定价： 1177元 / 折扣价： 1001 元 加购物车

定价： 975元 / 折扣价： 829 元 加购物车

定价： 605元 / 折扣价： 515 元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车

定价： 0元 / 折扣价： 0 元 加购物车

定价： 0元 / 折扣价： 0 元 加购物车

定价： 0元 / 折扣价： 0 元 加购物车

5.1 Cast iron Yankee dryers can be up to 6.7 m [22 ft] in diameter, 7.3 m [24 ft] long, and weigh 91 000 Kg [100 tons], or more (refer to Fig. 1). Vessel thickness measurements are available from the paper/tissue machine operator. Cast iron is a brittle metal and has no specific yield point. Yankee dryers must maintain specific dimensional tolerances. When a pressurized Yankee or steam heated paper dryer (SHPD) remains stationary, it fills with condensate at a rapid rate. In an hour, a steam pressurized Yankee or SHPD can fill half way with condensate, doubling the weight on the frame, and the floor. Some Yankee owners have corporate requirements that a cast iron Yankee dryer remain stationary for 1/2 h, then rotation is required. Permission is required, if the Yankee is to remain stationary for more time. This issue should be discussed with the responsible person prior to the examination.FIG. 1 Yankee Dryer Drum5.2 Yankee dryers operate under a heated hood. The hood is in close proximity to the Yankee shell and allows only inches of clearance for the top half of the vessel.5.3 Cast iron steam heated paper machine dryers are 2 m [6 ft] in diameter, or more, and may be 9 m [30 ft] long.5.4 Grey cast iron experiences a continuing reduction in elastic modulus as it is stressed to increasing higher levels. It is prudent not to stress grey cast iron material beyond its operating stress level.5.5 Flaws to be found are the same as those in any cast and machined product. Attempts have been made to characterize strength properties of cast irons in compact tension tests. In a TAPPI sponsored laboratory study, two out of three cast iron compact tension specimens experienced unplanned failures. From that experience it was cautioned that cracks initiated and grew faster than expected resulting in brittle fracture before the process could be halted. The failure of these two coupons demonstrated the rate in which cracks can grow in these materials and the material’s inability to stop a crack once it begins to grow. In each case, crack advance was extremely rapid and without warning. (See Note 1.)NOTE 1: Alleveto, C., and Williams D., Acoustic Emission Evaluation of Yankee Dryer Shell Material, 1991 TAPPI Engineering Conference Proceedings, pages 475-480.5.6 Maximum Examination Pressure—Maximum Allowable Working Pressure for cast iron vessels is set based on ASME (Section VIII) pressure calculations based on thickness, radius, and material strength values, and will not exceed 10 bar [160 psi] and 230 °C [450 °F] (Specification A278/A278M). When vessels are pressurized, anomalies produce emission at pressures less than normal fill pressure. Historically, if there is damage in a cast iron pressure boundary, AE activity will begin at load/stress levels less than 50 % of operating. Defects as small as 3 mm [1/8 in.] have been found using AE, during steam pressurization to operating pressure.5.7 Pressure increments should not exceed 0.35 bar [5 psi] per minute. If pressurization medium is to be steam, the Yankee should have been through the warm-up process.5.8 Yankee dryers may receive a subsequent examination, if necessary, after the Yankee is rotated to remove any condensate present.5.9 Pressurization Schedule—Pressurization should proceed at rates that allow achieving maximum examination pressure within a 30 minute period. During pressurization, pressure holds are not necessary; however, they may be useful for reasons other than measurement of AE. Pressure hold upon achieving maximum examination pressure may be up to 30 min.5.10 Excess background noise may distort AE data or render the AE measurements useless. Users must be aware of the following common sources of background noise: (measurable flow noise); mechanical contact with the vessel by objects; electromagnetic interference (EMI) from cranes, and radio frequency interference (RFI) from nearby broadcasting facilities and from other sources; leaks at pipe or hose connections, or rain drops. This practice should not be used if background noise cannot be eliminated or controlled.5.11 Other Non-destructive test methods may be used to evaluate the significance of AE sources. Magnetic particle, ultrasonic, and radiographic examinations have been used to establish circumferential position, depth, and dimensions of flaws that produce AE. Procedures for using other NDT nethods are beyond the scope of this practice.1.1 This practice is no longer being updated but is being retained for historical value due to the procedures herein that are unique to the AE community.1.2 This practice provides guidelines for carrying out acoustic emission (AE) examinations of Yankee and Steam Heated Paper Dryers (SHPD) of the type to make tissue, paper, and paperboard products.1.3 This practice requires pressurization to levels used during normal operation. The pressurization medium may be high temperature steam, air, or gas. The dryer is also subjected to significant stresses during the heating up and cooling down periods of operation. Acoustic Emission data maybe collected during these time periods but this testing is beyond the scope of this document.1.4 The AE measurements are used to detect, as well as, localize emission sources. Other methods of nondestructive testing (NDT) may be used to further evaluate the significance of acoustic emission sources.1.5 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.1.6 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.

