WE Have ISOVG32 Hydraulic oil and Turbine oil is our stock. The physical properties of both the oils are more or less same, except the Hydraulic oil contains the ant-wear additive ZDDP. These oils are used for pumps with wet sump lubrication.Now I would like to choose only one type of oil from the above, for all the pumps. Which one I should select - Hydraulic or turbine oil ?

Joy : We have many pumps in our process mostly worthington , we use hydraulic oil esso nuto h 150 with very good results ,May I added that a few years back we consolidated our lubricants in the mill and eliminated our 32 and 68 grades for a 46 grade and felt that it may be to light for some of the more servere service pumps to avoid confussion on topups oil changes etc and on reccommendation from worthington we went this route we also have had the same success with our canada pumps and goulds

My concern is the effect of the Anti-wear additive.For these small pumps does the ZDDP have any adverse effect?

Is there a reason why your company is using two oils in the first place? May be that there are two different pump designs in use? Main adverse effect of ZDDP is that it will corrode copper surfaces. Railroad engines use silver coated bearings and if ZDDP containing oil gets in the engine silver corrosion starts immediately. Other problem with ZDDP is that it becomes corrosive at high temperatures (doubt if it is a concern to you) so that when ground crew top off aircraft engine oil with car oil, the ZDDP undergoes thermal decomposition and resulting strong acids attack metal surfaces. On the other hand we had some hydraulic pumps running a ZDDP containing hydraulic oil (DTE25 I believe) and when the ZDDP was depleted, the pumps failed eventhough the oil was still good (phenolic antioxidant > 80%). So there may be a reason that two oils are used: turbine oil used where ZDDP would cause corrosive attack of copper components and hydraulic fluid used were antiwear capability of ZDDP is needed.

Thanks Bob for the information.Many of these pumps have Anti-friction bearings with brass cage and Inpro seals.Does the ZDDP has affinity to corrode these brass materials too?
The oil type is established based on the different pump manufacturer recommendation.

ZDDP will corrode brass, may actually go after the zinc first (zinc provides cathodic protection to copper in less agressive environments) then copper. Are the pumps with the Anti-friction bearings the ones using the turbine oil?

Thanks for the reply. Is there is any way to confirm and monitor this Corrosion by the ZDDP.We have pumps with antifriction bearing using Turbine as well as Hydraulic oil and not noticed any oil discolouration due to the above phenomena - may be because of low operating temperatures.

Do you perform oil condition monitoring on samples?
Running spectrometric oil analysis, looking for increase in Zn (hard if Zn from spent ZDDP is being removed by in-line filters which negates increases due to Zn wear) or Cu. If Zn or Cu wear is occuring, whether corrosive or abrasive, would expect filtration would isolate particles from obtained oil sample - could use patch test/fine filter to isolate particles to be looked at under magnification. Make sure sample is obtained upstream of in-line filters. Also if you ever change line filters - cut one open and look for copper/brass debris

As I mentioned in the first posting, these are small pumps with wet sump libricaton - with capacity 2 -3 literes.Some of these pumps are having Oil rings, also for lubrication, made of brass.