Diaphragm Seals

In order to isolate the measuring elemtent of pressure gauges, pressure switches and electronic pressure transmitters from corrosive, vicous and sedimentary process fluids, diaphragm seals are placed in between the measurement point and the instrument. Diaphragm seals must often be made of special high-strength materials.

Diaphragm seals are manufactured to DIN or ANSI standards.

Depending on model, following materials are available for the wetted parts:

Stainless steel AISI 316
Stainless steel AISI 316 with PTFE coating
Monel 400
Hastelloy C276
Hastelloy B2
Tantalum
Icolloy 825
Inconel 600

Please have a look at our brochure "Introduction to Diaphragm Seals" .
There you find recommendations as well as information about material resistances.

Models

Model 04.1B0 - 04.1BS
Skizze Druckmittler 04.1B0 - 04.1BS
Pressure ranges from 0...0.1 bar to 0...40 bar and vacuum -1...0 bar
Process connection: thread
Can be dismounted for cleaning

Model 04.1AS - 04.1A0

Pressure ranges from 0...400 bar to 0...600 bar
Process connection: thread

Model 04.111
Skizze Druckmittler 04.111
Pressure ranges from 0...6 bar to 0...250 bar
Process connection: thread
Can be dismounted for cleaning

Model 04.3A0 - 04.3B0
Skizze Druckmittler 04.3A0 - 04.3B0
Pressure ranges from 0...1 bar to 0...250 bar and vacuum -1...0 bar
Process connection: flange
Flanged connection with passing through holes
Available with PTFE coating

Model 04.600
Skizze Druckmittler 04.600
Pressure ranges from 0...1 bar to 0...40 bar and vacuum -1...0 bar
Process connection: flange
Available with PTFE coating

Model 04.500
Pressure ranges from 0...1 bar to 0...400 bar and vacuum -1...0 bar
Process connection: flange
Flanged connection with passing through holes
Flush diaphragm

Model 04.400
Skizze Druckmittler 04.400
Pressure ranges from 0...1 bar to 0...40 bar
Process connection: flange
Flanged connection with passing through holes
Faced diaphragm
Economic execution for special materials
Available with PTFE coating

Model 04.MINI
Skizze Druckmittler 04.MINI
Pressure ranges from 0...1 bar to 0...400 bar and vacuum -1...0 bar
Process connection: thread
Compact and economic

Model 04.SAN
Skizze Druckmittler 04.SAN
Pressure ranges from 0...1 bar to 0...40 bar
Process connection: as per DIN 11581, SMS681, RJT/APV, IDF/ISS
Perfect for hygienical and food applications
Surface finishing 0.76...0.38 µm

Model 04.AL
Skizze Druckmittler 04.AL
Pressure ranges from 0...1 bar to 0...40 bar
Process connection: as per ISO 2852
Clamp 1 1/2", 2", 2 1/2"
Surface finishing 0.76...0.38 µm

Model 04.R00
Skizze Druckmittler 04.R00
Pressure ranges from 0...6 bar to 0...250 bar
Process connection: to be in-lined welded or flanged connections

Model 04.367
Skizze Druckmittler 04.367
Pressure ranges from 0...40 bar to 0...400 bar
Process connection: thread, flush membrane
Flush diaphragm with threaded connection

Pressure ranges from 0...160 mbar to 0...160 bar
Process connection: "Wafer" diaphragm seal (DIN or ANSI)

Technical information

Diaphragm seals are designed to measure the process fluid pressure when the process fluid temperature is non-compatible to the instrument sensing element, when the process fluid may corrode the inner parts of the measuring instrument in contact with the fluid, when the fluid is highly viscous or it contains solid suspensions, and when it solidifies at temperature changes.
They are also used for long-distance pressure fluid transmission and measurement allowing to isolate dangerous fluids from the operating areas.
They can be directly connected to the indicating instrument or through a capillary.

The diaphragm seal operating principle is based on the fluids non-compressibility. The separation from the process fluid is optained from an elastic diaphragm sealed to the diaphragm seal body. In our factory, the inner chamber between the deaphragm and the bourdon tube is at first evacuated, than filled with properly degased fill-fluid. At this point the system is able to transmit the mechanical stress produced by the process fluid on the diaphragm to the bourdon tube. Any air bubble in the circuit must be avoided as it could affect the right system operation. For this reason we recommend to buy diaphragm seals together with the pressure reading instrument in one order.

Information about Diaphragm Seals