Time is constantly working against operating equipment in a plant. Over time, components of the equipment reach the end of their useful lifespan and need to be replaced. Manufacturers go out of business or are no longer producing parts for antiquated equipment. Technology advances and new and improved standardized models are developed, causing components to become outdated or obsolete. Industry standards are revised resulting in non-compliant components. Many processing facilities in the United States were built decades ago and have never been upgraded and maintaining aging equipment can be a challenge as parts for the old equipment are often no longer available or very expensive.

If aging equipment is not managed properly in relation to its expected lifespan, it can result in avoidable safety incidents, or maintenance and reliability issues. Most equipment has a specified life expectancy, and pushing it beyond its useful life can put an operating facility at risk. Some older systems and instrumentation do not have the technology for diagnostics, and therefore, have no ability to query or troubleshoot the operating issue, resulting in extended shutdowns. Additionally, companies may face a loss of production and revenue in the event of mechanical issues with a piece of antiquated operating equipment, systems or instrumentation that causes the process to go offline.

When one Germany-based infrastructure technology company discontinued its popular automation controller in 2017, many of its customers were confronted with the decision of whether to continue operating with the obsolete controller or upgrade to a new control system. For example, a boiler at a petrochemical facility operated on single-loop controllers that were linked together. If the facility continued to run with the obsolete controller, means of future replacement were limited to a used warehouse, salvage dealer, or eBay. The refurbished equipment shop presented options for new controllers to replace the obsolete controllers, however, the configurations were different and incompatible with the existing configuration and linking. Furthermore, if the obsolete controllers were retained and the boiler went offline due to operational issues, there would be longer downtime to resolve the problem since there were few qualified personnel at the facility who could reprogram or troubleshoot the potential issue with the obsolete controllers. This potential operational interruption translated to loss of revenue and greater operating risk while the boiler was down.

The petrochemical facility’s solution was to update the boiler with a new control system. Rather than trying to retrofit antiquated controllers, the company elected to replace the single loop controllers with a safety Programmable Logic Controller (PLC) system while also closing gaps with the current standards. This new integrated system had higher reliability and easier diagnosis if there was a process upset in comparison to its obsolete components, and it brought the facility in compliance with current NFPA standards.

At a separate chemical plant, a company was confronted with the decision of how to replace a failed actuator on the air inlet valve with a process furnace that had been originally acquired from a third-party source. The manufacturer had gone out of business in the 1970s, and the company could not find a replacement-in-kind for the failed actuator or replacement parts to recondition the valve. Instead, they bought a third-party actuator which required a homemade linkage to tie the actuator to the air inlet valve to make it work. However, shortly after being installed, the valve lost its functionality, and the process had to be shut down to recalibrate and adjust the homemade linkage. After multiple iterations of manipulating the valve assembly to regain its functionality, the air inlet valve began to leak, due to its age and frequent cycles of adjustments to the actuator and valve linkage. Maintenance costs increased, as the chemical plant needed to routinely shut down the furnace and production to re-adjust the faulty valve.

Although a valve replacement was certainly necessary by this point, the original 12” valve had not been manufactured to any ANSI standards from a flange dimensional perspective, so no new valve would fit into the current location of this particular valve without piping rework. Significant expenditures became necessary for both a new 12” valve — one that used current technology and control mechanisms matching the original functionality — along with expensive air piping reconfiguration. The maintenance cost and downtime could have been minimized had the obsolete valve and associated actuator been replaced sooner. The upside for the chemical plant was that future replacement of the newly installed standardized valve will be much easier and less costly than the effort that had been required to change out the custom-built valve installed pre-1970.

Older fired equipment can be repaired, inspected and fit for service, but an outdated control system may be unrepairable and unsafe. Refurbished pieces have no guarantee of reliability and are often as old as the part being replaced. Possible failures of any obsolete piece or part could cause an incorrect and dangerous operation with potential damage to the equipment, facility, or people in the area. Delaying an upgrade of aging equipment or replacement of obsolete parts may have costly long-term implications, as additional reconfiguration and solutions may be required if an older unit cannot be easily converted into newer technology. The best solution is to proactively take the opportunity to improve safety by replacing outdated systems and bringing them up to current codes and standards.

A cost-effective first step to address aging equipment is a conceptual level screening checklist that evaluates equipment systematically to identify deficiencies in the components. Facilities may be unaware of serious issues, and this checklist allows companies to make informed decisions and prioritize potential upgrades to aging equipment. This applies to both long-standing operating facilities as well as companies who recently purchased an existing facility, as they may not recognize the condition of all assets and/or older equipment they acquired.

After identifying areas of improvement, a plan can be developed for replacing the obsolete components that are approaching the end of their useful life. This plan should assess the safety concerns, mechanical concerns and operational risks to the facility. It should also include a timeline for how soon the antiquated components should be replaced. The best replacement option is provided with qualities such as reliability and resilience to assure a long lifespan, aligning with regulatory codes and adaptability to future system upgrades installed at the facility.

Entire systems may not necessarily need to be replaced. Not all components of a fired equipment system may need to be upgraded to newer technology, only the critical instrumentation that is dedicated to the safety and operation of the boiler such as the Burner Management System (BMS). If the Combustion Control System (CCS) is well-maintained and does not challenge the BMS, it can be reasonable to assume its reliability and replace only the BMS. Fired equipment systems should be assessed comprehensively and by individual subsystems to determine which antiquated parts should be upgraded to newer technology to ensure dedication to the continued safety and operation of the unit.

Every facility should review its equipment to verify its life expectancy and ensure it is safe and reliable for continued operation. Just because a piece of equipment has been running for 50 or more years does not mean it is safe. Suppose a facility is unable to find replacement parts or utilizes replacement parts sourced outside of the normal supply chain from the manufacturer to adapt to the existing system. In that case, this short-term solution could potentially perpetuate the mechanical and reliability issues. A conceptual level screening checklist can assess the status of aging equipment components, and proactive replacement measures can be taken to create a resilient system going forward.