Controlling the compressors

Air Liquide Large Industries U.S. LP is part of Air Liquide Group, which produces industrial and medical gases and is headquartered in Paris. In the U.S., Air Liquide maintains more than 125 production facilities and 700 customer installations spread across some difficult to reach geographies. Before 2002, The U.S. company used a legacy vibration program that was inconsistent in its application of technology and wasn’t producing the desired results.

Late in 2002, Air Liquide partnered with Rockwell Automation to provide vibration analysis services to 32 plants on a trial basis. The program expanded quickly in early 2003 to include vibration monitoring at 107 primary production facilities. In August 2004, Air Liquide recognized the need to expand its predictive maintenance (PdM) program to include oil and infrared analysis, and again partnered with Rockwell. Air Liquide’s needs and aggressive long-term strategy didn’t leave time for incremental continuous improvement. The key program objectives included:

• Transitioning from legacy systems to state-of-the-art information solutions
• Understanding how reliability affects customer relationships and profitability
• Recognizing the need for uniformity of predictive technologies
• Leveraging technology in geographically challenging areas
• Analyzing results and setting goals for improvement

Transitioning from legacy systems
Before 2000, maintenance and reliability functions were decentralized as was the responsibility for approximately 100 plant sites throughout the U.S. Since that time, Air Liquide in the U.S. has centralized these functions under a new maintenance department and regional reliability centers. The new department deployed several new systems including a maintenance management process, a new computerized maintenance management system (CMMS) and preventive maintenance programs. Once these basic systems were in place, the department turned its attention to its predictive maintenance programs.

Many of the sites used vibration, infrared and oil condition monitoring, but because no corporate standard existed for applying predictive technologies, individual managers had great discretion. As a result, applications were inconsistent and couldn’t be integrated. Similar data was taken at different frequencies with different tools and at different locations for like equipment. Therefore, data and reports varied in format and detail, and information couldn’t be compared and analyzed across similar equipment.

Because a company-wide CMMS didn’t exist when these individual programs were established, predictive findings couldn’t be linked to traceable work orders. Compliance of corrective actions versus predictive findings was unknown.

Several dozens of plants eventually coalesced around a common vibration service provider, but the program had several problems. The contractor owned the data it collected. While the contractor provided some standard reports, Air Liquide had to pay for ad hoc analysis it could have performed itself. But, more importantly, the contractor had only one office in the far southeast corner of the U.S. Given Air Liquide’s vast geography in the U.S., more than 80% of the costs the contractor charged were incurred for travel to the plant sites. Air Liquide knew there had to be a way to get greater value.

By 2001, the infrared scanning program was probably the closest to being national. Electrical standards had been developed and applied, and an internal resource was used for data collection and report writing. While the program was effective, it was used primarily for electrical devices and didn’t include any applications to identify process, fixed equipment or rotating equipment problems. And given Air Liquide’s geographic dispersal and the travel it required, having a single resource dedicated to the program didn’t seem viable in the long term.

Although it was implemented at several sites, oil condition monitoring was probably the least used of the technologies. There seemed to be significant potential benefits to increasing its use.

Customer relationships and profitability
Many of Air Liquide’s products are commodities. The company president once remarked, “Winners and losers in our business are determined by those who can provide the most reliable product at the lowest possible price … and our maintenance and reliability programs have a huge effect on both success factors.” Whether it’s nitrogen, oxygen, hydrogen, steam or electricity, customers want all of the product they want, when they want it, and they don’t want to hear excuses why they can’t have it.

This places a premium on our unit availability and equipment reliability. Not only must there be robust maintenance programs to ensure high reliability, but also a way to see problems far in advance so arrangements can be made for equipment downtime when customer demand is low. That’s why predictive maintenance programs play such a large role in Air Liquide’s reliability strategies, which play a significant role in its business strategy.

Before the 1990s, Air Liquide was primarily an air separation company that produced oxygen, liquid argon and both liquid and gaseous nitrogen. These air separation units could back up production to our largest gas customers by storing large quantities of liquid nitrogen and oxygen. We could then vaporize the liquid and sustain several days of downtime in the event of an interruption in service. The primary strategy for these products was to reduce our mean time to repair (MTTR). This meant focusing on stocking spare parts and having resources ready to react to get a unit running again before the “liquid ran out.”