Industry Application
EHC Hydraulic Systems
Electro-hydraulic control (EHC) systems on steam turbines use phosphate ester-based fluid that requires chemically compatible filter elements. The HYCOA S Series synthetic element and JR-33 transfer valve are the correct choice for EHC applications.
EHC System Requirements
Phosphate Ester Compatible
EHC fluid is chemically aggressive. The S Series pleated synthetic media is chemically resistant — cellulose elements will degrade and must not be used.
Zero Leakage Transfer
The JR-33 transfer valve ensures the active filter is always fully in service — no bypass to servo valves or actuators during filter switching.
Fine Filtration
EHC servo valves require fine, clean fluid. S Series elements are available in ½ to 20 micron nominal ratings to meet system cleanliness requirements.
No Lubrication Required
The JR-33 transfer valve requires no lubrication — important in EHC applications where contamination of the hydraulic fluid must be avoided.
Recommended Products for EHC Systems
S Series Filter Elements
Pleated synthetic media — phosphate ester compatible, ½–20 micron nominal.
View6-Way Same-Side Transfer Valve
For duplex EHC filter switching — zero leakage, no lubrication required.
View3-Way Transfer Valve
For single-circuit EHC filter switching applications.
ViewFilter Elements Overview
Compare all five element series — C, S, V, 2200, and 2710.
ViewFrequently Asked Questions
Specify the Right EHC Filter Elements
Contact our team with your EHC system specifications and we'll recommend the correct S Series element and micron rating.
HYCOA® JR-33
Select a Valve
- JR3
3-Way Transfer Valve
Single flow path switching
- TP
3-Way Twin-Pak
Inlet + outlet in one body
- 6SS
6-Way Same-Side
Most popular duplex config
- 6IL
6-Way Inline
Straight-through piping
- 6OS
6-Way Opposite Side
Opposing supply & return lines
- HIC
HICORP Transfer Valves
2″ – 12″ large-bore service
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