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实用旋启式止回阀或实用弹簧止回阀，结构材料应该采用PVC类型I, ASTM D 1784分类12454。所有阀门应该是无需维护密封装置结构，并配置EPDM阀座和加重阀瓣。所有弹簧止回阀应该配置不锈钢弹簧辅助运行。所有阀门应该有外置流向箭头。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）位置时压力等级应该是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 Utility Swing Check or Utility Spring Check type constructed form PVC Type I, ASTM D 1784 Cell Classification 12454. All valves shall be maintenance free seal unit construction with EPDM seat and weighted disc. All Spring Check Valves shall have stainless steel spring assisted operation. All valves shall have external flow arrow direction designation. 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.

快速实用旋启式止回阀选型表
Quick-View Utility Swing Check
Valve Selection Chart

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

　　美国斯毕尔公司实用旋启式止回阀和弹簧辅助实用弹簧止回阀为景观和灌溉，泳池和温泉，水产业，OEM和许多通用应用场合提供紧凑、高性能止回阀。这种无需维护密封装置配置耐用的EPDM弹性材料阀座，并带加重阀瓣，以最大限度减少流体流动阻力，实现积极有效的关闭。弹簧辅助“弹簧止回阀”型号整合正压力弹簧，以辅助阀门在不拍击状况下关闭阀门。结构材料采用PVC白或PVC透明，连接端口采用承插，螺纹或SR螺纹。可提供国际管道标准IPS通径DN15至DN200的旋启式止回阀，以及通径DN15至DN100的弹簧止回阀。
　　Spears® Utility Swing Check and spring assisted Utility Spring Check Valves offer a compact, high performance check valve for Landscape & Irrigation, Pool & Spa, Aquaculture, OEM and many general purpose applications. These maintenance free sealed units 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. Available in IPS Sizes ¹/₂" through 8" for Swing Check Valves and ¹/₂" through 4" for Spring Check valves.

• 耐化学品和耐腐蚀PVC白或高透明度的PVC透明材料结构
  Chemical & Corrosion Resistant PVC White or High Visibility PVC Clear Construction
• 在旋启式止回阀上没有金属部件 - 弹簧止回阀采用不锈钢弹簧
  No Metal Parts on Swing Check - Stainless Steel Spring on Spring Check
• 无需维护的密封装置，结构紧凑小型，节省空间
  Maintenance Free Sealed Unit in a Compact Space Saving Design
• 工程结构有利于实现流量最大，反应迅速，关闭积极有效
  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
• 可提供弹簧辅助的弹簧止回阀型号用于积极有效的关闭
  Spring Assisted Spring Check Model Option for Positive Closing
• 通径DN15 ~ DN200压力等级为150 psi @ 23^oC全流道（开启）和75 psi @ 23^oC回压（关闭）
  Sizes ¹/₂" - 8" Pressure Rated to 150 psi @ 73^oF Full-Flow (open) and 75 psi @ 73^oF Back Pressure (closed)
• 适用于水平管道安装或垂直朝上的管道安装，以及真空应用场合
  Suitable for either Horizontal or vertical Up-flow Installations and Vacuum Service
• 美国国家卫生基金会NSF认证可用于饮用水
  NSF Certified for Potable Water Use
• 无硅树脂组装而成
  Silicone-Free Assembly

快速实用弹簧止回阀选型表
Quick-View Utility Spring Check
Valve Selection Chart