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Ashcroft Diaphragm Seals, Instrument Isolators, Isolation Spools and Rings


Ashcroft diaphragm seals are designed for use with pressure gauges, pressure switches, pressure transducers or pressure transmitters on process applications where (1) process element materials capable of withstanding corrosive effects of certain fluids are not available (2) the process fluid being measured would normally clog the pressure measuring device or (3) the process fluid in the measuring element might freeze due to changes in ambient temperatures.
A diaphragm assembly fabricated of materials that will withstand various corrosive media encountered, separates the measuring element from the process fluid.  Since the space between the diaphragm and the measuring element is solidly filled with liquid, any movement of the diaphragm, caused by a change in the process pressure, will be indicated by the instrument.

Ashcroft diaphragm seals are normally mounted directly to the socket of the pressure instrument.  A flexible stainless steel armored line assembly, is available for mounting the instrument as some point away from the diaphragm seal location to provide easy reading, or to limit the temperature of the instrument.

Diaphragm seals (instrument isolators) with filled capillary line assemblies are another good solution to the problem of hot liquid and gas lines. Due to the small diameter of the flexible capillary, a five-foot line length will usually ensure that the temperature of the instrument connection does not exceed 150 degrees Fahrenheit. This solution is also superior to a siphon on steam service where the water filled siphon might freeze.

Ashcroft Diaphragm Seals come in a wide variety of specifications, materials, pressure ratings, flange classes, process connection types and instrument connection sizes. This enables use in a diverse array of applications. Our diaphragm seals are most commonly used in the process, energy, chemical, water & waste-water, pharmaceutical, and food industries among others. There are literally thousands of applications of which we’re able to meet your industrial needs with over 30,000 product variations in type, connections and materials.

• Line Assemblies

When a gauge is installed on a process line containing hot liquid or gas, one solution to protect the gauge from damage and/or accuracy degradation from elevated temperature is to simply include an extra five feet of capillary between the process media and the gauge. The slow rate of heat transfer through the added capillary and dead-ended process fluid will generally protect the gauge from damage and/or accuracy degradation.

Ashcroft Isolation Rings are designed to provide a cost-effective sensing area / instrument that can monitor pressure exertion. All readings are reliable and accurate. Ashcroft instrument isolators offer the flexibility of instrument removal for calibration, repair, or replacement without shutting down the process flow.

Isolation Rings can be used for the pressure measurement of difficult fluids, tank level indication, long distance pipe pressure for break detection, pump output pressure and signaling to stop pumps or open a by-pass valve. Isolation rings can be used with Ashcroft pressure switches, pressure gauges, pressure transmitters and pressure transducers.

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