Claire Christian Valves April 10th, 2019 - 14:31:40
Needle Valves are used whenever control or metering of steam, air, gas, oil, water or other non-viscous liquids is required. This means they are used in almost every industry over a massive range of applications. Swagelok Valves are all factory tested with nitrogen at 1000 psig (69) bar to ensure that seats have a maximum allowable leak rate of 0.1 stdcm3/minute, and shell testing is performed to a requirement of no detectable leakage with a liquid leak detector.
The original principle of the operation of a valve was ingeniously basic. Operators were able to process the sometimes corrosive and abrasive water, generally caused by flooding, but the use of a "pinching" action that pressed down on a component now known as an elastomer sleeve, restricted the flow of water. This innovation was the foundation for the sophisticated Air operated Pinch Valves of today.
In standard valves, when it is given a command to open to a certain point, there is no feedback to verify that the valve has opened to that position. With a valve positioner, the command is given and the valve positioner reads the opening, verifying the position and readjusting until it gets it to the exact position needed. This allows for great precision in the adjustment.
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.
We have come across pipelines all around that efficiently transport vast amounts of liquids and gases (collectively called as fluids). But they need a regulating body to decide the amount of the flow and to start and stop the flow for their efficient working. Here, valves come into picture and are the regulating body that control the flow rate and act as a switch to start and stop the flow.
If the sealability is not good or the strength is not intensive, the parts may be destroyed. Thus, it will result in the economic loss in different degree, such as transporting the poisonous, explosive or corrosive fluid. And even it will lead to the serious accident. In order to ensure the sealing and strength of the valve, the manufacture should not only obey the related standards to design and produce the product but also should properly select the material.