At present, the application of Lianggong valve in Shanghai is still relatively common in the market. All kinds of valve brands have their own market, which is also related to the hot market environment. However, the valves commonly used in water supply pipeline system include gate valve (thread and flange), stop valve (thread and flange), check valve (thread and flange), butterfly valve, etc.

(1)閘閥：可采用明桿、暗桿、手動、電動、電機驅動。本實用新型具有流體阻力小，啟閉力小，介質可從任何方向流動的優點。但結構復雜，閘板密封面易被水中雜質或顆粒摩擦或沉積在閥體底部，造成關閉不嚴的缺陷。頻繁開啟的閘閥有時會從閥板上脫落，導致系統失去控制能力。

(1) Gate valve: it can be driven by exposed rod, concealed rod, manual, electric and motor. The utility model has the advantages of small fluid resistance, small opening and closing force, and the medium can flow from any direction. However, the structure is complex, and the sealing surface of the ram is easy to be rubbed or deposited at the bottom of the valve body by impurities or particles in the water, resulting in the defect of loose closing. Frequently opened gate valves sometimes fall off the valve plate, resulting in loss of control of the system.

(2)截止閥：與閘閥相比，具有結構簡單、密封性能好、維修方便等優點，但啟閉力略大于閘閥。安裝時注意閥體上的箭頭(水流)方向，不要反向安裝。

(2) Stop valve: compared with gate valve, it has the advantages of simple structure, good sealing performance and convenient maintenance, but the opening and closing force is slightly greater than that of gate valve. Pay attention to the direction of the arrow (water flow) on the valve body during installation, and do not install in the opposite direction.

(3)蝶閥：在給水管道上起全開和全關作用的閥門。其啟閉力大，但閥體小而輕。

(3) Butterfly valve: a valve that plays the role of full opening and full closing on the water supply pipeline. Its opening and closing force is large, but the valve body is small and light.

蝶閥有很多種，包括手柄式、蝸輪傳動式、電動式、氣動式等。

There are many kinds of butterfly valves, including handle type, worm gear drive type, electric type, pneumatic type, etc.

(4)止回閥：又稱止回閥，它是一種只允許介質單向流動的閥門，因此具有嚴格的方向性。主要用于管道上防止水倒流。

(4) Check valve: also known as check valve, it is a valve that only allows one-way flow of medium, so it has strict directionality. It is mainly used to prevent water backflow on the pipeline.

常用的止回閥有提升式和旋啟式。提升式垂直盤式止回閥應安裝在垂直管道上;提升式水平盤式止回閥和旋啟式止回閥應安裝在水平管道上。安裝時注意閥體箭頭方向，不得反向安裝。那么上述就是我們上海良工閥門代理為大家帶來的全部內容分享了，希望大家可以作為參考!

Common check valves are lift and swing. Lift type vertical disc check valve shall be installed on vertical pipeline; Lift type horizontal disc check valve and swing type check valve shall be installed on horizontal pipeline. Pay attention to the arrow direction of the valve body during installation, and do not install in the opposite direction. So the above is all the content that our Shanghai Lianggong valve agent has brought to you. I hope you can use it as a reference!