閥門選定和管道設計時，應注意事項如下：

　　Selection of valves and design of pipes shall comply with the following principals:

　　1、根據閥門使用場所、用途且了解有關法規、規格、標準、方針、許用認可后即可選用適合各種要求的閥門；

　　In terms of locations and purposes of valves, the suitable valves can be selected after knowing relevant specification, size,

　　standards,principal and permission;

　　2、確定閥門的工作條件、適用介質、工作壓力、介質溫度

　　Need to specify the working condition, applicable medium, working pressure and working temperature of media;

　　3、確定與管道相匹配的公稱通徑DN  （mm）

　　Need to specify the nominal diameter to match the pipeline: DN（mm）

　　4、確定與管道相連接方式法蘭式、內（外）螺紋式、焊接式、對夾式、卡箍式、卡槽式、卡套式等

　　Need to specify the connecting type of the pipeline, including flanged type, inside&outside screwed type, welded type, wafer

　　type, clip type, groove

　　type,and union type etc.;

　　5、確定閥門的操作方式：手動、蝸輪動、氣動、電動、液動、電磁動、電液動

　　Need to specify the operating type of the valve, including lever, worm gear, pneumatic actuator, hydraulic actuator,

　　electromagnetic actuator and electromagnetic-hydraulic actuator etc.;

　　6、確定閥門的類型閘閥、截止閥、節流閥、球閥、蝶閥、隔膜閥、旋塞閥、止回閥、安全閥、減壓閥、疏水閥、柱塞閥、水力控制閥及其他特種閥

　　Need to specify the model of the valve, including gate valve, globe valve, throttle valve, ball valve, butterfly valve, diaphragm

　　valve, plug valve, check valve, safety valve, reducing valve, steam trap and plunger valve etc.;

　　7、確定閥門的使用形式開關型、調節型、安全型等

　　Need to specify the working type of valve, including on-off type, adjusting type, safety type etc.;

　　8、確定閥門殼體及內件的材料灰鐵、球鐵、碳鋼、合金鋼、不銹鋼、蒙乃爾合金、銅合金、鋁合金、塑料等

　　Need to specify material of body and trim, including grey iron, ductile iron, carbon steel, alloy steel, stainless steel, monel alloy,copper alloy, aluminum alloy, plastic etc.;

　　9、確定閥門的密封性能要求、密封等級或密封泄露量

　　Need to specify the requirements on

　　10、確定閥門的防護涂層要求、包裝要求、運輸要求

　　seal performance and grade or leakage;

　　Need to specify the requirements on coating, packing and transportation;

　　11、特殊需要的閥門還應確定結構長度、閥門高度、外形尺寸、流阻、排放能力、流量特性、防護等級、防爆性能等參數

　　Need to specify face to face dimension, height, outline sizes, flow resistance, drainage ability, flow characteristic, protected

　　grade, anti-explosive performances etc. for special valves;

　　12、確定閥門的安裝位置及姿勢

　　Need to specify the installed position and direction for the valve.