Compressor end of life criteria
Compressor end of life criteria
(OP)
Hi guys,
I am a young engineer with no particular experience in compressed air systems. We have about 300 5-stage air compressors compressing air at 3600 psig with a flow rate of about 29 cfm.
My employer has asked me to develop end of life criteria for these compressors. These end of life criteria would define when the compressors need to be replaced according to different parameters. My employer wants to minimize cost of maintenance and of replacement of compressors while keeping risk low. However, I find it hard to quantify risk...
I will contact the manufacturer but am afraid the criteria they give me will be very conservative..
How do you quantify or decide when a compressor is to be replaced?
Thank you for your help!
I am a young engineer with no particular experience in compressed air systems. We have about 300 5-stage air compressors compressing air at 3600 psig with a flow rate of about 29 cfm.
My employer has asked me to develop end of life criteria for these compressors. These end of life criteria would define when the compressors need to be replaced according to different parameters. My employer wants to minimize cost of maintenance and of replacement of compressors while keeping risk low. However, I find it hard to quantify risk...
I will contact the manufacturer but am afraid the criteria they give me will be very conservative..
How do you quantify or decide when a compressor is to be replaced?
Thank you for your help!





RE: Compressor end of life criteria
You could look at when a combination of maintenance and energy costs (use a surrogate cost to mask price hikes) reach a threashold you toss it. Or you could set a downtime threshold (or a number of outages).
David
RE: Compressor end of life criteria
From "BigInch's Extremely simple theory of everything."
RE: Compressor end of life criteria
When you calculate your Present Value with all the maintenance costs of the worn compressor, what time period do you consider?
Do you consider the foreseen compressor life as a present value for the maintenance costs?
Thanks!
RE: Compressor end of life criteria
For example
Worn compressor requires a rebuild today: $ 10,000
and maintenance costs of 5,000 this year
7,000 next year,
9,000 in year 3
12,000 in year 4
20,000 in year 5
25,000 in year 6
35,000 in year 7
Take the PV of each of those maintenance expenses, plus the power cost too, if that's going to vary between alternatives, plus adding a new unit at the end of each of those years and the new unit's costs until it's life ends, or the time that the sequence reaches the end of the lifetime of a new unit added now today.
Compare the PV of a new unit with all of the alternatives of allowing the old one to continue with replacement option at the end of each of those years. Then if there are any cases with similar numbers, that would be the maximum time to replace.
From "BigInch's Extremely simple theory of everything."