Qingdao Fluido Industrial Co. Ltd.

DN refers to the nominal diameter, a dimensionless number indicating the size of the flange, while PN indicates the pressure rating, representing the maximum allowable pressure at a specific temperature.

Common Butt weld fittings types include elbows, tees, reducers, and caps, with materials like carbon steel, alloy steel, and stainless steel often used. 

A foot valve is a type of check valve typically installed at the bottom of a suction line, often in pumps, to prevent backflow of liquid and maintain the pump's prime

A pipe coupling, also known as a coupler, is a short pipe fitting used to connect two pipes together, either to extend a pipeline, change its size, or repair a leak. 

A non-return valve lets the fluid flow in one direction. When fluid in the line reverses direction and begins to flow back the way it came, a check valve serves to stop or prevent the backflow by allowing flow in one direction.

Globe valves are designed for throttling and regulating flow, while gate valves are primarily used for on/off control and isolation

Valves are essential components in fluid systems, offering control over flow direction, pressure, and volume. They can be broadly categorized into manual, actuated, and automatic types, each with various subtypes. Selection depends on factors like fluid type, pressure, temperature, flow requirements, and desired actuation method.

A check valve, also known as a one-way or non-return valve, allows fluid (liquid or gas) to flow in only one direction. It prevents backflow, ensuring that the fluid moves in the desired direction and protects the system from damage.