discharge pipe

I'm in the process of remodeling a property built in 1954, and wanted to move the washing machine discharge pipe into the wall. I had a plumber out who wanted to move the p-trap from the end of the run to the stand pipe. This differs from the research I have done. It appears what needs to...

Hi All. I just have a unit installed. Do I really need to have a discharge pipe installed? The tank is filled with water and air has been purged. The TP relief valve is installed. If pressure gets too high I assume I would see leak from the valve. It’s at a small business and flooring is tile...