According to the operational features of your ratcheted water heater safety valve, when the pressure in the system rises above the set pressure, water will start dripping from the discharge nipple of your valve. This is an entirely normal condition that also shows that you are safe, and is not a cause for complaint. Under the circumstances, the thing to do is to attach an 8-mm tube to the discharge nipple and connect it to a drain.

Water drop main safety !

It has been manufactured for the purpose of controlling the system (by switching on or off) against the possibility of calcification or blockage with lime, sand or pebbles that might accumulate in time.