Hard sealed gate valve: A valve with both sides of the sealing pair made of metal or other harder materials is called a "hard seal". This type of seal has poor sealing performance, but it is wear-resistant and has good mechanical properties.

Hard sealed gate valves have a simple structure, small size, and light weight, consisting of only a few components. And it only needs to be rotated 90 ° to open and close, with simple operation, and the valve has good fluid control characteristics. When the flange butterfly valve is in the open position, the thickness of the butterfly plate is the resistance of the medium flowing through the valve body, so the pressure drop generated by this valve is very small, thus it has good flow control characteristics. Butterfly valves have two sealing types: elastic sealing and metal sealing. Elastic sealing valve, the sealing ring can be embedded on the valve body or attached around the butterfly plate. Valves with metal seals generally have a longer lifespan than those with elastic seals, but it is difficult to achieve sealing.

Metal hard sealed gate valves can adapt to higher operating temperatures, while elastic seals have the drawback of being limited by temperature. If butterfly valves are required for flow control, the main thing is to choose the correct size and type of valve. The structural principle of butterfly valves is particularly suitable for making large-diameter valves.

Hard sealed gate valves are widely used not only in general industries such as petroleum, gas, chemical, and water treatment, but also in cooling water systems of thermal power plants. There are two commonly used butterfly valves: clamp type butterfly valve and flange type butterfly valve. The clamp type butterfly valve is connected between two pipeline flanges with double headed bolts. The flange type butterfly valve has a flange on the valve, and the flanges on both ends of the valve are connected to the pipeline flange with bolts.

When the hard sealed gate valve is in the open position, the thickness of the butterfly plate is the resistance of the medium flowing through the valve body, so the pressure drop generated by this valve is very small, thus it has good flow control characteristics.