定价： 481元 / 折扣价： 409 元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车

4.1 This practice describes and defines factors to be taken into consideration when designing and fabricating a cleanroom or controlled area that is used for aerospace operations and fabrication. Following the suggestions herein should provide a facility that is more capable of meeting performance requirements and that will offer protection against contamination for objects fabricated and processed in such a facility.1.1 The purpose of this practice is to provide design and construction guidelines for contamination controlled facilities used in the assembly and integration of aerospace hardware. The guidelines herein are intended to ensure that the facilities, when used properly, will meet the cleanliness requirements of aerospace hardware and processes. The objective is to limit contamination due to the deposition of particulate and molecular contaminants on flight hardware surfaces.1.2 One cleanliness classification of a facility is the airborne particle concentrations in accordance with ISO 14644-1 and 14644-2. Airborne particle concentrations in accordance with FED-STD-209E are included for reference. This simple classification is inadequate to describe a facility that will support the assembly and integration of spacecraft. The extended duration of hardware exposure during fabrication and testing, the sensitivity of the hardware to hydrocarbons and other molecular contaminants, and the changing requirements during assembly and integration must be considered in addition to the airborne particle concentrations.1.3 The guidelines specified herein are intended to provide facilities that will effectively restrict contaminants from entering the facility, limit contamination generated by and within the facility, and continuously remove airborne contaminants generated during normal operations. Some items of support hardware, such as lifting equipment, stands, and shoe cleaners, are addressed since these items are often purchased and installed with the facility and may require accommodation in the design of the facility.1.4 Active filtration of molecular contaminants (such as hydrocarbons, silicones, and other chemicals) is discussed. Such active filtration of molecular contaminants may be required for the processing of highly sensitive optical devices, especially infrared and cryogenic sensors. Control of microbiological contamination is not included although HEPA (High Efficiency Particulate Air) filtration will provide some control of airborne bacteria, spores, and other viable contaminants that are typically carried on particles of sizes 0.3 μm and larger. Control of radioactive contamination and accommodation of very hazardous materials such as propellants, strong acids or caustics, or carcinogens are not addressed.1.5 No facility will compensate for excessive contamination generated inside the facility. In addition to an effective facility design, the user must also institute a routine maintenance program (see Practice E2042) for the facility, and personnel and operational disciplines that limit the transfer of contaminants through entry doors and contaminant generation inside the facility.1.6 This practice only addresses guidelines for contamination control in facility design. It must be implemented in compliance with all mandatory government and regulatory building and safety codes. References to related cleanroom standards and U.S. building codes and standards may be found in IEST-RP-CC012.1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.7.1 The values given in parentheses are provided for information only and are not considered standard.1.8 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.1.9 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： 646元 / 折扣价： 550 元 加购物车

