The valve seat performs two functions: it provides a seal for the valve in the combustion chamber, and it provides a cool surface to carry heat away from the valve. most valves use a seating angle.

This is science by the way which of the following is an example of an environmental pressure a. the air pressure in the atmosphere b. a lake that is gradually running out of water c. a fight between two members of the same species d. breeding between two members of the same species