www.chevyhiperformance.com/techarticles/89678_valve_angles/index.html You should have a good understand with this.
The ports of the angle valve ( Inlet and outlet) are oriented at an angle 90 deg.
The area where a valve closes in the combustion chamber of a four-stroke engine is called the valve seat. During a valve job, this seat is ground at a set angle, usually 45 degrees, for a good seal. In a three-angle valve job, additional angles are ground into each side of the seat angle to ease the transition and improve flow.
where the process require the fluide to be leave at right angleto the direction in which it enters at that time we use angle valve
By shutting off the water supply prior to this valve of course
To regulate the flow of a liquid or gas.
Valve degrees vary accouding to the manufacturer of the engine. Specs are givien for each engine in a manual that displays valve timeing and valve degree of angle. This is importan because the valve angle must match the head angle already cut into the head by the manufacturer. I have seen everything from 12 degrees to 45 degrees and sometimes multiple degrees. It is according as to what you want the valve to do. More top end speed, less top end speed double fire, tripple fire, advance and retard mechanisms and other factors.
6.
Where the easher sits Different engine manufactures use different spec's for their valve angles. There is so much criteria used to determine that angle, it would fill a book. That's why they are called engineer's and we are called grease monkeys.
An angle stop is not intended to control water pressure for most applications. That being said, however, you can control the pressure with an angle stop valve (Aka angle pattern globe valve) while there is flow. As soon as the flow stops, then the pressure will equalise throughout the system. I would suggest using a PRV or pressure reducing valve. This will control water pressure under most all conditions. Source: 2nd year plumber training, Alberta
Shut off valve at the wall? Turn the main water line off and change it. How you change it would depend on what type it is and how it attaches to the pipe.
cam right angle drive needle valve
the valve oerlop increase