FAQs

This is one of the most common calls we get, and it is almost always contamination, not a product defect. The usual suspects:

• · Residual refrigeration oil or ammonia left in the system from a previous fluid
• · Poor makeup-water quality — high mineral content or biological contamination
• · System not cleaned before filling — old inhibitors and sludge from the previous fluid react with the new charge

Send us a sample for lab analysis. In mild cases, the fluid can be reconditioned with a performance-enhancer additive. In severe cases, you need to drain the system, clean it thoroughly, and refill. If you skip the cleaning step, the new charge will fail the same way.

Check the system pH first. An abnormal pH is the most common trigger for copper corrosion. Standard LM-4 uses nitrite-based inhibitors, which can be aggressive toward copper under certain pH conditions.

If copper corrosion is significant, switch to LM-4D. It is nitrite-free and formulated to be copper-friendly. We recommend pulling a fluid sample before and after the change to measure the actual corrosion rate.

Product: LM-4D (nitrite-free, copper-friendly, low conductivity)

It depends on how much and how long. For HCl ingress: HCl dissolves readily in water-based coolants without violent reaction. But it destroys the corrosion-inhibitor package. Add our performance enhancer plus alkali to bring the pH back into the normal range (7.5 to 9.5 for most products), then monitor continuously.

For ammonia ingress: organic acids can bring the pH down, but this treats the symptom, not the cause. As long as ammonia keeps entering the system, corrosion continues. The only lasting solution is to fix the ammonia leak and replace the fluid.

In severe cases, the only reliable fix is a complete fluid replacement after thorough system cleaning.

Not necessarily. We have investigated this exact situation. The fluid itself tested non-corrosive to aluminum in our lab. When we cut open a perforated tube section, we found crystalline deposits on the pipe wall causing localized crevice corrosion — an electrochemical attack driven by the deposit, not the fluid chemistry.

Our diagnostic approach: sample the fluid and measure its corrosion rate against aluminum. Then cut out a perforated section for microscopic analysis. The result determines whether we adjust the formulation, recommend LM-4L or LM-4ABL, or whether the root cause is something else entirely — like poor water treatment leaving mineral deposits.

Products: LM-4L, LM-4ABL (aluminum-optimized formulations)

LM-11D is a water-free coolant, and any water that enters will freeze at low temperature, blocking pipes and locking the pump. Recovery procedure:

• · Physical separation: drain the fluid and let it stand. Water is denser than LM-11D and will settle to the bottom. Take the upper layer back into service.
• · Molecular-sieve drying: treat the residual moisture with molecular sieves (3A or 4A type). Circulate the fluid through the sieve bed until water content is acceptable.
• · Filter: install a filter before the pump inlet and clean it regularly based on pump running current.
• · Prevent recurrence: keep the expansion tank sealed under a dry-nitrogen blanket. Never use water for pressure testing.

We have seen systems recover to 47 ppm water content after this treatment. Systems with 104 ppm water struggled to reach -40 C. After treatment, verify water content analytically.

Work through these causes in order:

1. Pump flow rate — is the pump actually delivering design flow? Undersized pumps are the number one cause.

2. Local ice on the evaporator or plate heat exchanger — warm the system above 0 C to melt it, then reset the target and cool down slowly.

3. Concentration too high — over-concentrated fluid is more viscous and reduces flow. Reducing concentration slightly often restores circulation.

4. Thermal conductivity difference — if you replaced an older fluid, compare thermal conductivity and specific heat, not just the freezing point.

We have seen LM-8 systems stall at -42 C (setpoint -50 C) because the plate heat exchanger was icing locally. The fix: raise the evaporation temperature, let the ice melt, then step the temperature down slowly.

Usually it is a property difference, not a defect. Compare the old and new fluid's thermal conductivity and viscosity:

• · A fluid with lower thermal conductivity carries less heat per unit of heat-exchange area. This is the most common reason for a performance drop.
• · Viscosity affects flow but rarely explains a big performance drop. As a rule of thumb: a 7.5% viscosity increase means roughly 7.5% more flow resistance, but only about 1.5% heat-transfer penalty.

We have seen this with LM-11F replacing another product. We can run the calculation for your specific fluids before you change anything.

Some enhancer components can precipitate as foam when conditions shift — temperature, pH, or concentration. The foam layer sits on top of the fluid and insulates it, reducing heat exchange at the tank surface and sometimes pulling air into the pump.