5.1 The primary purpose of this practice is to describe a procedure for collecting near real-time data on airborne particle concentration and size distribution in clean areas as indicated by single particle counting techniques. Implementation of some government and industry specifications requires acquisition of particle size and concentration data using an SPC.5.2 The processing requirements of many products manufactured in a clean room involves environmental cleanliness levels so low that a single particle counter with capability for detecting very small particles is required to characterize clean room air. Real-time information on concentration of airborne particles in size ranges from less than 0.1 μm to 5 μm and greater can be obtained only with an SPC. Definition of particles larger than approximately 0.05 μm may be carried out with direct measurement of light scattering from individual particles; other techniques may be required for smaller particles, such as preliminary growth by condensation before particle measurement.5.3 Particle size data are referenced to the particle system used to calibrate the SPC. Differences in detection, electronic and sample handling systems among the various SPCs may contribute to differences in particle characterization. Care must be exercised in attempting to compare data from particles that vary significantly in composition or shape from the calibration base material. Variations may also occur between instruments using similar particle sensing systems with different operating parameters. These effects should be recognized and minimized by using standard methods for SPC calibration and operation.5.4 In applying this practice, the fundamental assumption is made that the particles in the sample passing through the SPC are representative of the particles in the entire dust-controlled area being analyzed. Care is required that good sampling procedures are used and that no artifacts are produced at any point in the sample handling and analysis process; these precautions are necessary both in verification and in operation of the SPC.1.1 This practice covers the determination of the particle concentration, by number, and the size distribution of airborne particles in dust-controlled areas and clean rooms, for particles in the size range of approximately 0.01 to 5.0 μm. Particle concentrations not exceeding 3.5 × 106 particles/m 3 (100 000/ft3) are covered for all particles equal to and larger than the minimum size measured.1.2 This practice uses an airborne single particle counting device (SPC) whose operation is based on measuring the signal produced by an individual particle passing through the sensing zone. The signal must be directly or indirectly related to particle size.NOTE 1: The SPC type is not specified here. The SPC can be a conventional optical particle counter (OPC), an aerodynamic particle sizer, a condensation nucleus counter (CNC) operating in conjunction with a diffusion battery or differential mobility analyzer, or any other device capable of counting and sizing single particles in the size range of concern and of sampling in a cleanroom environment.1.3 Individuals performing tests in accordance with this practice shall be trained in use of the SPC and shall understand its operation.1.4 Since the concentration and the particle size distribution of airborne particles are subject to continuous variations, the choice of sampling probe configuration, locations, and sampling times will affect sampling results. Further, the differences in the physical measurement, electronic, and sample handling systems between the various SPCs and the differences in physical properties of the various particles being measured can contribute to variations in the test results. These differences should be recognized and minimized by using a standard method of primary calibration and by minimizing variability of sample acquisition procedures.1.5 Sample acquisition procedures and equipment may be selected for specific applications based on varying cleanroom class levels. Firm requirements for these selections are beyond the scope of this practice; however, sampling practices shall be stated that take into account potential spatial and statistical variations of suspended particles in clean rooms.NOTE 2: General references to cleanroom classifications follow Federal Standard 209E, latest revision. Where airborne particles are to be characterized in dust-controlled areas that do not meet these classifications, the latest revision of the pertinent specification for these areas shall be used.1.6 Units—The values stated in SI units are to be regarded as 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. For specific hazards statements, see Section 8.1.8 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.

定价： 590元 / 折扣价： 502 元 加购物车

1.1 This guide is intended to assist the maintenance engineer in the preparation of a specification or work instruction for re-coating items that are presently coated with what is known within the nuclear power industry as an "unqualified coating."

定价： 0元 / 折扣价： 0 元

This test method covers the apparatuses required, sampling methods, standard procedures and calculations, and test reports for counting and sizing airborne microparticulate matter, the sampling areas for which are specifically those with contamination levels typical of cleanrooms and dust-controlled areas. The test method is based on the microscopical examination of particles impinged upon a membrane filter with the aid of a vacuum. Sampling may be done in a cleanroom, clean zone, or other controlle areas, or in a duct or pipe, wherein the number of sampling points is proportional to the floor area of the enclosure to be checked. The apparatus and facilities required are typical of a laboratory for the study of macroparticle contamination. The operator must have adequate basic training in microscopy and the techniques of particle sizing and counting.1.1 This test method covers counting and sizing airborne particulate matter 5 µm and larger (macroparticles). The sampling areas are specifically those with contamination levels typical of cleanrooms and dust-controlled areas.1.2 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.1.3 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 prescribes the standard nominal diameters and cross-sectional areas of American Wire Gage (AWG) sizes of solid round wires, used as electrical conductors, and gives equations and rules for the calculation of standard nominal mass and lengths, resistances, and breaking or rated strengths of such wires. All wire dimensions and properties shall be considered as occurring at the internationally standardized reference temperature and all calculations shall be rounded in the final value only.1.1 This specification prescribes standard nominal diameters and cross-sectional areas of American Wire Gage (AWG) sizes of solid round wires, used as electrical conductors, and gives equations and rules for the calculation of standard nominal mass and lengths, resistances, and breaking strengths of such wires (Explanatory Note 1).1.2 The values stated in inch-pound or SI units are to be regarded separately as standard. Each system shall be used independently of the other. Combining values of the two systems may result in nonconformance with the specification. For conductor sizes designated by AWG or kcmil sizes, the requirements in SI units have been numerically converted from the corresponding values stated or derived, in inch-pound units. For conductor sizes designated by SI units only, the requirements are stated or derived in SI units.1.2.1 For density, resistivity and temperature, the values stated in SI units are to be regarded as standard.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： 590元 / 折扣价： 502 元 加购物车

