Fluid Care Education
Fluid maintenance is as important as maintaining mechanical parts. If your system is not running as it should, it may be time to perform maintenance on your thermal fluid. HEAT can help you diagnose and correct these problems, even helping to avoid downtime.
Read on to learn more about some symptoms of degraded or contaminated thermal fluid and how to take corrective action and keep your process running safely.

Symptoms of Fluid Degradation or Contamination
These symptoms are common indications that maintenance must be performed. The sooner the problem is diagnosed, the less risk there is of system downtime.
- Batch times longer
- Heat-up or cool-down times longer
- Pressure drops higher
- Temperature at process exchanger has changed
- Pump cavitation
- Overflow from expansion tank
- Relief from PSVs
- Gurgling sounds
- Fluid color has changed
- Fluid odor has changed
- Pipe & valve corrosion
- Fluid leaks
- Seal failures
- Vessel jackets plugged
- Instrument lines plugged
- Unable to start up at low temperatures
- Over temperature alarms
- New vibrations
- Lower flow rates
- Sludge from drains
- Unable to remove heater bundles
- Fouling/plugging of pipe
Possible Reasons
Usually, these symptoms are a result of either Fluid Degradation or Fluid Contamination.
Fluid Degradation
—evidenced by changes in composition & changes to physical properties:
- Change in Density
- Change in Viscosity
- Change in Heat Capacity
- Change in Thermal Conductivity
- Increased Insoluble Solids
- Increased Acidity
- Decrease in Flash Point
- Decrease in Fire Point
- Increase in Vapor Pressure
- Decrease in Boiling Point
Fluid Contamination
- Water in the Fluid
- Improper Make-Up Fluid Added
- Process leaking into Fluid
- Foreign Materials in Fluid:
- Rust
- Weld Slag
- Machining Oils
- Chemicals
Possible Root Cause
Once the reason is diagnosed, the root cause must be found and addressed, otherwise the issue(s) will continue.
Thermal Stress Degradation
- From High Temperature Excursions
- From Low Flow vs. High Heater Flux
Age Related Degradation from Lack of Fluid Stewardship
- No Fluid Changes
- No Filtration
- No Venting System
- Excessive Venting
- No Make-Up System
- Moisture Intrusions
Oxidation Degradation
- Hot Expansion Tank Open to Atmosphere
- Malfunctioning Inert Gas Blanketing on Tank
Event Related Causes
- Mixing Different Brands & Types of Fluid
- Equipment Failure Leaking Process into Thermal Fluid
- Recent Piping Changes
- Recent Addition of New Process Equipment
- System Modifications
- Adding Vented Fluids Back into System
Corrective Actions
After the root cause has been identified and addressed, corrective action can be taken to rehabilitate or replace the fluid or decontaminate the entire system as necessary. HEAT has developed a variety of specialized products and services for fluid care or rehabilitation. Each solution is developed individually for each customer.
Level #1 - Rehabilitation of Existing Fluid
- Low Temp Filtration
- High Temp Filtration
- Vacuum Dehydration
- Partial Fluid Changes
- Light Ends Venting
Level #2 - Fluid Replacement
- Evacuation of All Fluid
- New Charge of Virgin Fluid
- Virgin Fluid will Dissolve and Entrain Residual Debris from Pipe Internals
- Remove Residual Debris with Polishing Filtration
Level #3 - Decontamination of Entire System & Piping
- Hot Fluid Removal
- Physical Inspections
- Charge with Flushing Fluid or Sacrificial Fluid
- High Velocity Hot Flushing and Filtration of System
Drain Flushing Fluid and Refill with Virgin Fluid - Remove Residual Debris with Polish Filtration
Preventative Care
Routine fluid care can greatly reduce maintenance costs over time and keep your system operating safely and running like new.
If you are not implementing preventative care practices, here are HEAT’s recommendations for making changes to your process and procedures to maintain proper fluid stewardship:
Modifications to System:
- Add Fluid Sampling Device
- Add Inert Gas Blanketing
- Add Filtration System
- Add Flash Point Management
- Replace Defective Equipment
- Upgrade Safety Controls & Interlocks
Modifications to Procedures for Proper Fluid Stewardship:
- Fluid Testing Program
- Data Tracking of Fluid Condition for Changes
- Partial Fluid Replacement Schedule
- Light Ends Removal Schedule
- Fluid Filtration Schedule to Remove Solids
- Training on Fluid Care

Contact Customer Service
Phone: 412-276-3388
Fax: 412-276-3397