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Tipping Points – When to Plan for Retrofits and Upgrades

With Rene Alquicer, Ipsen’s Southwest Region Sales Manager, and Tom Sutherland, Ipsen’s Southwest Region Sales Engineer

What does “normal” wear and tear look like?

Maybe it’s a broken element that needs to be replaced or a dented hearth from a dropped part. Maybe it’s cleaning up the furnace from brazing residue on a regular basis.

“It depends,” explained Rene Alquicer. “There are no definitive black and white answers, particularly when it comes to wear and tear. Even though you might think it would be obvious, ‘normal’ wear and tear is often subjective.”

It’s common knowledge that regular maintenance on a furnace can significantly extend its lifespan. Routine inspections, oil changes in the pumps, retightening and replacing loose or damaged elements, replacing leaky seals and lost nozzles, or repairing mounts and supports are all typical maintenance tasks for furnaces that are used every day.

But there does come a time when those issues start to pile up. How does an owner, operator, or maintenance team know that it’s time to make an investment in a retrofit, upgrade, or replacement furnace? More importantly, what makes a retrofit different from routine maintenance?

“In general, a retrofit is a restoration, either small or major, that makes a significant improvement within a furnace,” Alquicer explained. “Whether you’re replacing a whole hot zone including plenum, or a PLC control system – from just a few key components all the way to a whole new cabinet… Whenever engineering needs to be involved, that’s going to be considered a retrofit, not just a repair or part replacement.”

Warning Signs

In a world where significant equipment investments require a capital budget plan, it rarely makes sense to continue operating poorly functioning or obsolete furnaces without building a budget case for a retrofit or replacement.

“Honestly, some of our customers will choose to plan ahead when they start to project the consequences of downtime affecting their throughput, while others will wait until the consequences have happened to do anything,” Tom Sutherland observed.

Being prepared to act when a retrofit is needed always starts with a well-tracked maintenance log and regular visual inspections. “How damaged does the hot zone look? Are you keeping it in good shape, or are you running processes until an issue occurs? No matter what, it’s only a matter of time before an issue occurs, though that time can be longer or shorter based on the routine services provided and the processes that are being run,” Sutherland explained.

Inspections and regular service are important to maintain a clean and functioning chamber and a hot zone free of dirt and debris. “Whenever there’s loose debris within the chamber as the gas is circulated in the chamber at high velocity during a quench cycle, that debris can start to act like a sandblaster, possibly eroding the hot zone, or potentially shorting out the blower motor,” Sutherland noted.

Photo of debris in a vacuum furnace hot zone
Example of hot zone debris
Photo of a vacuum furnace hot zone damaged from an air leak
Rusted hot zone plenum caused by excessive air leaks

Beyond the hot zone and the pressure vessel, operators must also keep an eye on other elements that affect the processes run within the furnace. Water systems, gas systems, and PLC controls each have their own set of recommended periodic inspections to prevent failure events.

Monitoring and regular maintenance on a new furnace are as important as doing the same for furnaces that are years or decades old. Some processes may reveal a need to modify the furnace in order to protect the integrity of the hot zone and other vital furnace components.

For example, “when there are problems with the pumping systems caused by brazing material or outgassing, and when booster pumps get clogged, that may indicate the need for a required modification to accommodate the addition of a filter,” Alquicer said.

Planning Ahead to Avoid Downtime

“Part of our job is to understand what our customers’ needs are, then help them project, budget, and explain the need for service or equipment that will help solve problems,” Alquicer explained.

“A part of that is reviewing lead times for equipment availability, while also understanding how their internal processes will affect those timelines. While time between order and delivery might fall between six months and a year for a given piece of equipment, that timeline may be extended based on the process of getting approval for the expenditure.”

This is why it’s so important to monitor and assess the need for retrofits or replacement. Waiting for a catastrophic failure can have significant costs, not just when it comes to repair, but also when it comes to unexpected lost production.