4.1 This practice is not meant to include products other than exit devices except to the extent that such products directly relate to the use of exit devices. When other products are described, the security attributes of the other products are described generally in the documents referenced in Section 2.1.1 This practice provides information for the installation of exit devices used in areas of security to achieve the greatest security possible without violating the requirements and spirit of NFPA 101.1.2 Security of a high level is not always possible with these products but the use of certain types and functions of exit devices will afford a much higher degree of security than the use of other types and functions.1.3 The values as stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

定价： 515元 / 折扣价： 438 元 加购物车

3.1 Fireclay steel-teeming nozzles and sleeves are classified by volume reheat change. Bloating of some refractories results in irregular reheat dimensions, which are difficult to measure. This practice determines the volume without depending upon physical linear measurements.3.2 Blast furnace checkers that have irregular cross-sections are classified by “creep properties.” This practice determines the average cross-sectional area.1.1 This practice covers the methods of calculating areas, volumes, and linear changes of irregularly shaped refractory specimens.1.2 The specimens must have a constant cross-sectional area over a length (L).1.3 The values stated in SI units are to be regarded as the standard.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 / 折扣价： 438 元 加购物车

5.1 This specification sets forth minimum standard requirements for use in local codes and ordinances relating to public, multi-family, residential, and commercial outdoor play areas or zones and their environments.5.2 This specification does not have the effect of law, nor is it intended to supersede local codes and ordinances of a more restrictive nature.5.3 Playgrounds that intentionally incorporate water into the play area are exempt from this specification.1.1 This specification provides the recommended minimum requirements for denoting various types of fences/barriers for the protection of children's outdoor play spaces in public, commercial, and multi-family residential use locations. This specification excludes individual single family residential use play equipment locations. Interior fences located in a play area that has a perimeter fence established shall only have to comply with the latch height requirement indicated in 7.6.2.1.2 This specification provides for the safety of occupants in play areas or zones as it pertains to vehicular intrusion as well as other participant intrusion, and for children containment or entry/exit. This specification has the intent to also keep children inside a predetermined area in an effort to enhance supervision; to keep children from running out of the area into water and other hazards; to minimize the likelihood of facial lacerations on low gate and fence hardware; to minimize the likelihood of abduction; and to restrict access to railroads, highways, roads, and other such hazards.1.3 This specification does not choose the product components for the fence system, the choice of which should be made by the operators of the play space and their specification writers or drafters based upon their determination of the merits of the products that could be used.1.4 The values stated in inch-pound units are to be regarded as standard. The SI values given in parentheses are for information only.1.5 This specification does not purport to address the aspect of safety within a play area or zone. It is the responsibility of the user of this specification to establish appropriate safety practices as related to the play area and determine the applicability of regulatory requirements 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.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 This practice addresses AML PAs, PUs, Keyword Features, and Project Sites. This practice is significant as it provides for uniformity of geospatial data pertaining to the geographic location and description of AML sites located throughout the United States.4.2 This geospatial data standard will help ensure uniformity of data contributed by each RA and assist organizations in efforts to create, utilize, and share geospatial data. Use of this standard will result in organized and accessible data to support programmatic decisions and work plan development, increased awareness of AML problems, and better communication between RA, the public, industry, and other interested parties.4.3 The geospatial data may be served as a layer in a national dataset and map service.1.1 This practice covers the minimum elements for the accurate location and description of geospatial data for defining Abandoned Mine Land (AML) Problem Areas, Planning Units, Keyword Features, and Project Sites as originally defined by the Office of Surface Mining Reclamation and Enforcement (OSMRE), through its Abandoned Mine Land Inventory Manual (Directive AML-1) under the jurisdiction of Surface Mining Control and Reclamation Act of 1977. These standards remain applicable to mining organizations that geospatially locate and identify AML sites, however these standards can be used for entities that are in beginning phases of mapping and identifying AML sites using protocol that is consistent with existing nomenclature.1.1.1 Abandoned mine lands consist of those lands and waters which were mined for coal or other minerals, or both, and abandoned or left in an inadequate condition of reclamation and for which there is no continuing reclamation responsibility for mitigation of adverse impacts to human health and safety or environmental resources.1.1.2 As used in this practice, an AML Problem Area (PA) represents a closed polygon boundary for a uniquely defined geographic area contained within an AML Planning Unit (PU). An AML PA is a subdivision of an AML PU that contains one or more AML keyword features together with impacted land or water resources or both. An AML PA should not cross PU boundaries.1.1.3 As used in this practice, an AML PU represents a closed polygon boundary of a uniquely defined geographic area identified by unique numbers and names. An entire WCU may be delineated as a single PU or subdivided into multiple PUs.1.1.4 As used in this practice, an AML Keyword Feature is a point, line, or polygon defining the location of a specific on-the-ground feature contained within an AML Problem Area (PA) as described in the AML Inventory Manual.1.1.5 As used in this practice, an AML Project Site is a closed polygon boundary for a uniquely defined geographic area that includes the area disturbed to achieve the reclamation. An AML Project Site may contain one or more AML keyword features together with impacted land or water resources or both.1.2 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 may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the 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 practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project’s many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.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： 702元 / 折扣价： 597 元 加购物车

