Regarding PID instruments
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For the instruments in a PID system, the PT (pressure transducer) is connected to pipes as well as a diaphragm – what is the purpose of that? Some pipes have PT connections, while others do not. Why, what is its function?
What’s going on? Is it the pressure transmitter? You are referring to a pressure transmitter with diaphragm capillary tubes, right? In this setup, the medium under measurement does not come into direct contact with the gauge; instead, pressure is transmitted through the silicone oil inside the diaphragm capillary tubes. Additionally, it is possible to extend the gauge to another location for installation in areas where reading it is inconvenient.
Thank you, I don’t understand it either. I’m just starting to work with PID, and I noticed that some transmissions have diaphragms while others don’t; I don’t know why or what purpose they serve.
This post was last edited by ylb913 on 2015-11-3 at 10:02. It provides direct anti-freezing, anti-condensation, and anti-crystallization protection thanks to the diaphragm. For those without a diaphragm, an isolation fluid needs to be injected to prevent freezing.
Whether a diaphragm is used or not is determined by the production medium at the PT installation site. Diaphragms are generally installed to prevent freezing, condensation, and crystallization.
Different media require different selections; diaphragm type prevents blockage and corrosion
It mainly serves to prevent corrosion and provide insulation; no additional instructions are needed if none have been provided.
Those with running-in indicate diaphragm-type pressure transmitters, which are mainly used for media that are highly corrosive, viscous, or contain solid particles. The one that isn’t included is a regular pressure transmitter.