Executive Summary
Many industries, including metalworking, mining and heavy machinery, can benefit from replacing conventional hydraulic fluids with fire-resistant hydraulic fluids. However, adoption of fire-resistant hydraulic fluids is sometimes limited by cost, lack of education, availability and performance concerns. Some readers point out that legislation would push more widespread adoption, and that the safety benefits could justify new policies. While most readers agree that safety is the top benefit of fire-resistant hydraulic fluids, other qualities that justify the extra cost include longer lifespan, better wear performance and better heat transfer and cooling capabilities.
Q.1 Fire-resistant fluids for mining and, in general, for off-road heavy equipment, have demonstrated that they can be profitable in terms of safety and productivity. But the use of these fluids is not as widespread as it should be. Please describe what could be the reasons that impede taking advantage of this technology.
It is mostly cost and incompatibility of some of the fire-resistant fluids. Fluid conversions can be difficult, time consuming and expensive.
Misunderstanding of the use and maintenance of these fluids results in potential applications being supplied with conventional hydraulic oils.
Increased cost is clearly the No. 1 reason. Lack of strong legislation to drive the change. Best-in-class hydraulic fluids are not well known by the industry that focuses too much on fire-resistant hydraulic fluids and not other technologies.
Lack of knowledge/information for the people using or ordering lubricants, and the problem of keeping this type of fluid from elevated moisture content.
In most cases, customers feel if they don’t have to have a Factory Mutual (FM) approved fluid, they are good to go with standard mineral oil types. Another reason is some see it as more expensive than conventional, but nowadays that is no longer the case. If mandated in an application, they will use it to meet insurance needs, otherwise, not so much.
Pricing. So many in these industries have a hard time going from a straight mineral oil to a fire-resistant fluid. You have to educate them on the safety and protection these products offer.
Cost to benefit ratio (competing metrics from competing departments).
1.) Most of the fire-resistant fluids are ester-based fluids. In mining or off-road heavy equipment, they are used in very dusty and humid environments. So the mining and off-road maintenance crew always see water-based fluids can serve the purpose of rough use and handle effective usage to reduce the cost of buying costly fire-resistant hydraulic fluids. 2.) Preservation and storing these costly fluids in an environment of storing fire-resistant hydraulic fluids is another issue for mining and construction sites.
Lack of knowledge about the availability of these products. Lack of regulations to require them in specific uses. Higher costs because they tend to be full synthetic polyol esters.
Maintenance understanding by the customers seems to be a large factor. If the decision maker isn’t really familiar with the products and treats them like general lubricants, it can quickly become a maintenance issue that leaves a bad experience for everyone on the peripheral of the decision. Glycols, if not flushed and maintained, can be major issues when not handled correctly; however they can be very good if the team using them knows how to maintain them. Polyols are easy to use but lose their resistance over time, which leads to more frequent changes and higher costs of maintenance, plus reaction of system contaminants accelerates their degradation faster than traditional products and needs to be really understood for long-term success. Phosphate esters can be challenges for cost, handling and environmental but have their places (nonplants). Education with real experiences could help to improve the use of the fluids with the appropriate approach, not watering down of the differences and nuances of these types of products in the application.
Obviously cost. However, it could be used more often in a steel mill making it safer and consolidating fluids. The problem is leaks and not being able to shut down to fix them. Even if you could shut down, there are not enough maintenance people to do the work within a reasonable window. Also there is an environmental concern with the glycol waste in water treatment. Oil is easier to skim and/or contain.
For some use cases (civilian construction or, say, warehouse lifts) the potential for safety improvements don’t yet outweigh the costs. For, say, FAA and Department of Defense, the historical fluids didn’t have the lifetime and/or didn’t provide enough safety improvement to justify costs.
Recent improvements have not been fully communicated to the community or procurement agencies.
To my mind, the most probable would be a combination of ignorance of available product, performance characteristics of fire-resistant fluids not mapping sufficiently to requirements and ease of transitioning from one fluid type to another.
Cost (or perception of higher cost) versus mineral fluids.
Poor performance of water glycol, high cost and few suppliers.
High initial purchase price, incompatible hose material and seals on existing equipment’s hydraulics and proper filtration of fire-resistant fluid on mobile equipment hydraulics.
Not knowing their properties, their toxicity to humans and the environment, as well as the cost of use and methods of possible recycling.
Seal compatibility is usually the biggest obstacle, then cost. Environmental impact may be an issue.
What is the best way to justify the difference in cost between conventional mineral hydraulic oils and fire-resistant oils?
The lifespan
37%
Less leakage
2%
Safety
95%
Better wear performance
27%
Better heat transfer/cooler systems
32%
It’s not a big difference compared with the benefits
2%
Based on an informal poll sent to 15,000 TLT readers. Total exceeds 100% because respondents were allowed to choose more than one answer.
The cost of polyol ester-based fire-resistant hydraulic fluids is prohibitive. Water glycol-based fire-resistant hydraulic fluids are somewhat unstable to manage in the field, and the water content of the fluid leads to early pump failure.
Expense and health-related safety limit the use of it.
The water-based hydraulic fluids do not typically perform as well as hydrocarbon fluids in terms of wear, rusting and rolling contact fatigue. Phosphate ester fluids have other issues that need special care.
