Spring loaded safety valve.
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.
A valve spring compressor
The purpose of the valve spring is to close the valve when the cam has finished pushing it open to allow fuel/air in or exhaust gases out. The spring is held in place at the top of the valve by a split-collet, like 2 halves of a cone, and also sits against the outside of the cylinder head. The spring is compressed when the cam on the cam shaft pushes it down, and as the cam moves away, the spring forces the valve shut again.
A valve spring compressor is used to remove collets in a car. The tool compresses the valve springs in the cylinder head of the car allowing the collets to be removed.
KD Tools Valve Spring Compressor 3087