Answer:
Control valves are used in many processes to control flow, pressure, temperature or other variables. The type of valve used will depend on the size of the pipe, the overall pressure that the system operates, the flowing media, process conditions, and other factors.
Also
A control valve is a valve used to control fluid flow by varying the size of the flow passage as directed by a signal from a controller. This enables the direct control of flow rate and the consequential control of process quantities such as pressure, temperature, and liquid level.
<u><em>Hope this helps :)</em></u>
<u><em>Pls brainliest...</em></u>
This so that astronauts can study the chemical atmosphere of a planet better. We will know whether the atmosphere will be toxic to our lungs or not. Astronauts need to have a deeper understanding of a planet before going there. For example, before going to the Moon, humans relatively understood what the Moon had no atmosphere, so if you walked in there like you walk down here on Earth, you'd die to shortness of breath. We understood that before landing because these different telescopes help us put light rays not within the visible light spectrum into visible light in images. Hope this helps ;)
Answer:
Concave lenses are used in eyeglasses that correct myopia or nearsightedness.