A condo complex I am associated with uses 4 Stenner pumps located inside a building - 2 for acid and 2 for chlorine for a pool and spa with a couple of Chemtrol pc2100 controllers. They went in last year and the tubes should be changed soon, (and downsized from a 5 to a 1 or 2). I've viewed the Stenner video on changing pump tubes and it looks pretty straight forward, but I am wondering about the acid pump safety issues. We've noticed that the lines to the tanks, which are outside don't fill completely with fluid, making us think we have some small air leaks, so we are going to change all the ferrules as Stenner says the tubes should be full after a startup period.
It is recommended to run a buffer solution or water before servicing the pumps, and as they are inside and near other equipment we don't want to have *any* spills. I thought we'd pull the feed tubes and drop them in water, and run the pump continuously until the water was clearly depleted to flush the pumps and then pull everything apart with gloves and eye protection.
My question is related to the restart when we re-insert the tubing into the (non dilute) acid drums. The tubes will be full of water, and I'm mindful of the "don't add water to acid" mantra. I think the tube will end up being be the site of an exothermic reaction. Should we run the pumps until the lines are dry before reinserting?
Any other tips for chemical safety during a tube change?