Recovery steps:

• · Skim the foam off the tank surface. Do not let it recirculate.
• · If foaming persists, dose a compatible defoamer. Contact us for the right type.
• · Stop refrigeration and circulate the fluid for 24 hours. This lets remaining additive components fully dissolve and trapped gas escape.
• · Resume cooling and observe. If the problem recurs, we may need to adjust the additive type or dosage.

We have seen this in an LM-4 system where the enhancer was added too quickly. The 24-hour circulation resolved it.

This is thermal expansion with nowhere to go. As the fluid warms or cools through a shutdown, its volume changes. Without a relief path, pressure spikes. We have seen an LM-8 system go from 3 bar to 8 bar after shutdown for exactly this reason.

The fix: install an expansion tank or a pressurization/make-up unit sized for your fluid volume and temperature swing. This is a design requirement, not a fluid issue.

If you are seeing this at the high point of the system, the issue is flashing — the local pressure has fallen to the fluid's saturated vapor pressure. Raise the system pressure (for example, increase the nitrogen blanket from 50 kPa to 80 kPa).

Closing both the inlet and outlet valves traps a fixed volume of fluid. Any temperature change then generates enormous pressure — liquids are nearly incompressible. The pressure can permanently deform the reactor vessel.

This has happened with LM-11C, where the outlet valve was closed and the trapped fluid expanded with a temperature rise. Prevention:

• · Never fully close the outlet valve on a water-free coolant loop. Keep the reactor connected to the expansion tank.
• · If the process requires isolating the reactor, install a dedicated safety-relief device on the trapped section.
• · For LM-11C specifically: the outlet valve must remain open.

No — this is water contamination. LM-15B is a heat transfer oil rated to 200 C, but it cannot tolerate water. If water is present, it boils at 100 C, creating steam that carries hot oil out of the vessel.

Before heating LM-15B or any heat transfer oil:

• · Let the fluid stand so free water separates and settles to the bottom. Drain it.
• · Verify the total water content is within specification.
• · Only then raise the temperature. Heat slowly through the 100 C range to let any residual moisture evaporate gently.

LM-11D has lower specific heat and lower thermal conductivity than LM-4. It is a water-free modified alkane, while LM-4 is a water-based diol fluid. Water-based fluids generally have better heat-transfer properties than water-free fluids.

When you switch from LM-4 to LM-11D, the heat-transfer capacity of the fluid drops. Your heat exchanger and pump were sized for LM-4's properties. LM-11D simply cannot carry as much heat per unit volume.

This is not a defect — it is a property difference. If you need water-free operation at low temperatures, LM-11D is the right product. But you may need to increase the heat-exchange area or flow rate to compensate. We can run the calculation for your system before you make the switch.

Water-free (LM-11D) and water-based (LM-8) fluids have very different physical properties. The hydraulic and thermal design must be re-verified:

• · Piping: may need upsizing. Depending on the original design, plan for DN40 or DN50 instead of smaller lines.
• · Flow: LM-11D needs roughly double the volumetric flow of LM-8 for the same heat duty. Check your pump capacity.
• · Heat-exchange area: plan for about 1.5 times more area to compensate for LM-11D's lower thermal conductivity.

Send us your system parameters — pipe sizes, pump curve, heat exchanger specs, and operating temperatures — and we will run the full heat-transfer and pump-capacity calculation before you commit. This is a free service.

In most cases, yes — and it removes a serious safety problem. Methanol has a flash point around 30 C, which makes it a fire hazard. LM-4 does not flash at 93 C and is non-flammable.

We compare viscosity and other parameters between LM-4 and your current methanol concentration, then check them against the installed pump curve. The feasibility is usually high. We have done this for heat-source tower applications where methanol-glycol mixtures were replaced with LM-8, eliminating the fire risk while maintaining heating performance.

Products: LM-4 (non-flammable, -20 to 150 C), LM-8 (non-flammable, -50 to 120 C)

Two fluid-side factors dominate cold-storage temperature problems:

• · Concentration: over-concentration raises viscosity and chokes flow. Reducing the concentration slightly often restores circulation and cooling. We have seen LM-445 systems where the concentration was too high and the temperature would not go below -16 C.
• · System configuration: add an electric (motorized) valve on the return line to prevent backflow, and add air vents at the ends of branch lines to eliminate trapped gas. Trapped air in the piping reduces effective heat-exchange area.

If both check out, verify the refrigeration plant capacity and pump sizing. Send us the P and ID and operating data. We will review it at no charge.