frick scew cuts out lo oil press

[marley]

I,m working with a frick screw comp(400H.P) it will run for roughly 5 minutes then it cuts out on lo oil press. some info I read says the oil pressure should be 15 to 20 psi above discharge pressure, what I'm reading on the pressure gauges reads only about 3 to 5 psi diference, my question is would the problem with this machine be the pressure regulator(A4AL valve) or would it be the oil pump(viking AK195) I turned the stem on the pressure valve a few turns with no increase in oil pressure. can some one please give me some pointers, thanks

[NH3LVR]

First in the matter of gauges-trust but verify!
I think Frick likes a little more oil pressure than that (15-20lbs).
Let us assume that your oil is not full of refrigerant and the temperature is normal. We also assume that the Viking does not have a clogged strainer and the bypass on the pump (if it has one) is not stuck open.
We also assume this has a full time oil pump.
I also think that from your description of the problem that the oil pressure must be more than 3-5lbs on startup or it would not run for any time at all. This usually means the oil is getting warm. Maybe just coming up to normal temperature.

The oil pressure regulator can cause low oil pressure if it sticks open. You can valve it off while watching the pressure on a gauge. BE CAREFUL! If the regulator is open your oil pressure will raise very quickly as you close the valve if this is the case.

Having eliminated the regulator I would suspect the pump. Especially if it quits working as the oil temperature rises.
Be aware that there is very little difference between a pump that causes the problem you describe and one that works well. I took a pump off a machine a few years ago that behaved as yours did. I took it to a reputable shop. They called to tell us that the pump was fine. and it was-on their bench. We replaced it and the problems were solved.

[marley]

NH3LVR,
thanks for the info,what would be a correct oil pressure for this machine? the viking pump on this machine does not have a by pass.but I think it has an oil strainer,this screw is an older machine when I go to start it I have to reset an oil failure switch,I have to fool the machine to start by moving the slide valve sensor.

[PaulZ]

Hi Marley
If you have checked everything NH3LVR has said and you still have a problem with oil pressure check the clearance of the Viking pump. If the pump looks ok inside with no damage or wear to the end plates or gears the end clearance could be too large.
I am pretty sure you can adjust the end clearance on that model pump. If on the drive end there is a collar that sits proud of the body there is a small screw that locks it in position. With the pump stopped undo the small screws and screw this collar into the pump while rotating the pump by hand. As soon as you feel slight resistance back it off between 1/8 and 1/4 turns, lock the screws in place and run the pump. This is the case with the HL4195 and AL4195 pumps.
I think I have a manual but would be too big to post here. Send me a PM with your email and I will send you a copy.
Paul

[la461]

If you have an older package with a Mycom or Dunham/Bush the oil pressure is held at the babbitt mains. If the inlet end bearings are worn it allows excessive oil to pass to the suction and as the screw loads, increasing suction flow velocity, causing the oil to be pulled into the gas stream faster than the oil pump can supply the bearings with oil and the oil pressure will be lost causing low oil pressure failure. Happens everytime.

[TXiceman]

Marley, I hate to say it, but sounds like you need to get a Frick technician in to cehck the system. How many hours are on the machine since new or the last rebuild? What is the filter pressure drop?

Ken

[ammonia tec]

Marley, I hate to say it, but sounds like you need to get a Frick technician in to cehck the system. How many hours are on the machine since new or the last rebuild? What is the filter pressure drop?

Ken
what about frick that has no running pump just on start-up.then it cuts off. new oil filter ,coalescer and clean strainners.this comp. always ran on border line of 20 to 25 diff.? im going to keep it pumped out untill i can think of something.

[ammonia tec]

check the back plate sometimes u need to adjust due to worn age or loose. dont forget to back off a little after tightening it.

[ammonia tec]

hes right that how u do most pumps. viking.




uote=PaulZ;159164]Hi Marley
If you have checked everything NH3LVR has said and you still have a problem with oil pressure check the clearance of the Viking pump. If the pump looks ok inside with no damage or wear to the end plates or gears the end clearance could be too large.
I am pretty sure you can adjust the end clearance on that model pump. If on the drive end there is a collar that sits proud of the body there is a small screw that locks it in position. With the pump stopped undo the small screws and screw this collar into the pump while rotating the pump by hand. As soon as you feel slight resistance back it off between 1/8 and 1/4 turns, lock the screws in place and run the pump. This is the case with the HL4195 and AL4195 pumps.
I think I have a manual but would be too big to post here. Send me a PM with your email and I will send you a copy.
Paul[/quote]