美国斯毕尔公司热塑性塑料管道系统材料
Spears® Thermoplastic Piping System Materials

　　与金属不同，塑料不会生锈、生水垢或凹陷，实际上塑料使用寿命更长。与金属相比，热塑性塑料更加耐磨损，耐化学制品和腐蚀，绝缘，重量轻，而且操作上的摩擦损失更小。此外，塑料无毒、环保。除了这些优点以外，还有安装简单，维护成本低等优点，热塑性塑料管道系统部件经过多年的实践证明是无维护系统运行的选择之一。
　　Unlike metal, plastics never rust, scale, or pit - they virtually last forever. Thermoplastics are abrasion resistant, chemical and corrosion resistant, nonconductive, lightweight, and operate at lower friction-loss levels than metals. Moreover, plastics are nontoxic and environmentally safe. Adding these benefits with ease of installation at substantially lower costs, thermoplastic piping system components are the proven choice for years of maintenance free system operations.

　　美国斯毕尔公司热塑性塑料系统的连接方式
　　Joining Methods for Spears® Thermoplastic Systems

　　美国斯毕尔公司热塑性塑料管道系统产品主要部件采用PVC，CPVC或PP材料，及其各种填充玻璃纤维的改进材料。PVC和CPVC材料采用液状粘固剂很容易连接，此外，还有螺纹、法兰或机械轴节等连接方式。美国斯毕尔公司PP产品采用法兰或美国斯毕尔公司特别加固（SR）塑料内螺纹连接方式。
　　Spears® thermoplastic piping system products are designed around primary components manufactured from PVC, CPVC or PP materials and their glass filled varieties. PVC and CPVC materials can be easily joined by solvent cement welding plus threaded, flanged or mechanical coupled connections. Spears® PP products are joined by using flanged or threaded connections featuring Spears® patented Special Reinforced (SR) female plastic threads.

　　选择材料所需考虑的应用和系统结构因素
　　Material Considerations in Application and System Design

　　适当地注意应用环境和系统结构有助于保证PVC、CPVC和PP热塑性塑料管道系统部件多年的无故障运行。为了避免出现故障，对于某项应用和系统结构进行材料选择时，必须考虑下列几个问题：
　　PVC, CPVC and PP thermoplastic piping system components will give years of trouble free service with proper attention to application and system design. To avoid problems, the following key points must be considered when selecting materials for an application and in designing a system for their use.

1. 某些化学制品的流体不兼容性，特别是石油馏出物及衍生物，在不同的热塑性塑料部件内可能导致环境应力裂纹。所有阀门或系统部件的化学兼容性，包括液状粘固剂，在安装之前必须加以查证核实。流体兼容性的查证核实由用户自身负责。
   Fluid incompatibility of certain chemicals, especially petroleum distillates and derivatives, can cause environmental stress cracking in different thermoplastic components. Chemical compatibility of all valve or system components, including solvent cements, must be verified before installation. Verification of fluid compatibility is at the discretion of the user.
2. 必须考虑温度-压力关系。产品压力等级是以水介质在22^oC温度下的压力值为基础。通常，当温度增加时，产品压力等级必须降低（参阅各个阀门的温度压力表）。
   Temperature-pressure relationships must be considered. Product pressure ratings are based on use of water mediums at 73^oF. In general, product pressure ratings must be de-rated as temperature increases (see Temperature Pressure Table for individual valves).
3. 热塑性塑料系统的膨胀和收缩比金属系统更加明显。因此，系统结构设计必须为膨胀和收缩变化留有余地。建议采用美国斯毕尔公司的热塑性塑料伸缩接头。
   Expansion and contraction is greater in thermoplastic systems than in metal systems. As a result, system design must be flexible to allow for movement. Use of Spears® Thermoplastic Expansion Joints is recommended.
4. 必须避免出现可能导致内部流体冻结或超过热塑性塑料结构极限温度范围的过热或过冷环境，考虑范围还包括储存位置。
   Extreme heat or cold where internal fluids may freeze or where temperatures may exceed thermplastic design limits must be avoided, including consideration of storage locations.

