I doubt it is welded to the tank but there should be one somewhere around the water heater inlet or outlet to help balance the cold and hot water system.
Cold water inlet valve water heater.
For more information see water heater leaking from the top.
A cold water inlet valve often identified by a blue handle feeds cold water from the main supply into the water heater.
If the valve that delivers cold water to your tank has gone bad it will drip water onto your tank.
If it doesn t the valve most likely needs to be replaced.
Attach the red fitting to the hot water outlet with the arrow pointing away from the water heater.
All are easily fixed.
Both have arrows showing the correct direction for installation.
So the first thing that you need to do is to check the cold water inlet pipe.
If the valve itself which sits higher up on the pipe has gone bad it will drip water down the pipe and onto the top of your water heater.
The cold water inlet valve allows the flow of cold water into the heater.
Your cold water inlet valve is where cold incoming water from your home s main water line enters your water heater.
You need to look for a ball valve or gate valve which will allow you to turn off the water.
Frequently the cold water inlet valve sits directly above the heater.
Water leaking from the bottom.
This ball valve is responsible for cold water inlet to the pipe.
The cold inlet or hot outlet pipes may be loose the t p valve may have failed or inlet valve may be leaking.
Turning it off will stop the water from entering the tank when you need to carry out maintenance repairs or to drain the tank in preparation for a replacement.
Attach the blue coded fitting to the cold water inlet with the arrow facing into the water heater.
If you believe you have a leak near the top of your electric water heater it could be one of a few things.
You can attempt to replace the valve yourself following these instructionsor have a professional replace the valve.
Tighten using two pipe wrenches or adjustable pliers.
First try tightening the valve to see if that stops the leaking.
The hot water outlet pipe also has a valve that will shut down all hot water leaving the water heater.