What are Diaphragm seals?
Diaphragm seals, also known as diaphragm pressure seals, are specialised instruments used to protect pressure measuring instruments, such as pressure gauges and transmitters, from corrosive, high-temperature, or viscous process fluids. They consist of a flexible diaphragm made from materials resistant to the process media, sealed between the process fluid and the pressure measuring instrument.
Diaphragm seals find applications in various industries, including chemical processing, oil and gas, pharmaceuticals, and food and beverage, where accurate pressure monitoring is essential, but conventional pressure instruments may not withstand harsh process conditions. They play a critical role in maintaining measurement accuracy and protecting valuable pressure instruments in challenging industrial processes.
How Does a Diaphragm Seal Work?
A diaphragm seal works by isolating the pressure measuring instrument, such as a pressure gauge or transmitter, from the process fluid it is measuring. It consists of a flexible diaphragm made from a material resistant to the process media, typically stainless steel or other corrosion-resistant materials.
Here's how a diaphragm seal works:
Installation: The diaphragm seal is installed between the process fluid and the pressure measuring instrument. It is connected to the process line through a threaded or flanged connection.
Pressure Transmission: When the process fluid exerts pressure on the diaphragm, it flexes or deforms accordingly. This deformation transmits the pressure to the fill fluid inside the diaphragm seal.
Fill Fluid: The fill fluid, often a suitable liquid or oil, fills the space between the diaphragm and the pressure measuring instrument.
Isolation: The diaphragm and fill fluid act as a barrier, preventing direct contact between the process fluid and the pressure-measuring instrument. This isolation protects the instrument from corrosive, high-temperature, or viscous process fluids, which could otherwise damage the instrument.
Accurate Measurement: The pressure in the fill fluid is then transmitted to the pressure measuring instrument, allowing it to accurately measure the process pressure while being shielded from the adverse effects of the process fluid.
What do you use a diaphragm seal for?
Diaphragm seals are utilised in various industrial applications to ensure accurate pressure measurement while protecting pressure instruments from challenging or harmful process conditions. They find widespread use in industries like chemical processing, petrochemicals, pharmaceuticals, and food and beverage, among others.
In corrosive environments, diaphragm seals shield pressure-measuring instruments from direct contact with aggressive substances, preserving their accuracy and prolonging their lifespan. High-temperature processes, such as metal smelting or steam systems, benefit from diaphragm seals' ability to prevent heat-induced damage to pressure instruments.
Viscous media, found in industries like pulp and paper manufacturing or food processing, can lead to clogging and damage, which diaphragm seals prevent. Additionally, these seals maintain sanitary conditions in hygienic applications, ensuring accurate pressure measurement without compromising product purity.
In offshore, marine, and hazardous environments, diaphragm seals protect pressure instruments from exposure to saltwater, harsh marine conditions, and potentially explosive materials, maintaining safe and reliable operations. Overall, diaphragm seals play a critical role in achieving precise pressure measurements while enhancing the durability and reliability of pressure instruments in challenging industrial settings.
How Much Do Diaphragm Seals Cost?
Plant and Control Instrumentation Pro have diaphragm seals starting at a low $159.50.