'92 CC Plumbing Q3 - Water Pump Relief Valve

I had to remove my water pump to replace a frozen pump head. The pump has the expected 2 hose connections: in-feed from the tank and out-feed to the house. Someone also installed a "T" on the high-pressure out-feed and installed a 70-psi pressure relief valve (see photo). Connected to the valve was a 2-foot length of tubing which was just sitting on the tank - not connected to anything. If this were stock, I would expect the tubing to connect to a drain bulkhead in the floor or feed back into the tank.

Q1: Is this relief valve factory stock and if so, where should the tubing connect?
Q2: Is this valve necessary? I assume someone is worried that if the pressure switch fails closed and the pump runs constantly the house plumbing will be over-pressured and fail?

Thanks
Attachment 10384