Edwina Dorsey Valves April 14th, 2019 - 12:35:05
Ball valves are usually quarter turn valves (as we turn the lever by 90 degrees to start or stop the flow) and use a hollow, perforated and pivoting ball that is also called as a floating ball. It is through this valve that the flow of fluids takes place. When the lever or handle is turned to 90 degrees, the hole of the ball gets aligned with the pipe opening and starts the flow. When again the lever is turned by 90 degrees, the hole turns around and the ball blocks the opening of the pipe thus causing the flow to stop.
Valves are mechanical devices that obstruct pipes or passages of liquids and gases either wholly or partially to control the flow rate as required. In our lives we come across many valves daily, but might have never noticed them. The taps that we open and close to control the flow of water is a valve. The regulators that we use to control the flow of gas from our gas pipelines are also valves. There are gas control valves in our cookers too. These valves are not limited to man-made things, but are found naturally and that too in our bodies. Our heart has valves that help in regulating the flow of blood in our body.
Added advantages of manual pinch valves include their ability to effectively control the flow of corrosives and abrasives. In addition, there is the lack of contact between any metal part of the valve and the transported material which is a major asset in circumstances where the purity of a product is a high priority. The versatility of the valve is displayed in its ability to handle waste-water, slurries, pulp, powder and pellets, as well as applications in medical and pharmaceutical processes.
This is a valve that plays a major role in many areas of industry, including instrumentation and flow control processes. The operational environments will, on occasions, be offshore in extreme, adverse conditions such as oil and gas exploration and extraction processes. The quality and reliability of a manual pinch valve is something that can make a significant difference to an application of this nature.
Valves are either made of plastic or metal and can be controlled either by handles, levers, pedals and wheels or can be controlled automatically. Generally, the exterior parts are either metal or plastic and are called seat and the inner part generally has plastic and rubber valves for an effective control of the flow of fluids. Body is the inner part of the valve that fits on the seat and controls the flow by opening and closing either partially or wholly depending upon the requirement of the flow rate.
The last one is the valve type and sizing. Over-sizing of valves sometimes occurs when trying to optimize process performance through a reduction of process variability. Over-sizing the valve may hurt process variability in two ways. First, the oversized valve puts too much gain in the valve, leaving less flexibility in adjusting the controller. Best performance results when most loop gain comes from the controller. The second way oversized valves hurt process variability is that an oversized valve is likely to operate more frequently at lower valve openings where seal friction can be greater, particularly in rotary valves.