Higher cost relative to conventional oils.
1.) Higher cost. 2.) Fluid maintenance is not as simple as mineral oils. 3.) Always some de-rating, especially in the hydraulic system component life, especially since these fluids have lower antiwear. So these fluids are generally used where safety regulations do not permit use of mineral oils.
From my experience, the primary reasons seem to be costs, availability and overall knowledge of the products.
Reasons impeding use: additional work in preparation for use and daily maintenance compared to conventional fluids. Also they are greatly cost disadvantaged versus convention fluids.
The main possible reasons could be the inertia associated with the change to the new concept of fire-resistant fluids along with the higher cost of the fire-resistant fluids compared to regular fluids’ lower cost, higher customer confidence in the regular fluids except for the issue of fire resistance, concerns about the technical performance of the fire-resistant fluids, their higher cost, etc.
Lack of simple information on a comparative basis.
Cost is very prohibitive comparing benefit considering low likelihood of fire accident.
In most cases, the reason is the price. Additionally, it is not clear how long the products can be used according to regulations (e.g., restrictions or bans of chemicals used as anti-flammable agents).
Cost. No legislative imperative for the change. The perception that the mandatory onboard fire suppression equipment is sufficient to deal with the blaze. A perception that it is expensive to use.
Full synthetic can be costly, especially with leaking machinery, which happens a lot in mining applications. Unnecessary if maintenance is up to scratch, then leakage can be greatly reduced. These fluids, in case of diesters, also are readily biodegradable. The water glycol products need a reset of pumps (flow and pressure) due to the nature. Tight control of glycol/water mixture is needed.
Lack of knowledge. Price.
The OEMs do not recommend using fire-resistant fluids. The legislation does not help. Fire-resistant fluids are more expensive. It is easier to formulate a non-fire-resistant fluid. For this reason, not all lubrication producers have them in their range of products and cannot recommend them.
Q.2 Please describe other advantages to using fire-resistant hydraulic fluids instead of conventional mineral hydraulic oils.
Sustainability, better lubricity.
Safety issues in critical applications.
They can be biodegradable and non-toxic if chosen carefully. They can be water-based, thus allowing better heat extraction from the system.
They can last a very long time.
In the case of our polyalkylene glycol technology, it far outperforms other non-fire-resistant synthetics and provides years of use. When using water-based chemistry, there are things that can provide longer life if and only if testing is conducted on a regular basis.
Fire-resistant hydraulic fluids with better protection, but the main thing is safety.
Depending on the technology type, certain FM approved fire-resistant hydraulic oils exhibit superior life expectancy, lubricity and wear performance, extending the life of equipment.
Long life, better maintenance and condition monitoring given the higher cost of the fluid safer and often eco-friendly advantages.
Depending on the types: environmental benefits, temperature range/hydraulic efficiency benefits.
Obviously safer. Possibly deeper insurance discounts. Better heat transfer qualities keeping high pressure applications/equipment cooler.
In a catastrophic failure of a hydraulic line, the particles formed are larger, which means the spread of the spill will be smaller, and there will be less aerosolized mixture that could be inhaled by any workers in the vicinity. The same mechanism seems to improve lifespan/capability by resisting shear elongation of the fluid.
My knowledge of fire-resistant fluids is limited, but to my understanding, the performance characteristics appear to be broadly comparable to typical mineral hydraulic oils with no standout superiorities beyond their fire-resistant character.
Depending on the chemistry, oxidation resistance could be infinitely better than mineral hydraulic fluids.
Water glycol also can be readily biodegradable.
Oxidation resistance, longevity-extended oil life/drain.
The higher stability of features in varying temperature ranges.
Which statement best describes “fire-resistant?”
The ability to suppress a flame
33%
“Fire retardant”
30%
Non-flammable
33%
An FM global-approved fluid
48%
Based on an informal poll sent to 15,000 TLT readers. Total exceeds 100% because respondents were allowed to choose more than one answer.
In ships requiring special classification (like ABS), they impose restrictions on many of the hydraulic components and their use/location in machinery spaces. The use of a fire-resistant fluid would remove many costly additions (like special sight glasses for fluid level in tanks).
Polyol esters are superior base stocks from which to blend lubricants. Great performance. Their cost makes them less attractive.
Certainly fire resistance is the big one.
Oxidation/hydraulic stability and resistivity also are good properties.
Safer to use on things like warships where the risk of fire is significant.
It’s not only for places with risk of fire, but the technology offers better advantages in terms of wear protection, lifespan, etc.
Easier maintenance owing to more well-defined breakdown pathways in synthetic fire-resistant fluids.
Compliance to safety regulatory requirements. Water-based fire-resistant hydraulic fluids may have better cooling characteristics as compared to mineral oils.
Possible consolidation of lubricants between equipment.
Safety.
Along with fire-resistance advantage, it has the following benefits of better resistance to thermo-oxidation and also environmental friendliness.
Longevity.
Long life. Better performance.
Additional time to get out of the area before the oil ignites. Once the ignition source is removed, the fire is easy to get back under control. Depending on the type of fire-resistant hydraulic fluid, you may not get better wear protection or reduced leaking.
Are more eco-friendly (esters-based, water-based).
Some are biodegradable.