一、进口焊接高压止回阀

进口高压焊接止回阀是指采用对焊或者承插焊的连接方式，锻造高压的止回阀，能自动阻止流体倒流的阀门。止回阀的阀瓣在流体压力作用下开启，流体从进口侧流向出口侧。当进口侧压力低于出口侧时，阀瓣在流体压差、本身重力等因素作用下自动关闭以防止流体倒流。

美国威盾VTON进口焊接高压止回阀适用于公称压力PN20.0～32.0Mpa，工作温度≤540℃(其中P(57)170V工作温度为570℃)的石油、化工、水力、火力电站等各种工况的管路上，切断或接通介质。

High pressure welding check valve refers to a forged high pressure check valve that uses butt welding or socket welding connection methods and can automatically prevent fluid backflow. The valve disc of the check valve opens under fluid pressure, and the fluid flows from the inlet side to the outlet side. When the pressure on the inlet side is lower than that on the outlet side, the valve disc automatically closes under the influence of factors such as fluid pressure difference and gravity to prevent fluid backflow.

VTON welded high-pressure check valves are suitable for cutting off or connecting media on pipelines under various working conditions, such as petroleum, chemical, hydraulic, and thermal power plants, with a nominal pressure of PN20.0-32.0Mpa and a working temperature of ≤ 540 ℃ (where P (57) 170V has a working temperature of 570 ℃).

二、进口焊接高压止回阀规范标准

口径：DN15－600(2″－24″)

公称压力：150LB－4500LB，按ASME标准

适用温度：－46℃～650℃

阀体材料：碳钢 合金钢和不锈钢，按ASME和DIN标准

连接方式：对焊，承插焊，BW，SW

适用介质：高温高压水，蒸汽，油品，以及各种气体

三、进口焊接高压止回阀结构特点

焊接止回阀一般分为升降式、旋启式等几种类型。 

升降式止回阀的结构一般与截止阀相似，其阀瓣沿着通道中心线作升降运动，动作可靠，但流体阻力较大，适用于较小口径的场合。升降式止回阀可分为直通式和立式两种。直通式升降式止回阀一般只能安装在水平管路，而立式升降止回阀一般应安装在垂直管路。 

旋启式止回阀的阀瓣绕转轴作旋转运动。其流体阻力一般小于升降式止回阀，它适用于较大口径的场合。旋启式止回阀根据阀瓣的数目可分为单瓣旋启式、双瓣旋启式及多瓣旋启式三种。单瓣旋启式止回阀一般适用于中等口径的场合。大口径管路选用单瓣旋启式止回阀时，为减少水锤压力，最好采用能减小水锤压力的缓闭止回阀。双瓣旋启式止回阀适用于大中口径管路。对夹双瓣旋启式止回阀结构小、重量轻，是一种发展较快的止回阀；多瓣旋启式止回阀适用于大口径管道路。

Welding check valves are generally divided into several types, such as lift type and swing type.

The structure of a lift check valve is generally similar to that of a globe valve. The valve disc moves up and down along the centerline of the channel, with reliable action, but with high fluid resistance, making it suitable for smaller diameter applications. Lift check valves can be divided into two types: straight through and vertical. Direct lift check valves can generally only be installed in horizontal pipelines, while vertical lift check valves should generally be installed in vertical pipelines.

The disc of a swing check valve rotates around the shaft. Its fluid resistance is generally smaller than that of lift check valves, making it suitable for larger diameter applications. Swing check valves can be divided into three types based on the number of valve discs: single disc swing, double disc swing, and multi disc swing. Single disc swing check valves are generally suitable for medium caliber applications. When using a single disc swing check valve for large-diameter pipelines, it is best to use a slow closing check valve that can reduce water hammer pressure. Double disc swing check valves are suitable for large and medium diameter pipelines. The double disc swing check valve has a small structure and light weight, making it a rapidly developing check valve; The multi disc rotary check valve is suitable for large-diameter pipe roads.

四、进口焊接高压止回阀主要零部件材质