Hot To Go

When keeping an eye on the hot zone, you might start to see signs that there’s a need to plan for a replacement just by inspecting the insulation and the hot face.

“If you see the CFC hot face starting to thin out, which you can test for by pressing on it and seeing if it easily bends, you might be able to put another layer of CFC over it to extend the life a little while, but once the CFC blows out there is no protection to the felt which will rapidly deteriorate. Once the insulation goes, you get hot spots and uniformity problems,” Sutherland explained.

Photo of a vacuum furnace door with CFC deterioration
Example of CFC deterioration
Closeup photo of a vacuum furnace door with CFC deterioration

“Maintenance teams should be paying close attention to the areas below the hearth, because that’s where things fall and where damage to the CFC most likely occurs first. This debris can affect both the parts being processed and the door seal.”

Data can also tell the tale of a hot zone in need of a replacement. “Have you noticed that your furnace is taking longer to reach vacuum? Are you seeing clean cycles, or is the hot zone saturated with brazing material? Are the supports falling down? Are there cracks in the welds? There are many indicators that can give you an idea about what’s going on in the hot zone,” Alquicer suggested.

Adding Functionality

Sometimes retrofits are needed to expand the functionality of the furnace to meet the changing demands of the customers.

“We’ve changed graphite hot zones to all-metal hot zones. And sometimes a customer receives a new furnace, but a process indicates a need to add a component to work properly,” Alquicer recalled. “One customer wanted to add a cooling fan to a furnace so that they could improve their processes and overall cycle times.”

And sometimes it comes down to making older furnace PLC systems digitally compatible with newer systems. “When customers want to move from an older 500-series PLC to a newer CompactLogix system, that would translate into new hardware, new programming, new HMI… It requires engineering attention,” Alquicer explained.

“A controls retrofit is not quite as easy as replacing a graphics card in your personal computer. Controls upgrades are made for many reasons including cyber security concerns, improved temperature and vacuum control, improved visualization and recordings of thermal processes, accuracy improvements for adherence to AMS2750 standards, and SCADA connectivity compatibility, just to name just a few,” Sutherland added.

Time to Change

There comes a time when even a retrofit doesn’t make sense anymore. While a new hot zone can make a big difference, the remaining systems and functions retain their ages and their quirks. Eventually, those too show signs of wear.

“When you start to notice issues with uniformity or your process times are taking longer, when you’re not able to get good results while processing larger loads, or when your calibration numbers aren’t meeting spec, those can indicate issues that go beyond the hot zone. They may indicate vessel or water system problems,” Sutherland said.

While a hot zone is being replaced, Ipsen encourages operators to test the thickness and condition of their vessel with an ultrasound device. These tests are typically recommended to begin after the furnace has been in service for five years. “When you start to see vessel sections overheating, find water incursion or rust, they may indicate that the water isn’t circulating properly,” Alquicer suggested. “How well you’re treating your water systems has a significant impact on the life span of your furnace.”

As a furnace starts to see more downtime, when the throughput isn’t keeping up with demand, when uniformity isn’t consistent, and as demand for new processes from the heat-treatment department occurs, a serious discussion about a replacement needs to happen. “A new furnace is going to have a fraction of the downtime that a fifteen-year-old furnace would have. They can offer significantly more reliability, with an opportunity to increase capacity and functionality, which could help gain market share for the company,” Sutherland added.

“Also, customers may consider replacing off brand or aging furnaces to reduce the number of spare parts needed, while reducing technical acumen for maintenance and operation personnel by having equipment with the similar controls and maintenance components.”

  • Difficulty achieving part uniformity
  • Multiple systems require retrofitting
  • Functionality doesn’t meet demand
  • Reduced throughput
  • Fails to meet certification standards
  • Increased downtime
  • Pressure vessel deterioration or damage
  • Multiple leak issues
  • Spare part obsolescence
  • Extensive rust/damage to water system

If you have questions about the condition of your furnace, reach out to Technical@IpsenUSA.com, or send an email to Sales@IpsenUSA.com to inquire about new equipment.