oil pressure

[stanthonycold]

Should oil and discharge pressure be close to same?

Compressor #1 sab 163 rotary screw..... discharge 140 psi
oil pressure 125 psi

Compressor #2 discharge and oil pressure are the same which i think is correct .

[Grizzly]

Hi Stan?
I have never really paid much attention to the differential between the discharge pressure and the oil pressure.
The really relevant one is the oil pressure diff.
As measured across the oil filter, usually with a Oil diff max of 1 bar.

Have you checked your transducers lately?
Cheers Grizzly

[stanthonycold]

Hi Stan?
I have never really paid much attention to the differential between the discharge pressure and the oil pressure.
The really relevant one is the oil pressure diff.
As measured across the oil filter, usually with a Oil diff max of 1 bar.

Have you checked your transducers lately?
Cheers Grizzly

Yea i checked the trancducers and re-calibrated to gauge pressure readings.Pressure across the filter is around 3 psi on 1 comp and o.o on the other.Maybe time to change /clean filter?

[Eeram]

On screw compressors, oil pressure should be the same as discharge pressure. If there is a difference of about 15 psi, oil filters should be changed.

[Grizzly]

Yea i checked the trancducers and re-calibrated to gauge pressure readings.Pressure across the filter is around 3 psi on 1 comp and o.o on the other.Maybe time to change /clean filter?

Nah, 3psi is OK.
When it gets near to the 1 bar then it's time to change the filter.
What's your oil temps like on each of the comps?
I am assuming the oil is the same age on each and their run hours are similar?
Cheers Grizzly

[stanthonycold]

Nah, 3psi is OK.
When it gets near to the 1 bar then it's time to change the filter.
What's your oil temps like on each of the comps?
I am assuming the oil is the same age on each and their run hours are similar?
Cheers Grizzly

Yes oil was changed same time

Comp 1
oil pressure-120psi
discharge pressure- 133psi
oil temp _ 58.4 celsius
oil sump 75 celsius
Discharge temp 75-76 celsius


Comp 2

oil pressure and discharge pressure are the same !!

oil temp 55
oil sump 70
discharge temp 70

[Grizzly]

I cannot advise further at the moment as I don't have any plant logs at home.
But if you don't get further advise from on of the other guys.
I will check the details when next on-site.
Has this problem just occurred?
Or has there always been a difference?
Only there is a factory set oil pressure regulator within the Oil circuit.
Just maybe there has always been a difference between the 2?
Cheers Grizzly

[daniel25486]

Hi.

Your compressor dosent have an oilpump, or better the oil pump i sonly for the start sequence - pre-lubrication, your compressor only starts up if it has oil pressure, as the comrpessor starts the pressure on the oil goes near the dicharge. an oil separator is mounted on the dicharge side, so de pressure your mesuring is normal.
whats forces the oil to move in the system after start is the high pressure. Am I correct?

That compressor comes with a 3 way valve in oil pipping for temperature control. Also check that.

[Sandro Baptista]

Hi.
whats forces the oil to move in the system after start is the high pressure. Am I correct?

More precisely is the pressure difference between the discharge pressure and the several points where the oil goes which are at a lower pressure. Only by that it coud have flux of oil.

[getinby]

Have a york dxs45 compressor running very hot along bottom of compressor, even into the suction end. Fla% is 47 at 91A. It is at 75 steps, have 10vdc to cap valve should be fully loaded. Oil level is only into the bottom SG after an hour of runtime. Have six of the same compressor, this is the only one doing this. Any insight on this.

[Sandro Baptista]

Have a york dxs45 compressor running very hot along bottom of compressor, even into the suction end. Fla% is 47 at 91A. It is at 75 steps, have 10vdc to cap valve should be fully loaded. Oil level is only into the bottom SG after an hour of runtime. Have six of the same compressor, this is the only one doing this. Any insight on this.

See if it is entering hot gas to the crankcase instead of oil returned.