Seal compatability for sodium hydroxide, Hypochlorous acid

[ThatShouldHaveWorked]

Based on what I've found for two separate pumps and chemicals.

EPDM is the preferred seal material for a stainless pump moving sodium hydroxide with PH between 10-12

Viton is the preferred seal material for a stainless pump moving hypochlorous acid with PH between 6-7

Can anyone confirm this for me?

Thanks

 

[pierreick]

Hi,
Sounds correct! You may want to test the gaskets in the solution(s) if you are worried.
The Ph of your caustic solution seems strange to me.
Check the spelling of your acid solution, one H is missing.
Good luck
Pierre

 

[ThatShouldHaveWorked]

Thanks for the confirmation and spell check. For whatever reason my brain hates that H.

 

[EdStainless]

This is for stronger acid than yours, but might provide some good info.

This gives some values for lower concentrations as well in Caustic.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[Artisi]

I've always contacted and taken advice from the seal suppliers, who else better to start with for a considered selection?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[ThatShouldHaveWorked]

I've always contacted and taken advice from the seal suppliers, who else better to start with for a considered selection?

I am a big believer in trust but verify. Now I have two sources that agree while I wait on the pump supplier to get back to me, and now I am ready when they do.

I can also cross it off my list and move on to the next thing.