature are indicative of significant transitions in the thermomechanical performance of the polymeric material systems.1.3 This test method is valid for a wide range of frequencies, typically from 0.01 Hz to 100 Hz.1.4 Test data obtained by this test method are relevant and appropriate for use in engineering design.1.5 The values stated in SI units are to be regarded as standard.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.NOTE 1: There is no known ISO equivalent to this standard.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.

定价： 515元 加购物车