VALVE PARTS AND SECTIONS
Valve Disk (Head)
The circular part that operates in the cylinder, provides the air flow by opening and sealing when closed, directly facing the combustion chamber is called the valve disk (valve head). This part, which is exposed to high temperature, pressure and mechanical impacts, must be durable and of sufficient wall thickness. Disk wall thickness cannot be less than 0.8mm after grinding.
Valve Neck (Neck)
The part where the valve disk and the valve stem meet is called the neck, which is filled and curved to resist bending and breaking.