Had a water heater installed by plumber. Told him I wanted the metal tap I had to be substituted for the cheapie tap on the bottom. Just prior to my departing to leave him to it, I noticed him taking an arc joint pliers to the plastic tap. A little while later, it was discovered the new tap did not fit the heater. Hmmm ... We're approaching overtime and, in a quick search, could not locate an acceptable tap. Told him to install the cheapie. With a finger in the cookie jar look, he showed me the mangled remains his arc joint pliers had left. With the clock ticking, I handed him a brass nipple and cap to use to have him stop his clock. Now, I want to install a tap so I can "flush" the heater when desired. The question is, with the incoming water tap and all house taps closed, at what force will the water exit the heater when I remove the cap from the brass nipple ... a rush, a slow stream, or somewhere between? If not much force, I may decide to leave the cap as is. If it's forceful, I'll look for a tap with matching threads. Tnx.