Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/1222953
Contamination Control AS I SEE IT Jim Fitch | Noria Corporation Control Moisture Ingression with Tactical Inspection 2.0 You don't have to remove what you don't allow to enter. Indeed, it's hard to chal- lenge the logic and value of controlling water ingression, but because moisture is everywhere, achieving bone-dry oil through exclusion alone may not be practical or even necessary. Lubri- cating oils have different degrees of hygroscopicity (water-loving tendencies), making the control of all dissolved water an almost futile exercise. However, for many applications, it's the free and emulsified water that is the most destructive and, hence, the central target for control and inspection. Exclusion relates to the process of preventing (excluding) the ingress of water from environmental, machine and process sources. Common points of water ingression include: 1. Water from make-up oil (some supply tanks can collect inches of undetected bottom water) 2. Turbine gland steam seals (e.g., improper pressure regulation) 3. Defective vapor-extraction system (if too high, it can suck in steam, while if it's too low, it can fail to keep up with ingress) 4. Process water in-leakage from pulp and paper production, water treatment plants, sewage treatment plants, etc. 5. Oil cooler leaks 6. In-leakage of water past seals from washdown sprays, rain and flooding conditions 7. Reser voir a nd su mp head space vent / breather ingress "Inspection is the top-line priority needed to squelch moisture ingression points through tight and well-managed ingression control." 2 | March - April 2020 | www . machinerylubrication.com WATER SOURCES IN STEAM TURBINE LUBRICANTS • Water-contaminated make-up oil — Inspect new oil. Never introduce a cloudy oil into a lube oil reservoir. • Improper operation of vapor-extraction system — Fans causing too low of a vacuum can result in a build-up of humidity. Fans causing too high of a vacuum (plugged panel filter) can pull in more gland steam or cause oil carry-over to the roof. Regularly inspect and service vapor-extraction fan panel filters. • Oil cooler leaks • Excessive leakage from gland steam seals — Inspect the gland inlet and outlet pressure and regulate accordingly. Tank-top vapor-extraction fan and panel filter.