定价： 481元 / 折扣价： 409 元 加购物车

4.1 A supply well provides groundwater for household, domestic, commercial, agricultural, or industrial uses.4.2 Using a standardized protocol based on an existing industry standard or approved regulatory methods and procedures to collect water samples from a supply well is essential to obtain representative water quality data. These data can be critical to efforts to protect water uses, and human health, and identify changes when they occur. Use of this guide will help the project team to design and execute an effective water supply sampling program.4.3 It is important to understand the objectives of the sampling program before designing it. Water supplies may be sampled for various reasons including any or all of the following:(1) baseline sampling before an operation of concern,(2) periodic sampling during such an operation,(3) investigative responses to perceived changes in water quality, or(4) ongoing monitoring related to known or potential groundwater constituents of concern in the area.Sampling programs should be based on these objectives and be developed in coordination with the prospective laboratory(ies) to ensure its procedures, capabilities, and limitations meet the needs of the program, protect human health and fulfill regulatory requirements.1.1 This guide presents a methodology for obtaining representative groundwater samples from domestic or commercial water wells that are in proximity to oil and gas exploration and production (E&P) operations. E&P operations include, but are not necessarily limited to, site preparation, drilling, completion, and well stimulation (including hydraulic fracturing), and production activities. The goal is to obtain representative groundwater samples from domestic or commercial water wells that can be used to identify the baseline groundwater quality and any subsequent changes that may be identified. While this guide focuses on baseline sampling in conjunction with oil and gas E&P activities, the principles and practices recommended are based on well-established methods that have been in use for many years in other industrial situations. This guide recommends sampling and analytical testing procedures that can identify various chemical species present including metals, dissolved gases (such as methane), hydrocarbons (and other organic compounds), as well as overall water quality.1.2 This guide provides information on typical residential and commercial water supply well systems and guidance on developing and implementing a sampling program, including determining sampling locations, suggested purging techniques, selection of potential analyses and laboratory certifications, data management, and integrity. It also includes guidance on personal safety. The information included pertains to baseline sampling before beginning any activities that could present potential risks to local aquifers, periodic sampling during and after such work, and ongoing monitoring relating to known or potential groundwater constituents in the area. This guide does not address policy issues related to frequency or timing of sampling or sampling distances from the wellhead. In addition, it does not address reporting limits, sample preservation, holding times, laboratory quality control, regulatory action levels, or interpretation of analytical results.1.3 These guidelines are not intended to replace or supersede regulatory requirements and technical methodology or guidance nor are these guidelines intended for inclusion by reference in regulations. Instances where this guide is in conflict with statutory or regulatory requirements, practitioners shall defer to the latter. These guidelines are intended to assist in developing sampling programs to meet project goals and objectives. However, site-specific conditions, regulatory requirements, site-specific health and safety issues, technical manuals and directives, and program data quality objectives should be evaluated and consulted along with the information contained in this guide for each individual site and sampling program.1.4 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project’s many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.1.5 Users are responsible for investigating and identifying all the legal and regulatory requirements that are applicable for the location where the sampling is being performed.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 and health practices and determine the applicability of regulatory limitations prior to use.

