Q: We’re making some changes in our waste water treatment process and are going to using hydrochloric acid (HCl) as a means of lowering the pH levels. Will I need to upgrade my duplex bolting?
A: Assuming your waster water is at ambient temperatures the only thing you need to worry about is the concentration of the HCl. By your inlet, it may be highly concentrated requiring different bolting further upstream than down stream. Depending on the your PH, you certainly will be safe with Hastelloy C276 bolts by the injection ports. Further downstream you will probably be OK with duplex bolts as the acid injected dilutes out.