Diaphragm Seals for Aggressive Media
A diaphragm seal is a device that is designed to isolate and/or protect a pressure measuring instrument from corrosive, viscous, contaminated or very high temperature process media. The pressure measuring element of the measuring device, and the instrument connection port are filled with a suitable liquid, utilizing state of the art vacuum filling technology, making pressure measurement a direct and simple process.
Pressure, when applied to the surface area of the diaphragm causes it to flex and transfers the pressure through the fill fluid to the attached pressure gauge, transducer, switch or any pressure measuring device for measurement indication.
Aggressive process media can be categorized as follows:
1. Chemically aggressive (corrosive) media with extremely high or low PH levels
2. Erosive media
3. Media that can polymerise and plug in small openings
4. Highly viscous or media with high sediment that can plug
5. Extremely high temperature media
Most often, when these conditions exist, a protective barrier can be efficiently installed to protect the pressure measurement device. The diaphragm seal or chemical seal comes in a variety of sizes and configurations to fit into almost any process installation.
Diaphragm seals can be installed with capillary tubing and can be filled with high temperature rated fill fluid to protect the instrument from excessive heat. NOSHOK diaphragm seals can be installed with pressure gauges, pressure switches, pressure transducers and transmitters, and differential pressure gauges. They offer various materials of construction to offer protection in highly corrosive media and can often supply it with NPT or flange process connections.
