Q & A > Question Details
For any industrial compressor why do we assign the interlock like this:
Low pressure trip for lube oil and low flow trip for cooling water
and why not vice versa ?
09/04/2010 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Actually, flow measurement is more reliable for either, because unexpected backpressure could reduce the flow undetected and cause trouble. Temperature is another good way to spot trouble, isn't it?
09/04/2010 A: keith bowers, B and B Consulting, kebowers47@gmail.com
Lube oil pressure in the bearing supply gallery is the best indicator of bearing health in most cases. Loss of pressure is a critical event requiring immediate shut-down to avoid catastrophic destruction
Cooling water systems usually have very 'flat' pressure to flow rate curves (by design). This means a significant decrease in CW flow rate (what the machine needs) may not be accompanied with a pressure change and the change could be either positive or negative depending on the cause. Flow rate is the important factor, not pressure.