定价： 590元 / 折扣价： 502 元 加购物车

3.1 This practice is a prescriptive set of installation methods to be used for suspended ceilings and is often used in lieu of designing a separate lateral restraint system. The authority having jurisdiction shall determine the applicability of this practice to local code requirements.3.2 This practice covers installation of suspended ceiling systems and related components in areas that require resistance to the effects of earthquake motions as defined by ASCE 7 and the International Building Code.3.3 The practice is broken into two main sections. The first section covers areas with light to moderate earthquake potential (Seismic Design Category C) while the second deals with severe earthquake potential (Seismic Design Category D, E & F).3.4 This practice includes requirements from multiple sources including previous versions of this practice, CISCA Seismic Recommendations for Direct-hung Acoustical Tile and Lay-in Ceilings, Seismic Zones 0-2 and CISCA Guidelines for Seismic Restraint for Direct Hung Suspended Ceiling Assemblies, Seismic Zones 3 & 4, suspended ceiling requirements from the International Building Code and ASCE 7. The purpose is to combine the requirements from these sources into a single comprehensive document.AbstractThis practice covers acoustical ceiling suspension systems and their additional requirements for application in areas subject to light to moderate seismic disturbance such as Uniform Building Code Seismic Zone 2, the BOCA Basic National Building Code where Av is less than 0.20 but greater than 0.10, and the Standard Building Code (SBC) where Av is less than 0.20 but greater than 0.05. This practice also covers areas subject to moderate to severe seismic disturbance such as Uniform Building Code Seismic Zones 3 and 4, the BOCA Basic National Building Code where Av is greater than 0.20, and the SBC where Av is greater than 0.20. The application of this practice is to be determined by local authorities. Current seismic maps published by recognized authorities such as those previously mentioned, as well as related material such as Open File 82-1033 and MS-812 Seismicity Maps, should be consulted. This practice is not intended to stifle research and development of new products or methods which may simplify the application method specified herein. A variation, however, must be substantiated by verifiable engineering data. A ceiling area of 144 ft2 [13m2] or less, surrounded by walls that connect directly to the structure above shall be exempt from this practice.1.1 This practice covers the installation of suspended systems for acoustical tile and lay-in panels and their additional requirements for two groups of buildings that are constructed to resist the effects of earthquake motions as defined by ASCE 7 and the International Building Code. These groupings are for Seismic Design Category C and Seismic Design Categories D, E and F.1.2 The authority having jurisdiction shall determine the applicability of this practice.1.3 Test Methods E3090/E3090M, Specification C635, and Practice C636 cover suspension systems, their installation, and testing without special regard to seismic lateral restraint needs. They remain applicable and shall be followed when this practice is specified.1.4 Ceilings less than or equal to 144 ft2 [13.4 m2] and surrounded by walls connected to the structure above are exempt from the requirements of this practice.1.5 This practice is not intended to stifle research and development of new products or methods. This practice is not intended to prevent the installation of any material or prohibit any design or method of construction not prescribed in this practice, provided that any such alternative has been substantiated by verifiable engineering data or full-scale dynamic testing that is acceptable to the authority having jurisdiction.1.6 Ceiling areas of 1000 ft2 [92.9 m2] or less shall be exempt from the lateral force bracing requirements of 5.2.8.1.7 Ceilings constructed of gypsum board which is screw or nail attached to suspended members that support a ceiling on one level extending from wall to wall shall be exempt from the requirements of this practice.1.8 Free floating ceilings (those not attached directly to any structural walls) supported by chains or cables from the structure are not required to satisfy the seismic force requirements provided they meet the following requirements:1.8.1 The design load for such items shall equal 1.4 times the vertical operating weight.1.8.2 Seismic interaction effects shall be considered in accordance with 5.7.1.8.3 The connection to the structure shall allow a 360° range of motion in the horizontal plane.1.9 The values stated in either inch-pound or SI units are to be regarded as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems result in nonconformance with the specification.1.10 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.1.11 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： 646元 / 折扣价： 550 元 加购物车

1.1 This specification applies to air ventilating grille units for detention areas, assembled in part from materials conforming to Specifications A627, A628, and A629. 1.2 The assemblies described herein are intended to provide two types of security, designated Type A and Type B. 1.2.1 Type A -A ventilation unit, utilizing homogeneous TR steel bars for the principal security component. 1.2.2 Type B -A ventilation unit utilizing perforated tool-resisting steel plate for the principal security component. 1.3 It is presumed that equipment manufacturers will fabricate and assemble the materials so as not to impair the performance characteristics specified in the applicable material specifications. 1.4 The descriptions herein of certain assemblies are not intended to infer that other assemblies cannot be used to obtain similar results.

定价： 0元 / 折扣价： 0 元