Stainless Steel Transmitter Housings for Corrosive Environments

Recently, one of my RSS feeds alerted me to a new Micro Motion 2400S transmitter packaged in stainless steel for the ELITE Coriolis flow and density meter line. This 316L stainless steel packaging is:

Rated to IP66 and IP67, the corrosion resistant stainless steel housing is ideal for applications where instruments are subjected to regular caustic wash-downs, which are typically found in the food, beverage and life science industries. The 316L construction is also ideally suited for marine and offshore environments.

I caught up with Emerson’s John Martin, a Food & Beverage industry manager for the Micro Motion family of products. I wanted to get the story behind the design of this product.

For those that have never been inside a food & beverage or pharmaceutical manufacturing process, John shared how you’ll be struck by the bright, shiny silver look you see around the process. Hygienic standards are paramount in these industries and a mild caustic (e.g. sodium hydroxide) is often used to wash down the processing equipment. Standard painted-aluminum transmitter housings do not do well in this caustic environment. This new 316L stainless steel housing allows the transmitter to be integrally mounted with the Coriolis meter and provides a local display at the measurement point for the operations personnel.

John noted that normally, transmitters with aluminum and painted-aluminum housings had to be mounted remotely, in stainless steel enclosures or control rooms, to avoid the corrosive environment. This installation method meant more engineering and installation costs.

This 2400S transmitter supports DeviceNet and Profibus DP communications. These are common digital bus communication protocols used by PLCs and other automation systems like Emerson’s DeltaV system. Across two wires, these transmitters communicate process and diagnostic information back to the controllers. From the press release:

The result is that one instrument can provide flow, density and temperature measurements, eliminating the need for multiple sensors and the wiring/configuration costs associated with them. In addition, digital communications unlock instrument diagnostic information, such as drive gain, meter verification and other alarms.

John also shared with me that other industries like offshore oil and gas and other marine environments have corrosive environments caused by saltwater and salt in the air, making them good candidates for this stainless steel transmitter housing.

I do know from my days back as an engineer working on offshore Gulf of Mexico oil and gas platforms, that we put the instruments with painted aluminum housing inside 316 stainless steel junction boxes to protect them from the corrosive, salt-air environment. This packaging option might have reduced the size/number of junction boxes required.

Update: I just saw a Twitter “tweet” from @timalosi who reminds me:

there is more to hygenic than stainless. draining is much more important. the Housing is just for looks

Tim, point taken and all in 140 characters or less!

Posted Wednesday, August 13th, 2008 under DeviceNet, Food & Beverage, Life Sciences, Measurement, Oil & Gas, Profibus.

One comment so far

  1. This is why we put almost all of our transmitters in the I/O cabinet to reduce the equipment in the clean space.
    http://www.spec-eng.com/blog/

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