Pneumatic Fittings in Corrosive Environments 1

[Brent Boisvenue]

I work in industrial automation and we design and build machines for electrolytic tankhouse applications that tend to contain significant sulfuric acid mist in the air. We typically use a lot of pneumatics for pneumatic actuators on different parts of our machines and robot end of arm tooling. We are starting to get feedback; however, that the SMC KQ2 series fittings (plastic fittings) that we typically use are disintegrating from corrosion due to the acid mist in the air (an outside factor - the air inside our pneumatics is clean dry air). Specifically, the release buttons disintegrate and the fitting leaks, which I just found out are made of POM and have no resistance to sulfuric acid. I've uploaded a photo of a fitting with a corroded release button.

I have the option of selecting the SMC KQG2 series fittings that are all stainless steel, but they come at a premium. I have several queries out with other vendors, but I'm wondering if anyone has had good luck with a different brand of economical good quality plastic fittings that hold up well to sulfuric acid attack.

 

[btrueblood]

You should be able to find quick-connect polypropylene fittings that would work, and are cheap. But if you want to know you are ok, look for PPS or PVDF fittings - McMaster carries them. I could only find acetal, brass and stainless on the SMC website.

 

[Brent Boisvenue]

Tanks @btrueblood. I did find fittings through FESTO that are polypropylene. I will probably go with that.