Are there diaphragm valves that can withstand 100-degree hydrochloric acid?
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Question: Is this the type of diaphragm valve suitable for use with a medium that is 20% hydrochloric acid, along with a small amount of solid particles – an oxide mineral of some metal?； Temperature: around 100°C ； It’s not known whether F4 or VITON has been used for the diaphragm material. Also, what is the approximate pressure drop when the diaphragm valve is fully open (DN100)? Thank you first!
Such valves certainly exist, but they are not necessarily of type F4 or made of VITON. Additionally, the pressure drop depends on your specific operating conditions; I’m unable to give you an answer at this time!
The corrosion issue is easy to resolve; the temperature is indeed a bit high, but it’s still no problem to use diaphragm valves with ETFE, PTFE, or PFA linings
I think using a diaphragm valve made of PVDF would be better. However, there is a problem: when the temperature of the medium is 100 degrees, the valve body made of PVDF can only withstand a pressure of 3 kilograms; when the temperature reaches 120 degrees, the allowable pressure drops to 2 kilograms. If the pressure conditions are even higher, it is recommended to use a metal diaphragm valve with a fully PTFE-lined valve body. I just completed an acid washing project recently, in which PVDF diaphragm valves were used, and I have considerable experience in this area! QQ: 928976489
Any fluoroplastic made of polytetrafluoroethylene will work, but if there are solid substances present, it is best not to use diaphragm valves. Plus 100 degrees of high temperature, the diaphragm valve wears out quickly. It is recommended to use other types of valves.
A diaphragm valve with a PVDF valve body and a PTFE diaphragm can meet the requirements. Diaphragm valves do not come in VITON material. The F4 and VITON you mentioned are both fluororubbers, with the latter encompassing the former. F4 is a fluororubber resistant to concentrated sulfuric acid. Regarding the issue of damping loss, generally speaking, for a DN100 diaphragm valve, if the selection is made based on flow rate and it meets the requirements, the damping loss is very small, to such an extent that it can be ignored for valves of this size.