5. 直接阳光暴晒会导致高热量吸收，尤其是深色热塑性塑料材料。可以涂敷白色水基乳胶涂料以减少热量累积。
   Direct sun exposure results in high thermal heat absorption, especially in darker color thermoplastic materials. A white water-based exterior latex paint can be applied to reduce heat buildup.
6. 与金属系统相比，热塑性塑料系统的抗撞击能力更低，因此在地面和地下安装时，要求避免锋利、尖锐的物体，包括安装装置和回填作业。
   Lower impact resistance of thermoplastic system components than that of metal systems requires avoidance of sharp, pointed objects in both above and below ground installations, including mounting devices and backfilling operations.
7. 正确的安装是很重要的基础。必须特别注意液状粘固剂连接、螺纹连接、法兰连接，以及阀门和其他独立系统部件安装的技术和方法说明书。系统结构还必须考虑转换到不同材料的支撑、止推基座以及其它与安装有关的因素。
   Proper installation is essential. Special attention must be given to technique and instructions for making solvent cemented connections, threaded connections, flanged connections, and for installation of valves and other individual system components. System design must also take into account support, thrust blocking, transition to different materials and other installation related factors.
8. 螺纹连接需要考虑几个问题。
   Threaded joints require several considerations.
   　　首先，螺纹系统部件的压力承受能力要比相应类型和通径的热塑性塑料管件降低50%。
   　　 First, pressure capacities of threaded system components should be de-rated to 50% of the rating for corresponding type and size of thermoplastic pipe.
   　　注意：每个阀门有各自的压力等级，不需要为其螺纹连接而降低压力等级。
   　　NOTE: Valves have individual pressure ratings and do not require de-rating for threaded connections.
   　　其次，作为内部流体，某些粘结密封剂可能会导致热塑性塑料材料出现环境应力裂纹，此外在使用之前，应该查证核实其兼容性。
   　　Second, as with internal fluids, certain paste sealants may cause environment stress cracking in thermoplastic materials, and compatibility should be verified before use.
   　　最后，导致螺纹连接故障的主要原因来自于热塑性塑料内螺纹的过度紧固。建议采用美国斯毕尔公司的特别加固（SR）螺纹。
   　　Finally, the leading cause of thread joint failures is from over tightening female thermplastic threads. Use of Spears® Special Reinforced (SR) Threads is recommended.
9. 热塑性塑料管道系统内的液压冲击（水锤，冲击压力）可能会使管道、管件和阀门爆裂。应该计算预期冲击压力并使其不超过系统部件内部的最大压力等级（请参阅阀门的“非冲击”压力等级）。系统结构的安全性应该综合考虑释放压力和消除遗留空气。在热塑性塑料系统内，流体速度不应该超过每妙钟5英尺（1.5米）。
   Hydraulic Shock (water hammer; surge pressure) in thermoplastic piping systems can burst pipe, fittings, and valves. Anticipated surge pressures should be calculated and included in maximum internal pressure ratings of system components (specified "Non-Shock" pressure rating for valves). Safeguards should be incorporated in system design to vent pressures and eliminate entrapped air. Fluid velocities should not exceed a maximum of 5 feet per second in thermoplastic systems
10. 非液体传送 - 警告：美国斯毕尔制造公司建议不要将热塑性塑料管道产品用于传输或储存压缩空气或其他气体，或者用压缩空气或其他气体对于地面或地下热塑性塑料管道系统进行测试。将美国斯毕尔公司的产品用于压缩空气或其他气体系统将自动终止美国斯毕尔公司对这些产品的质量保证，对于与我们的建议相违背的应用所产生的后果完全由安装商负责。由于误用、不正确组装，和/或暴露在有害物质或环境下导致的结果或事故损失，美国斯毕尔制造公司不承担其损失或损害责任。
    Non-liquid transport - WARNING: Spears® Manufacturing Company DOES NOT RECOMMEND the use of thermoplastic piping products for systems to transport or store compressed air or gases, or the testing of thermoplastic piping systems with compressed air or gases in above or below ground locations. The use of Spears® products in compressed air or gas systems automatically voids Spears® warranty for such products, and their use against our recommendation is entirely the responsibility and liability of the installer. Spears® Manufacturing Company will not accept responsibility for damage or impairment from its products, or other consequential or incidental damages caused by misapplication, incorrect assembly, and/or exposure to harmful substances or conditions.