CONVERTING TO WATER-GLYCOL IS EASY!
Regardless of the type of hydraulic fluid being used, converting a system to water-glycols is easy. Virtually every type of equipment that uses fire resistant hydraulic
fluid has been converted to water-glycols.
If changing seals is necessary, equipment manufacturers can recommend what seals to change, and many carry a supply of correct seals.
Change over Procedure
1. Drain the system as completely as possible paying particular attention to pipe
lines, cylinders, accumulators, dead legs and other requirements where residual oil might be trapped. Clean the inside of the reservoir thoroughly by either steam
cleaning or wiping with lint-free cloth.
2. Remove filters, clean and replace with suitable elements Oiltech water-glycols can be used with all conventional oil seal materials except
polyurethane and those that absorb water. Cork and leather should therefore be avoided.
3. Remove any internal paint unless resistant to water-glycol softening action Water-glycol fluids are not compatible with conventional paints. The inside surfaces
of the system should be stripped of paint before installing water-glycol fluid. Oiltech
water-glycols contain adequate liquid and vapour phase corrosion inhibitors such that
no internal painting is required. If painting is desired however, epoxy resin or phenolic
resin paints may be used.
4. Check seals, hoses, accumulator bladder, pipe-jointing compounds, etc. for compatibility with water-glycol and replace by recommended materials where
necessary.
5. Fill the system with enough Oiltech water-glycol to maintain pump suction and
operate the system at minimum pressure for thirty minutes.
6. Drain the system as completely as possible while the fluid is still warm and without allowing it to settle. This fluid can be retained for further use after any
polyol ester contaminant has been skimmed off and suspended solids have settled.
7. Re-check filters and strainers for contamination.
8. Fill the reservoir with Oiltech water-glycol and clean the reservoir breather and
check the circuit for leakage. The system is now ready for normal operation.
9. During the first few weeks of operation check filters and strainers for deposits
loosened by the detergent action of Oiltech water-glycols.
10. In service monitoring is important with water glycol fluids.
Non-sealing systems operating at elevated temperatures may lose water and vapour phase inhibitor by evaporation. We recommend that systems be initially
monitored for fluid viscosity on a monthly basis, for two to four months, to trend
possible water loss, as indicated by viscosity increase.
System which do not lose water at a rate in excess of 1% per month, can subsequently be monitored approximately six monthly, whereas systems which
lose water at a greater rate should be monitored more regularly for both water content and reserve alkalinity.
Oiltech Australia provides Techcheck Condition Monitoring services which many users found useful as an adjunct to their predictive maintenance system. Be sure
to contact us for more information.