工程规格说明书范文
Sample Engineering Specification

　　所有热塑性塑料止回阀应该是真活接实用旋启式止回阀或真活接实用弹簧止回阀，结构材料应该是PVC类型I, ASTM D 1784分类12454。所有活接头螺母应该是锯齿螺纹，并连接到带EPDM阀座和加重阀瓣的可更换密封装置。所有弹簧止回阀应该配置不锈钢弹簧辅助操作。所有阀门应该获得美国国家卫生基金会NSF国际部认证可用于饮用水。在水温23^oC条件下，所有阀门在全流量（开启）位置时压力等级为150 psi，在回压（关闭）位置时压力等级为75 psi，并由美国斯毕尔制造公司制造。
　　All thermoplastic check valves Shall be True Union Utility Swing Check or True Union Utility Spring Check type constructed form PVC Type I, ASTM D 1784 Cell Classification 12454. All union nuts shall have Buttress threads coupled to a replaceable sealed unit with EPDM seat and weighted disc. All Spring Check Valves shall have stainless steel spring assisted operation. All valves shall be certified by NSF International for use in potable water service. All valves shall be pressure rated to 150 psi for water @ 73^oF in full flow (open) position and to 75 psi @ 73^oF back pressure (closed), as manufactured by Spears® Manufacturing Company.

真活接实用旋启式止回阀快速选型表
Quick-View True Union Utility
Swing Check Valve Selection Chart

特点 - PVC白和PVC透明
Features - PVC White & PVC Clear

　　美国斯毕尔公司真活接实用旋启式止回阀和弹簧辅助真活接实用弹簧止回阀是一种结构紧凑、高性能止回阀，适用于景观、灌溉、泳池、温泉、水产业、OEM和许多通用应用场合。真活接结构便于无需维护密封装置的在线更换。这些阀门配置耐用EPDM弹性材料阀座及加重阀瓣，适用于全流量，减少流体流动阻力，实现积极有效关闭。弹簧辅助的“弹簧止回阀”型号采用正压力弹簧，有助于避免阀门关闭时出现拍击现象。结构材料采用PVC白或CPVC透明，连接端口采用承插、螺纹或SR螺纹，国际管道标准IPS通径范围从DN15 ~ DN100。
　　Spears® True Union Utility Swing Check and spring assisted True Union Utility Spring Check Valves offer a compact, high performance check valve for Landscape & Irrigation, Pool & Spa, Aquaculture, OEM and many general purpose applications. True Union design allows for easy in-line replacement of maintenance free sealed units. These valves feature long-life EPDM elastomer seats with weighted disc for full-flow with minimal restriction and positive shutoff. Spring assisted "Spring Check" model incorporates a positive-pressure spring to assist in valve closing without slamming. Produced from PVC White or PVC Clear material with Socket, Threaded or SR Threaded end connectors in IPS Sizes ¹/₂" through 4".

• 耐化学品和耐腐蚀的PVC白和高透明度的PVC透明结构材料
  Chemical & Corrosion Resistant PVC White or High Visibility PVC Clear Construction
• 旋启式止回阀没有金属部件 - 弹簧止回阀配置不锈钢弹簧
  No Metal Parts on Swing Check - Stainless Steel Spring on Spring Check
• 易于蜜蜂装置在线更换的真活接头
  True Union style for Easy In-line Replacement of Sealed Unit
• 坚固的锯齿螺纹活接头螺母
  Strong Buttress Threaded Union Nuts
• 工程设计用于实现最大流量、快速反应和积极有效的关闭
  Engineered for Maximum Flow, Quick Response & Positive Shutoff
• 耐用、高等级EPDM阀座，带加重阀瓣
  Long-Life, High Grade EPDM Seat with Weighted Disc
• 弹簧辅助的弹簧止回阀型号选项，用于积极有效的关闭
  Spring Assisted Spring Check Model Option for Positive Closing
• 压力等级为150 psi @ 23^oC全流量（开启），和75 psi @ 23^oC回压（关闭）
  Pressure Rated to 150 psi @ 73^oF Full-Flow (open) and 75 psi @ 73^oF Back Pressure (closed)
• 适用于水平或垂直朝上安装，以及真空应用场合
  Suitable for either Horizontal or Vertical Up-flow Installations and Vacuum Service
• 获得美国国家卫生基金会NSF认证可用于饮用水
  NSF Certified for Potable Water Use
• 无硅树脂组装
  Silicone-Free Assembly

真活接实用弹簧止回阀快速选型表
Quick-View True Union Utility
Spring Check Valve Selection Chart