The medium is hydrogen; why are hard-sealed valves used for the ball valves selected?

On the sealing material: Soft and hard sealing refer to the sealing material of the valve seat. Hard sealing involves precisely machining the valve seat material to ensure a precise fit with the valve core (sphere); materials used for this purpose are typically stainless steel and copper. A soft seal refers to a sealing material that is made of a non-metallic material and is embedded in the valve seat; due to the elasticity of this soft sealing material, the requirements for machining precision are relatively lower compared to hard seals. In terms of operating conditions: soft seals generally achieve very high levels of sealing performance, while hard seals can have varying degrees of sealing effectiveness depending on the requirements ； Soft seals need to be fire-resistant, as the material of soft seals can leak at high temperatures, whereas hard seals do not have this problem ； Hard seals can generally handle very high pressures, while soft seals cannot ； Due to the properties of the medium flowing through it, soft seals cannot be used in certain situations (such as with corrosive media) ； Finally, hard-sealed valves are generally more expensive than soft-sealed ones. As for manufacturing, there is not much difference between the two; the main difference lies in the valve seat – the soft seal uses non-metallic materials, while the hard seal uses metallic materials.