Product Substitution & Performance Comparison
Coolant replacement is not simply changing fluids - physical property difference calculation, pipe modification, and heat exchange capacity evaluation. 4 typical replacement cases analyzed in depth.
4 Replacement Scenarios
5-Step Evaluation Process
5 Risk Reminders
Product Substitution & Performance Comparison
Coolant replacement is not simply changing fluids - physical property difference calculation, pipe modification, and heat exchange capacity evaluation. 4 typical replacement cases analyzed in depth.
Replacement Is Not Simply "Changing Fluids"
Coolant replacement is one of the most carefully handled scenarios in technical support. Different coolant models may have significant differences in key physical properties such as viscosity, thermal conductivity, and specific heat. Direct replacement can lead to insufficient flow, reduced heat exchange capacity, pipe incompatibility, and other issues.
Every successful replacement requires physical property parameter comparison calculations to evaluate the impact on pump delivery, heat exchange, and system piping, with system modifications when necessary.
TypicalReplacement Scenarios
LM-11D Replacing LM-8
Motivation: Customer wants water-free type to replace water-based, avoiding low-temperature icing risk. Property differences: LM-11D viscosity and specific heat differ significantly from LM-8. Modification requirements: Pipes enlarged from DN32 to DN40/DN50, flow rate doubled, heat exchange area increased 1.5x. Assessment: High modification cost, comprehensive evaluation needed.
LM-4 Replacing Methanol Solution
Motivation: Methanol has low flash point and safety hazards. Property differences: Compare LM-4 vs methanol viscosity and other parameters. Modification requirements: Assess feasibility based on on-site pump operating conditions. Assessment: Usually highly feasible - LM-4 offers better safety and cost-effectiveness than methanol.
Finding Alternatives for High-Priced Products
Motivation: Customer feels the originally recommended product is too expensive. Method: Understand core requirements (temperature, materials, key indicators) and recommend a more cost-effective alternative. Assessment: If no alternative is available, explain the reasons rather than force an unsuitable substitution.
LM-11D Replacing LM-4
Motivation: Pursuing lower temperatures or water-free conditions. Property differences: LM-11D specific heat and thermal conductivity both lower than LM-4. Result: Poor heat exchange caused temperature to not cool down. Customer considered switching back to LM-4. Lesson: Always compare thermal conductivity and specific heat before replacement.
ReplacementReal Cases
ReplacementEvaluation Process
Define Replacement Motivation
Is it a safety need (e.g., methanol low flash point), performance need (e.g., lower temperature), cost need (e.g., original product too expensive), or environmental need? Different motivations affect the direction of alternative product selection.
Compare Key Physical Properties
Must compare: viscosity (affects flow and resistance), thermal conductivity (affects heat exchange), specific heat (affects cooling capacity), freezing point (affects safety margin), flash point (affects safety). 7.5% viscosity increase = 7.5% resistance impact, 1.5% heat exchange impact.
Assess System Modification Needs
Based on property differences, calculate whether pipe enlargement, pump replacement (larger flow), or increased heat exchange area is needed. LM-11D replacing LM-8 requires pipes from DN32 to DN40/DN50, flow doubled, heat exchange area increased 1.5x.
Calculate Modification Cost vs Benefit
Comprehensively evaluate modification cost, operating cost changes, and performance improvement after replacement. If modification cost is too high or performance decreases, recommend maintaining the original solution or choosing another alternative.
Develop Replacement Implementation Plan
After confirming replacement, develop a detailed implementation plan: system cleaning and draining, new coolant filling, pipe modification, pump adjustment, and trial operation verification. Implement step by step with gradual verification.
1. Thermal conductivity differences are the most easily overlooked parameter. LM-11F has lower viscosity than LM-1 but half the thermal conductivity, directly causing poor cooling.
2. Specific heat differences affect cooling capacity. LM-11D specific heat is lower than LM-4, reducing cooling at the same flow rate.
3. Pipe compatibility must be assessed in advance. Mismatched pipe diameters cause severely insufficient flow.
4. Water-free requirement changes need special attention. When replacing water-based with water-free, the system must be thoroughly dried.
5. If performance is inadequate after replacement, roll back or adjust the plan promptly to avoid prolonged inefficient operation.
SubstitutionFAQ
Solution: Calculate heat transfer and pump delivery capacity changes: pipes may need enlargement (DN40 or DN50), flow rate needs to double compared to LM-8, heat exchange area needs 1.5x increase
Solution: Compare viscosity and other parameters of LM-4 with methanol solution, assess feasibility based on on-site pump operating status. Generally high feasibility
Solution: Understand customer core needs (temperature, materials, key indicators), recommend more cost-effective alternative models. If no alternative available, explain why
Post time: Aug-27-2026