Hydraulic oil serves as the medium for power transmission, lubricates pumps and valves, dissipates heat and guards against wear and rusting. In UAE heavy machinery, the most popular grades are ISO VG 32, 46 and 68. Starting from the equipment manufacturer’s recommendation, operating temperature determines your position within that range.
Selecting the wrong grade will not result in a sudden breakdown. Gradually you will experience slow moving cylinders, high oil temperature, noisy pumps and worn parts. The guide below gives information on how the grade is chosen, how the temperature influences oil selection, how to keep the oil clean in a dusty environment and which BP anti-wear hydraulic oils are available with GENAVCO.
Meaning of ISO VG 32, 46 and 68
ISO VG represents viscosity grade. This figure represents the viscosity in centistokes at 40 degree Centigrade. ISO VG 46 has a value of 46 cSt at 40 degree Centigrade, ISO VG 32 has lower viscosity than ISO VG 46 whereas ISO VG 68 has higher viscosity. All three could be same oil type with same additives. Only the thickness changes.
| Grade | Relative thickness | Typically suits |
| ISO VG 32 | Thinnest of the three | Cooler-running systems, fine-tolerance machinery, some indoor equipment |
| ISO VG 46 | Middle | The most common grade for mobile and industrial hydraulics |
| ISO VG 68 | Thickest of the three | Hot-running systems and heavily loaded equipment where the manufacturer allows it |
These are general patterns, not a substitute for the equipment manual. Most manufacturers provide a viscosity chart depending upon ambient temperatures, and this is where you begin.
Which Hydraulic Oil Should Be Used: 32 or 46?
Use the one recommended by the manufacturer depending upon your ambient temperature. In case where both are allowed, it depends upon how hot the oil becomes. Oil viscosity decreases with temperature. In summer in the United Arab Emirates, hydraulic reservoirs of excavators, loaders, and forklifts may operate at elevated temperatures for a long time, and a thin oil operating at elevated temperatures may not be able to maintain an adequate lubrication film in pumps and motors. This is why heavier oils are recommended for such climates.
Definition of Anti-Wear (HM / HLP)
- Anti-wear additives: These types of oil are formulated with additives to prevent pump wear at high pressures. The BP product line uses stabilized zinc additives.
- DIN 51524 Part 2: a popular German standard for anti-wear hydraulic oils, designated as HLP.
- ISO 6743/4 type HM: the internationally recognized standard for anti-wear mineral-based hydraulic oils.
- Vickers vane pump test: an accepted method to test anti-wear properties of an oil towards a vane pump.
The BP Hydraulic Oil Range From GENAVCO
| Product | Grade | Key points |
| BP Energol HLP-Z 32 | ISO VG 32 | Highly refined mineral oil, HLP and HM classified, meets DIN 51524 Part 2 |
| BP Hydraulic Oil 46 | ISO VG 46 | Anti-wear mineral oil, Vickers vane pump test, DIN 51524 Part 2 |
| BP Hydraulic Oil 68 | ISO VG 68 | Same anti-wear performance in the heavier grade |
1. BP Energol HLP-Z 32
- Confirmed specification: highly refined mineral oil with stabilized zinc additive package, belonging to DIN 51502 HLP and ISO 6743/4 grade HM and conforming to DIN 51524 Part 2.
- Confirmed benefits: offers good anti-wear, anti-corrosion performance, good oxidation resistance and water separability, is compatible with nitrile, silicone and Viton seals.
2. BP Hydraulic Oil 46 and 68
- Specification verified: mineral oils with stabilised zinc additive system that passed the Vickers vane pump test and conform to DIN 51524 Part 2 standards, type HLP and ISO 6743/4 type HM.
- Advantages verified: wear resistance reducing downtime, oxidation resistance extending lifespan, and water separation capability.
Not sure which hydraulic oil grade your fleet needs?
Send us the machine makes and models and how they are used. Our lubricants team will match each one to the right BP grade.
What Other Applications are there for Hydraulic Oil?
BP states that its hydraulic range also suits lightly loaded gears and circulating oil duties where a rust and oxidation inhibited oil is needed. It cannot be used as a substitute for gear oil in axle assemblies and other heavily-loaded gear boxes where extreme pressure additives are needed.
Maintenance of Clean Hydraulic Oil in UAE
- The biggest enemy is dust, which gets into the system via breather units, worn seals, or any unprotected containers, and which wears down pumps faster than almost anything.
- Keep up good topping procedures: use closed containers, funnels and filtration; never use an open drum on-site.
- Install proper breather units and filters, and change them according to schedule, especially when working in dusty environments.
- Take care of the temperature level: check the cooling systems and keep radiators clean so the oil doesn’t get too hot.
- Sample the oil: analysis shows wear metals, water and oxidation before they cause a failure, and supports a proper excavator maintenance checklist.
Indicators That Your Hydraulic Oil Needs Servicing
- Milky/oily appearance of oil: water contamination.
- Dark oil and a burnt odor: over-heating and oxidation.
- Foaming in the reservoir: entry of air or use of wrong oil.
- Sloppy actions and loud pump: possible issues with viscosity and contamination. These are common signs your forklift needs maintenance too.
How to Select Hydraulic Oil for Your Machinery?
- Step 1 - See what type of oil your machine needs by consulting its manual.
- Step 2 - Determine the environmental conditions: temperature, time worked daily and loads.
- Step 3 - Make sure the seals are compatible with that oil.
- Step 4 - Have a common grade wherever possible within the same manufacturer.
- Step 5 - Never mix oils without verifying compatibility.
- Step 6 - Decide the oil changing cycle and have a sample system in place.
GENAVCO: Your Choice for Hydraulic Oil
- GENAVCO lubricants department provides Genuine BP lubricants such as hydraulic, gear and engine oils. See GENAVCO lubricants.
- One-stop-shop for equipment and lubricant expertise: The company not only provides the equipment, but also the oils that go into these machines.
- Member of Juma Al Majid Group since 1967: A UAE supplier with ISO 9001 accreditation.
Hydraulic Oil Errors that are Commonly Made
- Oil selected according to cost and not specification: oil which fails to meet the needed specification will cause additional wear.
- Refilling the system with whatever oil is available: mixture of different grades/brands will affect viscosity and additive performance.
- Neglecting temperature: system running at high temperature requires checking of cooling and grade.
- Extending intervals for changing contaminated oil: contamination causes the problem and not necessarily the age. Read about the real cost of equipment downtime.
Frequently Asked Questions
What is hydraulic oil used for?
It is used to transfer power through hydraulic systems, to lubricate the pumps, valves, and cylinders, to remove heat and protect metal parts from friction and corrosion.
What is the difference between hydraulic oil 46 and 68?
Viscosity. Hydraulic Oil ISO VG 68 is more viscous than Hydraulic Oil ISO VG 46 at the same temperature.
What are some applications of ISO 32 hydraulic oil?
Hydraulic systems which are operating at cooler temperatures or require thin oil due to quick response times and tight tolerances as recommended by the equipment manufacturer. BP Energol HLP-Z 32 is an ISO VG 32 anti-wear hydraulic oil.
Is it okay to blend two different kinds of hydraulic oils?
It is not recommended. Mixing grades will alter viscosity and mixing brands may alter the effectiveness of the additives.
Choosing Your Hydraulic Oil Ready?
Start with the manufacturer's grade, check how hot your systems really run, and keep the oil clean. GENAVCO supplies the BP lubricants range across the UAE, with advice matched to the equipment you operate.
Tell us your equipment and working conditions. We will recommend the right BP hydraulic oil and price it properly.
Serving Dubai, Abu Dhabi, Sharjah and the wider UAE.
