Does a submersible pump have a built in check valve?

In this regard, where do you put the check valve on a submersible pump?

In submersible pump applications, the first check valve should be installed directly on the discharge head of the pump or maximum one pipe length (20 feet) above pump. Water pumped and flowing through a piping system has a certain amount of energy (weight x velocity).

Likewise, do I need a check valve on my pressure tank? You need a check valve at the pump discharge and another above ground before the pressure tank. The one at the pump keeps the pipe full so you don't have a lag when the pump starts (no water hammer). You have water immediately.

Keeping this in view, where is a check valve located?

Check valves are found everywhere, including the home. If you have a sump pump in the basement, a check valve is probably in the discharge line of the pump. Outside the home, they are found in virtually every industry where a pump is located.

How do I know if I have a bad check valve?

Failing valves will emit warning signs at the first hint of trouble. For example, failing check valves will start to vibrate and even lose some internal parts when problems begin to arise. Other symptoms of check valve failure include reverse flow and excessive component wear and damage.