Wafer Check Valve, or non-return valves, allow water or other material to flow in only one direction, and stop the material from flowing in the opposite direction. They are installed in pipe lines and do not require any activation from outside. Instead, they sense when the material in the pipes is beginning to move in the reverse direction and plug up the pipe to prevent the material’s movement.
1 Place the cylinder head on a solid work bench. Remove the valves from the cylinder head by compressing the valve spring and removing the retainer clips.
2 Insert a dial bore gauge into the valve guide. The Globe Valve guide is a tube or cylinder into which the valve stem is inserted and rides up and down as the valve opens and closes. Measure the valve guide diameter using the dial bore gauge.
3 Measure the valve stems of the valves that will be used in the cylinder head with a micrometer.
4 Subtract the diameter of the micrometer reading of the valve stem from the dial bore gauge diameter reading of the valve guide. For example, if the dial bore gauge reading of the valve guide is 0.342 inch and the micrometer reading of the valve stem is 0.340-inch, is the valve guide clearance is 0.002 inch.
The article comes from Knife Gate Valve.