Steel Mill Alarms & Valve Sticking? Multi-Stage Oil Filter Elements + High-Temp Media
May 14, 2023
Steel mill HPUs face hot oil mixed with iron oxide, carbon black, and micron-level debris. Customers see servo/proportional valve sticking, pressure fluctuation, and repeated ΔP alarms even after replacement. Single-stage filtration can’t balance high flow and fine accuracy.
Adopt graded filtration: use 10 μm β≥200 elements in pressure lines to protect valves; use 25 μm β≥75 high dirt-holding return filters to capture coarse particles; add a second 10 μm return fine stage if servo valves exist. This stabilizes cleanliness without excessive ΔP.
Temperature matching is critical. Oil often runs at 70–90°C+, where cellulose media ages quickly. Choose glass fiber or sintered metal media rated 120–200°C. Control oil oxidation (monitor viscosity/TAN) because varnish causes fast surface blinding. Replace when ΔP ≈0.3 MPa with sluggish valve response, and also check coolers, seals, and tank rust flakes.
