Oil Circulating & Jacking Systems

Oil circulating and jacking systems are not only used to pump oil to bearings or gears to lubricate them but also to purge them of wear debris and, if necessary, to remove heat introduced into the oil by power losses due to friction.

Prolube have a multipurpose range of oil systems as shown. However, the majority of oil systems are nearly always custom designed to suit the application. Combination oil circulating and jacking systems are manufactured for hydrodynamic/static applications.

Reservoirs, pumps, filters, oil coolers, reservoir heating, pressure control and instrumentation are selected depending on the duty and the viscosity of the lubricant required to be pumped. 


These can be fitted in our works on top of the oil reservoir or on a separate skid to form a compact unit but also, for larger systems, as individual items of equipment which are mounted on site and piped up to the plant being served.

  • Prolube has many years experience in the design of oil circulating & jacking systems having supplied systems with flows from less than 5 liters per minute to over 1000 liters per minute and pressures up to 300 Bar
  • Only high quality proven components are used, as the system normally has to operate continuously 24 hours per day throughout the year.
  • The system is continuously monitored allowing attendant free operation.
  • Prolube’s design department produces high quality drawings using AutoCAD. These can be e-mailed, reducing the communication times for drawing approval between design departments.
  • Using a Prolube designed oil circulating and jacking system extends the life of the bearings or gears, reduces the number of plant shutdowns for maintenance and increases the time between oil changes.

Re-circulating oil systems


Technical data

The Prolube oil circulating & jacking system will include a selection of the following equipment:


Most oil system reservoirs are of rectangular construction often forming the base onto which other items are mounted. The size of the reservoir depends on several factors. If the returning oil is likely to contain water or dirt contamination or entrapped air, the reservoir needs to have up to 40 minutes dwell period to allow time for these to separate from the oil. However, if the system is relatively clean, the dwell time could be less than 10 minutes. Another factor would be the need to dissipate heat. Having a larger reservoir could avoid having to fit an oil cooler and its associated control equipment.

Reservoir heating

Unless low viscosity oil is being used, it is likely that some form of heating is required in the reservoir. The main reason for this is that most flow control devices in a lubrication system are simple needle valves or orifice plates and for a correct balance of the system, it is necessary to deliver oil at a constant viscosity. It is easier to control this at a temperature slightly higher than ambient. Other reasons for fitting heating are to be able to start pumping under cold start-up conditions and to assist air release from the returning oil. This heating would normally be electric but steam heating can be fitted. Either method will require thermostatic and level control.


This is only required when heat is introduced into the oil from the process due to friction power losses etc. and this cannot be removed by natural convection hence raising the oil temperature above its desired control level. Oil/water coolers (shell and tube or plate) or air blast coolers are used.


All the above operations require a full range of pressure, temperature and flow valves and instrumentation to operate the lubrication system at its design constant pressure and flow parameters. These are selected to control and monitor the system providing interlocks with the plant so that, providing routine maintenance such as filter cleaning or oil changes are carried out, the lubrication system can operate totally automatic as a servant to plant


Positive displacement pumps (gear and screw) are generally used although centrifugal pumps are used on some viscosity applications (such as turbine oil systems) and piston pumps on high-pressure applications (jacking systems.) Normally two pumps (main and standby) are fitted to give automatic changeover to continue the operation should a fault occur. Pumps are usually driven by an electric motor but on some systems, the main pump is driven directly by the plant being served.


The type filter fitted depends on the acceptable degree of filtration of the equipment being served. If considerable contamination is expected and the bearings are reasonably tolerant, duplex re-cleanable filters are used. The lowest limit of filtration of this type of filter is 25 micron. If the oil returning is relatively clean, disposable element filters with much lower filtration levels are used, considerably extending the life of the oil and the bearings etc.



Modern manufacturing processes in industry present ever increasing load and speed demands on the plant being used. There is, therefore, an ever-growing necessity for efficient lubrication and oil purification requiring oil circulating systems of both special and standard design. With more than 20 years experience of the widely varied needs of industry, Prolube Marketing has supplied systems to serve the equipment of the major industries, and they are proud to have played a part in some of the outstanding engineering achievements during this time. The following are some examples of the types of applications with which we have been successfully involved.


Main roll bearings of rubber mills and calenders require a special flood lubrication system which generally has an oil flow of 50 to 100 liters/min. The complete automatic Prolube system includes motor driven pumping unit, supply reservoir, cooler, filter and flow indicators. The unit also has a special safety feature which prevents calender operation, should the oil pressure fall below a set level.


The Prolube system for the lubrication of paper machines delivers oil at pressure from the lubrication unit through supply mains running along both sides of the paper machine and is directed to the bearings through metering valves. The gear feeds are taken from parallel mains operating at reduced pressure and regulated at each point by control valves. The return oil gravitates back to the reservoir.
Thermostatically controlled heaters maintain the oil temperature ready for immediate start; a pressure control valve automatically adjust the output to suit system demands; appropriate filtering arrangements are incorporated and comprehensive alarm system may be built in to give warning of failure and indicate the location of any fault


The Morgoil bearing is a combined radial and thrust bearing capable of withstanding the high loading characteristics normally associated with rolling mill back-up rolls. A high viscosity index oil is necessary for lubrication and must possess good water separating properties and resistance to oxidation.
For this application the Prolube system is designed to deal with the copious quantities of entrained water which may enter the system as a result of damage to bearing seals. Twin tanks and separator are incorporated in the system to facilitate removal of this and any other contaminants.


The trunnion bearings and ball mills for the mining and cement manufacturing industries utilize Prolube dual-purpose lubrication units to provide a low pressure oil supply, which is sprayed onto the journal for lubrication and cooling purposes. In addition a high pressure oil supply lifts the shaft and continuously forces the lubricant between the extremely heavy, slowly rotating shaft and the bearings.
A typical Prolube unit supplies 28 liters/min oil at 7 bars and 2 liters/min oil at up to 300 bars for each mill bearing.


The Centrifugal compressor set requires a complete pressure lubrication system to supply oil, at specified pressure and temperature, to the compressor and driver bearings, gearing,  turbine governor trip and throttle valves, control system and seal. For these duties a special Prolube lubrication console is manufactured specifically to the requirements of the appropriate petroleum standard. Illustrated over top left is a console which supplies a total of 185 liters/min of oil at 4.5 bars. This console is used in conjunction with a separate seal oil console supplying 80 to 190 liters/min of oil at pressures of 3.5 or 17.6 bar depending on the gas pressure. Combined lubrication and Seal Oil consoles are designed to run at the highest pressure which is then reduced to various levels to meet the requirements of the served equipment.


Ferrous and non-ferrous hot and cold rolling mills require large circulating systems, each designed to suit the respective demands of the product. Systems may vary in capacity from 400 to 25000 liters/min and may be designed to handle soluble oil coolants. Filtration also needs to be tailored to suit the product and may vary from a simple basket type strainer to a fully automatic earth-type filtration plant as a by-pass system to the main coolant circuit.


Prolube provide a service covering all aspects of design, fabrication and erection of pipework. The latest techniques and equipment are used for the manufacturing of pipework both at works and on site.