30多年来，Chentrol产品设置的塑料阀门的结构和材料标准称为这个行业的标准。选型工程师应该了解下列内容：
　　For over 30 years, the construction and performance standards on plastic valves have traditionally been set by Chemtrol products for the industry to follow. Specifying engineers should know that:

1. Chemtrol阀门100%经过阀座和外壳泄漏检测。
   Chemtrol valves are 100% tested for both seat and shell leaks.
2. PVC和CPVC材质Chemtrol阀门的承插端口符合ASTM标准D-2467 (PVC)和F-439 (CPVC)的尺寸要求，适用于目录80承插压力连接件。关于Chemtrol阀门的坚固的目录80类型承插和螺纹连接端口的尺寸细节，请参阅第31页的“工程技术参数”。
   The sockets of PVC and CPVC Chemtrol valves conform to the dimensional requirements of ASTM Standards D-2467 (PVC) and F-439 (CPVC) for Schedule 80 Socket pressure fittings. For dimensional details of the rugged Schedule 80 type socket and thread end connections of Chemtrol valves, see Engineering Data, page 31.
3. 所有Chemtrol阀门的螺纹连接端口符合ANSI B1.20.1(以前为ASAB2.1)标准中美国锥管螺纹的要求，符合ASTM标准D-2464 (PVC)和F-437 (CPVC)适用于目录80螺纹压力连接件的尺寸要求。
   The threaded end connections of all Chemtrol valves meet ANSI B1.20.1 (was ASA B2.1) requirements for American Taper Pipe Threads and conform to the dimensional requirements of ASTM Standards D-2464 (PVC) and F-437 (CPVC) for Schedule 80 Threaded pressure fittings.
4. 适用于所有Chemtrol阀门的法兰符合ANSI B16.5适用于150磅级钢管法兰标准有关外径和螺栓孔的要求。
   The flanges attached to all Chemtrol valves meet the outside diameter and bolt hole requirements of ANSI B16.5 for 150 lb. Steel Pipe Flanges.
5. PVC和CPVC的物理和化学性能，被ASTM标准D-1784归类为特性材料。这种材料，用在国内生产的Chemtrol阀门上，超过了为单元类别12454-B (PVC)和23447-B (CPVC)设置的最严格的要求。这些被规定在管道上使用的各种材料，其优点在于最高的流体静力设计应力额定值(2000 psi)和最好的耐腐蚀性能。
   The physical and chemical properties of PVC and CPVC are classified and grouped into characteristic materials by ASTM Standard D-1784. The materials, used in domestically produced Chemtrol Valves, exceed the rigid requirements set forth for cell class 12454-B (PVC) and 23447-B (CPVC). These are the respective materials stipulated for use in pipes which merit the highest Hydrostatic Design Stress rating (2000 psi) and the maximum corrosion resistance.
6. 所有PVC和CPVC材质的Chemtrol阀门都经过美国国家卫生基金会(NSF)的认证。这个独立的第三方认证机构保证这些产品和材料经过正式的检测，符合ASTM和ANSI标准。从公共卫生的利益出发，为了更加安全的传输饮用水，这个机构进一步检验证实所认证的产品符合NSF标准14，“塑料管道系统部件和相关材料”的化学/味道、气味和毒性方面的要求。
   All PVC and CPVC Chemtrol Valves are listed by the National Sanitation Foundation (NSF). This independent third party certifier provides assurance that products and materials are regularly tested to comply with ASTM and ANSI Standards. In the interest of public health, the agency further verifies that the listed products conform to the chemical/taste, odor, and toxicological requirements of NSF Standard 14, “Plastic Piping System Components and Related Materials,” in order to safely convey potable water.

　　为了有助于产品设计，所有Chemtrol阀门都有公布流体流量系数(Cv值)。Cv所定义的流量，单位为加仑/公升，当温度为15^oC时， 通过一个阀门时将产生1.0 PSI的压降。
　　As an aid to system design, fluid flow coefficients (Cv values) are shown for all Chemtrol valves. Cv is defined as the flow, in GPM, through a valve which will produce a pressure drop of 1.0 PSI when the medium is water at 60^oF.
　　为了确定在给定条件下的压降，下列公式可能有用：
　　To determine the pressure drop for a given condition, the following formula may be used:

　　下列一个问题的解法。参阅产品规格说明页中指定阀门的Cv值。
　　The solution of an example problem follows. Refer to the product description page in this Valve Guide for Cv values of specific valves.

例子
Example

　　求通过DN40通径PVC球形止回阀的压降，水流量为50 gpm.
　　Find the pressure drop across a 1 1/2" PVC Ball Check Valve with a water flow rate of 50 gpm.
　　如这个“阀门指南”中的第15页所示，Chemtrol止回阀的Cv值为56，
　　The Cv for the Chemtrol Check Valve is 56, as shown on page 15 of this Valve Guide.