Pneumatic signaling still wheezes?

Are instrumentation transmitters that use 3-15 psi analog signals still around?

04/08/2011


Dear Control Engineering: I was reading the article about using smart instrumentation, and it discusses some of the history of field devices, back when everything ran on pneumatic systems. Are pneumatic analog devices still around?

Pneumatic devices have been gone for the most part for quite a while, with the majority replaced by the 1980s. Of course their demise was not all in one fell swoop. The move to electronic analog and digital devices took some time and is probably still not entirely complete. Process instrumentation and control devices like valves, that operate on 3-15 psi are certainly still around, but you will have to hunt for them.

After a few minutes digging around the industrial listings on eBay, I managed to find an old Foxboro liquid level transmitter 13FA1-HK31A5 sold by a company called National Recycling. That should tell you something.

There are companies that still sell new 3-15 psi transmitters, but these are rare too. Here’s a company in Italy that still offers a small selection. There are certainly others if you care to look more thoroughly. More often than not, the pneumatic devices available now are converters that change pneumatic to electronic. Here’s one that changes a Foundation fieldbus signal to pneumatic for a control valve.

Suffice it to say, small delicate mechanisms with diaphragms and leak-prone tubing were not exactly maintenance friendly, so I doubt very many people were sad over the change to electronics. As the article points out, compressed air signals can’t convey much information. An air signal line is good for one signal and that’s it. No diagnostic data, no secondary variables, it’s pretty dumb.

Granted there are still folks out there that want to see trains pulled by steam locomotives, cars with carburetors, and their newspapers set on Linotypes, but the romance of such things gets eclipsed quickly when one has to deal with how maintenance intensive those older technologies are.

If you still use pneumatics and are proud of it, let us know.

Peter Welander, pwelander@cfemedia.com



No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
IIoT grows up; Six ways to lower IIoT costs; Six mobile safety strategies; 2017 Salary Survey
2016 Top Plant; 2016 Best Practices on manufacturing progress, efficiency, safety
2016 Product of the Year; Diagnose bearing failures; Asset performance management; Testing dust collector performance measures
Future of oil and gas projects; Reservoir models; The importance of SCADA to oil and gas
Big Data and bigger solutions; Tablet technologies; SCADA developments
SCADA at the junction, Managing risk through maintenance, Moving at the speed of data
What controller fits your application; Permanent magnet motors; Chemical manufacturer tames alarm management; Taking steps in a new direction
Tying a microgrid to the smart grid; Paralleling generator systems; Previewing NEC 2017 changes
Package boilers; Natural gas infrared heating; Thermal treasure; Standby generation; Natural gas supports green efforts

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
Motion control advances and solutions can help with machine control, automated control on assembly lines, integration of robotics and automation, and machine safety.
This article collection contains several articles on the vital role of plant safety and offers advice on best practices.
This article collection contains several articles on preventing compressed air leaks and centrifugal air compressor basics and best practices for the "fifth utility" in manufacturing plants.
Maintenance Manager; California Oils Corp.
Associate, Electrical Engineering; Wood Harbinger
Control Systems Engineer; Robert Bosch Corp.
click me