The triple eccentric metal hard seal butterfly valve, as a high-performance valve, has advantages such as corrosion resistance, reliable sealing, and small opening torque. Its sealing surface is an inclined conical surface, and the contact between the valve body sealing ring and the butterfly plate assembly sealing ring is surface contact. Its working principle is to directly drive the butterfly plate assembly by the torque of the driving device, causing the sealing ring of the butterfly plate assembly to fully contact the valve body sealing ring and generate elastic deformation to seal. Structural Characteristics 1. The hard sealed butterfly valve adopts a three eccentric hard sealing structure, with almost no wear on the valve seat and butterfly plate, and has a sealing function that becomes tighter as the valve is closed. 2. The sealing ring is made of stainless steel, which has the dual advantages of metal hard sealing and elastic sealing. Both at low and high temperatures, it has excellent sealing performance, corrosion resistance, and long service life. 3. The sealing surface of the butterfly plate adopts surfacing cobalt based hard alloy, which is wear-resistant and has a long service life. 4. The large-sized butterfly plate adopts a quilted frame structure, with high strength, large flow area, and small flow resistance. 5. According to user requirements, hard sealed butterfly valves can be designed with bidirectional sealing function. During installation, it is not limited by the flow direction of the medium or affected by spatial location, and can be installed in any direction. 6. The drive device can be installed in multiple workstations (rotating 90 ° or 180 °), making it easy for users to use. Processing Technology Based on the structural characteristics of the triple eccentric metal hard seal butterfly valve, the sealing ring of the butterfly plate assembly is a combination of stainless steel plate, asbestos plate, or graphite. The valve body sealing ring is made of hard alloy with high hardness, and it is difficult to control the cutting amount, making it difficult to process and shape in one go. Moreover, the roughness requirements for the machined surface are very high. To ensure processing requirements, the process is as follows: Rough machining of valve body or butterfly plate assembly →→ Valve body sealing ring is welded with hard alloy for insulation and heat treatment to eliminate thermal stress →→ Sealing surface of rough turning of upper tooling →→ Upper tooling precision turning sealing surface →→ Grinding sealing surface with upper grinding head →→ Boring shaft holes for valve body and butterfly plate assembly →→ Strength test sealing test

Why is the globe valve designed with low inlet and high outlet? The globe valve is designed for low inlet and high outlet, with the aim of reducing flow resistance and saving effort when opening the valve. When the valve is closed at the same time, the gasket between the valve shell and valve cover and the packing around the valve stem are not subjected to force, which can prolong the service life and reduce the probability of leakage by not being subjected to medium pressure and temperature for a long time. In addition, this can also replace or add packing when the valve is closed, making maintenance easier. Many people believe that globe valves are low in and high out, but in fact, there are also some special situations where globe valves are high in and low out: 1. High pressure globe valve with a diameter greater than 100mm Due to the poor sealing performance of large diameter valves, when using this method to stop the valve in the closed state, the medium pressure acts on the valve disc to increase the sealing performance of the valve. 2. Two globe valves connected in series on the bypass pipeline, with the second globe valve requiring "high inlet and low outlet" To ensure the tightness of the valve within a maintenance cycle, valves that frequently open and close require the installation of two series globe valves. For the bypass system, the installation functions of this bypass include: ① Balance the pressure before and after the main pipeline valve, making it easy to open and labor-saving, and reducing the wear of the main pipeline valve; ② Warm up pipes with small and medium flow during startup; ③ On the main water supply pipeline, control the water flow to control the boiler pressure increase speed for boiler water pressure test. The bypass globe valves are divided into primary and secondary valves according to the direction of medium flow. During normal operation of the unit, the primary and secondary valves are closed and both come into direct contact with the medium. To prevent the gasket between the secondary valve shell and valve cover, as well as the packing around the valve stem from being subjected to medium and temperature effects for a long time, and to replace the valve packing during operation, the installation direction required for the secondary valve is "high in and low out". 3. Boiler exhaust and vent globe valves The boiler exhaust and vent globe valves are only used during the water supply process during boiler startup, with a small opening and closing frequency. However, they often cause fluid loss due to poor sealing. Therefore, some power plants have installed these globe valves in a "high inlet and low outlet" direction to improve their tightness. It is generally difficult to close the valve when using low inlet and high outlet methods under large caliber and high-pressure conditions. If low inlet and high outlet are used under high pressure and large diameter conditions, the valve stem is prone to deformation and ...

As a device for quickly removing gas from pipelines, exhaust valves are essential equipment for improving the efficiency of water conveying equipment and protecting pipelines from deformation and rupture. The exhaust valve is installed at the pump outlet or in the water supply and distribution pipeline to largely eliminate the accumulated air in the pipeline and improve the efficiency of water pipes and pumps. And once negative pressure occurs in the pipeline, this valve can quickly suck in air to prevent damage to the pipeline caused by negative pressure. The exhaust valve is generally used for pipe exhaust of independent heating system, central heating system, heating boiler, central air conditioning, floor heating and solar heating system. Precautions for setting exhaust valves: 1. The exhaust valve must be installed vertically, that is, it must ensure that the internal float is in a vertical state to avoid affecting the exhaust. 2. When installing the exhaust valve, it is best to install it together with the isolation valve, so that when the exhaust valve needs to be removed for maintenance, it can ensure that the system is sealed and water does not flow out. 3. The exhaust valve is generally installed at the highest point of the system, which is beneficial for improving exhaust efficiency. Performance requirements for exhaust valves: 1. The exhaust valve should have a large exhaust capacity, which can quickly exhaust and restore to normal water supply capacity in a very short time when the pipeline is empty and filled with water. 2. When there is negative pressure generated in the exhaust valve inside the pipe, the piston should be able to quickly open and absorb a large amount of external air to ensure that the pipeline will not be damaged due to negative pressure. And it can expel trace amounts of air accumulated in the pipeline under working pressure. 3. The exhaust valve should have a relatively high air closing pressure, and should have sufficient capacity to exhaust the air in the pipeline in a short period of time before the piston is closed, thereby improving the water delivery efficiency. 4. The water closing pressure of the exhaust valve should not exceed 0.02 MPa, and the exhaust valve can be closed at a lower water pressure to avoid a large amount of water gushing out. 5. The exhaust valve should use stainless steel floating balls (floating barrels) as the opening and closing parts. 6. The exhaust valve body should be equipped with an anti impact protection inner cylinder to prevent premature damage to the floating ball (bucket) caused by the direct impact of high-speed water flow after a large amount of exhaust. 7. For exhaust valves with DN ≥ 100, a split structure is adopted, consisting of a large number of exhaust valves and automatic exhaust valves to meet the requirements of pipeline pressure. 8. For high flow rates, frequent start of water pumps, and operating conditions with a diameter DN ≥ 100, a buffer plug valve should...