It is to close the valve(keep it from bouncing/valve float)and keep the lifter on/followingthe cam. This is why race cams with radical lobes need 1000psi springs. The higher the rpm/ heavier the valvetrain the heavier the spring needed.
To retain the valve to the valve spring, could also be called keepers
A valve spring "keeper" or AKA a valve spring "retainer" is used to lock a valve spring to the valve.
Valve pocketing is when a valve is hammering the valve seat.mostly due to miss adjusted valve spring/wrong valve spring/to strong of a valve spring or valve stem to short.Makes the valve seat deeper.
how many positions does a spring offset valve have
you need to compress the spring with a valve spring compressor tool, and then remove the valve keepers, and retainer.
The valve spring is the spring that closes the valve in the engine head after the cam lobe or rocker opens it . If the valve didn't close, many things would happen , the main one being the motor would not fire .
The purpose of the valve spring is to maintain contact between the components in the valve train, so the valve motion will follow the cam profile.
Your engine will probably missfire and you will not have compression in the cylinder that has the broken valve spring because your valve will stay open.
Spring loaded safety valve.
There are valves in the head of the motor. They open to let in air and exhaust out. There is a spring around each one that keeps them closed until the camshaft forces the valve open. Edit: Another way to put it is that the valve spring's job is to close the valve once it's opened by the valve train. The stronger the spring, the quicker it closes the valve and the higher the RPM the engine can operate without 'floating' the valves. The tradeoff is that the stronger the spring, the harder it slams the valve against the seat, reducing each's useful lifetime.
A relief valve is spring loaded valve that when excessive hydraulic or air pressure is applied it pushes the cylinder in the direction of the spring and lets the oil or air pass through and escape via another hose returning to the hydraulic tank or into the atmosphere in the case of air pressure. Without it hydraulic pipes or cylinders would rupture.
A valve spring compressor