A diaphragm seal is a device designed to isolate 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 utilising 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 transfer 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 categorised as follows:
- Chemically aggressive (corrosive) media with extremely high or low PH levels
- Erosive media
- Media that can polymerise and plug in small openings
- Highly viscous or media with high sediment that can plug
- 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 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 as well as differential pressure gauges.
The company offers various materials of construction to offer protection in highly corrosive media and can often supply it with NPT or flange process connections.