定价： 590元 / 折扣价： 502 元 加购物车

1.1 This test method covers the general considerations for the qualitative and quantitative determination of volatile amines such as cyclohexylamine, morpholine, and diethylaminoethanol in steam condensates and surface water by gas-liquid chromatography. 1.2 This test method may be applied to water samples containing the amines in concentrations from 2 to 15 mg/L by direct injection of alkaline aqueous samples. Higher concentrations may be determined by appropriate dilution. 1.3 Although this test method is written for flame ionization detector, the basic technology is applicable to any highly sensitive nitrogen-specific detector provided water does not interfere with the measurement. 1.4 The test method may be extended to steam condensates containing low levels of these amines by adopting suitable concentration techniques such as steam distillation to bring the analyte concentration to an accurately quantifiable range. 1.5 The test method is applicable to other chromatographable amines by appropriately varying the chromatographic parameters. This must be validated by the individual analysts. 1.6 This test method has been used successfully with reagent-grade and boiler steam condensate waters. It is the user's responsibility to assure the validity of this test method for any untested matrices. 1.7 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems 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.

定价： 0元 / 折扣价： 0 元

定价： 605元 / 折扣价： 515 元

5.1 Horizontal metal surfaces, on which water droplets tend to be retained, are more prone to rusting and corrosion than vertical or sloping surfaces. This test method is therefore more discriminating than Test Method D665 (Procedure A), since it gives a separate evaluation of the oil on a horizontal and a vertical surface. The test method indicates the ability of oils to prevent rusting and corrosion of all ferrous surfaces in steam turbines under full flow and quasi-static conditions. It is used for specification of new oils.1.1 This test method covers the ability of steam-turbine oils to prevent the rusting of horizontal and vertical ferrous surfaces when water becomes mixed with the oil.1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.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.

定价： 590元 / 折扣价： 502 元 加购物车

This specification establishes requirements for bronze castings for steam locomotive wearing parts. The following Copper Alloy UNS Nos. are specified: C93200, C93400, C93600, C93700, C93800, C94300, C94400, and C94500. The product shall be manufactured by such casting methods to produce a uniform finished product. The castings shall conform to the compositional requirements for named elements specified. The castings shall not be repaired, plugged, welded, or burned-in.1.1 This specification establishes requirements for bronze castings for steam locomotive wearing parts. The following Copper Alloy UNS Nos. are specified: C93200, C93400, C93600, C93700, C93800, C94300, C94400, C94500, and C95400.2NOTE 1: Historically, the alloys in this specification have been used in the applications listed in the Appendix. Actual practice may vary according to locomotive type and service.1.2 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.1.3 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 / 折扣价： 438 元 加购物车

1.1 This is a general method for the separation by steam distillation and the recovery of solvent and base from bituminous mixtures.1.2 The following safety hazards caveat pertains only to the test methods described in this specification. This standard does not purport to address all of the safety problems, 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.>

定价： 0元 / 折扣价： 0 元

定价： 260元 / 折扣价： 221 元

5.1 The performance and quality of steam-treated materials depends upon the surface cleanliness of the material prior to steam treatment and the adequacy of the processing. Steam treatment can be used as a decorative coating, producing a blue-gray to a blue-black appearance. It can reduce the susceptibility of ferrous PM materials to further oxidation and corrosion, thus providing better shelf life. More significantly, improvements in apparent hardness, compressive strength, wear characteristics, and some mechanical properties (see Appendix X1) can be observed due to steam treatment. The hardness of magnetite (Fe3O4) formed during steam treatment is typically equivalent to 50 HRC, and when present in sintered materials, their wear resistance can be improved significantly. Steam treatment is also used to seal parts or provide a base material for additional coatings. Steam treated ferrous PM materials are used in many industries, including automotive, marine, home appliances, and lawn and garden applications.1.1 This guide is intended as an aid in establishing and maintaining a procedure for the steam treatment, also referred to as steam blackening, of sintered ferrous PM materials and the appropriate use and evaluation of these materials. Additional information concerning the effect of this process on ferrous PM material properties is contained in Appendix X1.1.2 Units—With the exception of the values for density and the mass used to determine density, for which the use of the gram per cubic centimetre (g/cm3) and gram (g) units is the longstanding industry practice, the values 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.

定价： 515元 / 折扣价： 438 元 加购物车