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可调节弹簧止回阀类型，其结构材料应该采用PVC类型I, ASTM D 1784分类12454。所有阀门阀座材质应该是EPDM。所有阀门应该有外置箭头流向标志。在水温23^oC条件下，所有阀门压力等级应该是200 psi，并由美国斯毕尔制造公司制造。
　　All thermoplastic check valves shall be Adjustable Spring Check type constructed from PVC Type I, ASTM D 1784 Cell Classification 12454. All Valve Seats shall be EPDM. All valves shall have external Arrow Flow Indicator. All valves shall be pressure rated to 200 psi water at 73^oF, as manufactured by Spears® Manufacturing Company.

快速阀门选型表
Quick-View Valve Selection Chart

特点 - PVC
Features - PVC

　　可调节的特性使得阀门能够在系统内进行回压控制，减少水锤现象，并且防止虹吸现象的发生。很容易就能把压头调回5至32英尺，调节螺丝每旋转一整圈，就能调低1 psi（相当于压头2.3英尺）。特别适用于景观和灌溉场合，节省空间的在线结构便于快速安装。
　　Adjustable feature allows control of back pressure in system, reduces water hammer, and prevents siphoning. Easily adjusts to hold back from 5 to 32 feet of pressure head, 1 psi (2.3 feet of head) for each full turn of the adjustment screw. Ideal for landscape and irrigation applicators, quickly installs with space saving in-line design.

• 2 ~ 14磅可调节弹簧拉力（5至32压头英尺）
  工厂预置为大约5 psi（12压头英尺）
  2 - 14 lbs. Adjustable Spring Tension (5 to 32 feet of head) Factory Preset to Approx. 5 psi (12 feet of head)
• 不锈钢调节弹簧，配置EPDM材质阀座
  Stainless Steel Adjustment Spring with EPDM Seat
• 在水温23^oC条件下，压力等级为200 psi
  Pressure Rated to 200 psi for water @ 73^oF
• 可提供的标准装置为DN15, DN20, DN25和DN15 x DN20通径Fipt进口 x Mipt出口结构
  Standard Unit Available in ¹/₂", ³/₄", 1" & ¹/₂" x ³/₄" with Fipt Inlet x Mipt Outlet Configuration
• 此外，还可提供很受欢迎的备选DN15通径Mipt进口 x Fipt出口和DN20通径Fipt进口 x Fipt出口结构
  Plus, Popular Configuration Options of ¹/₂" Mipt Inlet x Fipt Outlet & ³/₄" Fipt Inlet x Fipt Outlet

备件
Replacement Parts