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Isolation Diaphragms


Isolation Diaphragms

Kearflex offers a line of diaphragms specifically used for isolation applications. This is where there is a fluid fill behind the diaphragm which transmits pressure to a remote, or "isolated sensor". The sensor can be of any type including strain gauge, piezo, capacitive, inductive and optic.

The important characteristic of the remote sensor is that it is not suitable for exposure for the wetted media. The process media can be corrosive, high or low temperature and can contain solids. The key attributes of an isolation diaphragm are high sensitivity, and the material. The sensitivity allows a very thin diaphragm to pass through the applied pressure with a minimal change. The raw material is matched to the process media, and can be 316L, Hastelloy, Inconel, Monel, or any other material that can be formed into a diaphragm.

Common Types


Ansi B16.5 Process Flange

These are a very common type of flange used throughout the process industry. They bolt into the side of tanks, pressure vessels, and piping systems. The flanges are available in Class 150, 300, 450, and 600, which allow operating pressures up to 1,580 Psi.

Sanitary Style Flanges

Used in the food processing and pharmaceutical industries, the isolation diaphragm provides a sterile sensing interface. These diaphragms include special internal angles that allow natural drainage for in place cleaning and sterilization.

Industry specific surface finishes include electro-polishing, and bio-compatible coatings. These assemblies are installed using standard quick release clamps.


Sandwich Clamp Design

This is a variation of the bolted flange type, except that it is clamped between flanges, or a tank flange interface, and does not include the bolt pattern in the assembly. The advantage of this approach is the assembly is significantly smaller and lighter.


Custom Body Application

Pictured is an isolation diaphragm installed in a custom body which has two ports to allow flush through cleaning. Kearflex can provide this type of assembly based upon a customer design, a clean sheet of paper approach, or a combination of both.


Ansi Flange Cutaway

Cut away view of the ANSI B16.5 Flange assembly. The chamber is filled with a liquid and pressure on the diaphragm creates pressure inside the chamber which is measured by the sense elements. The sensor can be of any type including strain gauge, piezo, capacitive, inductive, and optic.