Selection of 50% hydrogen peroxide shut-off valve
Thread Content
I would like to ask everyone: when it comes to cut-off valves for 50% hydrogen peroxide, is it necessary to use butterfly valves instead of ball valves? Also, how to choose between soft seal and hard seal? Design pressure: 1 MPaG ； Design temperature: 100℃ ；
Ball valves cannot be used, and butterfly valves are not necessarily the only option. You can also choose globe valves, gate valves, etc. The choice between soft seal and hard seal should be determined based on the actual operating conditions and the properties of the medium. 50% hydrogen peroxide is highly corrosive; soft seals are generally recommended. However, the temperature and pressure of the medium must be taken into account to ensure that the sealing material can withstand hydrogen peroxide and provides good sealing performance at the design temperatures and pressures. .
For hydrogen peroxide, it isn’t necessary to use butterfly valves; ball valves are avoided because they could lead to decomposition and explosion of the hydrogen peroxide in the sealed space created by the valve core once it is closed. There are also ball valves that have been specifically designed for handling hydrogen peroxide and for allowing fluid discharge. However, with a design temperature of 100 degrees, hydrogen peroxide decomposes very easily. . The seal can be either soft or hard. Seals made of PTFE don’t soften either; that’s all I know. If there are any mistakes, please point them out, experts
It’s not necessarily necessary to use butterfly valves. As mentioned on the second floor, during safety inspections, those safety experts might raise the concern mentioned there: when the valve is closed, hydrogen peroxide can remain inside the ball valve, leading to decomposition and explosion. I’m not sure if there are any regulations regarding this, but at least 30% of the hydrogen peroxide used in our company is handled at room temperature using ball valves for shut-off, and no problems have arisen. As for the 100 degrees mentioned by the original poster, it’s unclear whether safety issues will arise
For the previous project, a hydrogen peroxide on/off valve was just designed; the following points can be used as references: 1. We chose a ball valve, and drilling is required on its valve core. (The drilling dimensions and direction are in accordance with the specifications for pipeline materials and process requirements.) The special structural design of the valve manufacturer ensures a tight seal, and when pressure builds up due to the decomposition of the medium inside the valve core, pressure is released back into the pipeline through small holes. 2. The valve’s liquid-contacting parts are subjected to deoxidation and degreasing treatment. 3. The valve’s liquid-contacting components do not contain graphite, as graphite reacts with hydrogen peroxide.
We use ball valves with pressure relief holes
If high requirements are placed on the sealing performance of the valve, a soft-sealed ball valve can be chosen； If high requirements are placed on the cost of the valve and its opening/closing speed, a hard-sealed butterfly valve can be chosen
For hydrogen peroxide storage tank shut-off valves, for pipes sized 4 inches or smaller, use a ball valve with holes (to prevent hydrogen peroxide from getting trapped in the ball when the valve is closed). For pipes larger than 4 inches, butterfly valves can be used. The ball valve uses a floating ball soft seal (PTFE)