For high-pressure raw material gas under bidirectional pressure, what type of butterfly valve should be used?

Are the leakage level requirements high? It is usually a triple-eccentric butterfly valve or a double-eccentric butterfly valve, but I’m not quite sure what is meant by dual pressure resistance

What is the diameter, and are high leakage limits required? Butterfly valves are generally used for flow regulation; if strict requirements exist, can ball valves or gate valves be used as alternatives?

A two-way flow, hard-sealing rotary ball valve could be considered

Detailed Explanation: The two-way flow hard-sealing rotary ball valve was developed by combining the excellent sealing properties of ball valves with the advantageous structural features of butterfly valves. It boasts the practical benefits of ball valves, such as two-way sealing, adjustability, and long service life, as well as the structural advantages of butterfly valves, including a small size and light weight. Its essence is an eccentric hemispherical valve with a butterfly structure! The sealing principle combines the front-end sealing of a fixed ball valve with the forced sealing of an eccentric butterfly valve, thereby enabling two-way isolation at both high and low pressures. On the two sealing surfaces of the sealing pair, advanced processes such as space plasma spraying, electron beam laser sputtering, and vacuum-assisted coating can be employed to create gradient functional materials such as martensitic stainless steel, austenitic stainless steel, cemented carbide, cermets, and synthetic diamond, depending on the required hardness levels. It can automatically center itself (adaptively), automatically compensate for wear through overshoot correction, apply an extremely high sealing pressure, close and open instantly with no friction between the sealing surfaces. When opened, the projection of the valve core expands and moves forward continuously. Its compact structure allows for the manufacture of valves with large, extra-large, and super-large diameters. It offers a range of advantages such as ease of transportation, installation, maintenance, and reliable operation, representing a major technological revolution in the valve industry. Advantages of the two-way flow hard-sealing rotary ball valve: 1. It can be reliably closed not only under forward pressure, but also under reverse pressure, or when the reverse pressure is much higher than the forward pressure ； 2. On the two sealing surfaces of the sealing pair, advanced processes such as space plasma spraying, electron beam laser sputtering, and vacuum-assisted infiltration cladding can be employed to create gradient functional materials such as martensitic stainless steel, austenitic stainless steel, cemented carbide, cermets, and synthetic diamond, depending on the required hardness levels ； 3. It can automatically align the center (adaptively), and it can also automatically compensate for wear through overshoot ； 4. When shutting down, the energy of the medium inside the valve is fully utilized to generate an extremely high sealing pressure, ensuring reliable zero leakage for the high-stiffness sealing pairs ； 5. Instant shutdown and instant startup – no friction between the sealing surfaces. When it opens, the projected cross-section of the valve core continuously contracts and retracts, with the retraction occurring more rapidly at the initial stage of opening than the contraction. During closure, the projected cross-section of the valve core continues to expand and move forward; at the beginning of closure, the expansion rate is greater than the moving speed, while at the end of closure, the moving speed is greater than the expansion rate. Features of an eccentric hemispherical valve (high-pressure ball valve), globe valve, and wedge gate valve ； 6. Its main structure is similar to that of a butterfly valve, boasting the advantages of short length and small size associated with butterfly valves; therefore, valves with large, extra-large, and super-large diameters can be manufactured ； The two-way flow hard-sealing rotary ball valve combines the functions and advantages of butterfly valves, hemispherical valves, gate valves, and globe valves, while also possessing its own unique and powerful functions and advantages. Its advantages such as small size, light weight, ease of transportation, installation, maintenance, and reliable operation have marked a major technological revolution in the valve industry.

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Double-sealing refers to the situation where both sealing surfaces have been subjected to pressure testing, with the smoother side serving as the inlet side. Seals are divided into soft seals and hard seals

Large diameter, 120 pressure – this butterfly valve is quite challenging. There is also bidirectional pressure; I don’t know what the reverse pressure is

Butterfly valves are generally not recommended for gas valves as they are prone to leakage. If it’s to be used, the best option at the moment is a triple-eccentric butterfly valve. But it’s hard to say when under pressure on both sides. Gate valves are recommended as they provide good leak prevention and have a strong capacity to withstand pressure from both sides.

Ball valves are also a great choice. Moreover, the technology is mature, so butterfly valves do not necessarily have an advantage in this regard.

Under normal operation, the pressure on both sides is around 120 kilograms, with little pressure difference between them; however, the pressure difference becomes large during shutdown or startup.