Wouldn’t it be great if there was a single list you could consult to help you pick the right hydraulic fluid for your equipment?
Unfortunately, fluid selection is not as simple as we’d like. Every application is different, and you need to pay attention to equipment manufacturers’ requirements, specifications, and recommendations as well.
There are a few steps you can follow to help make your choice. First, determine the type of equipment where you will use the fluid. Second, consider the severity of the duty cycle. And third, determine what temperatures the equipment will experience during use.
Viscosity, antiwear levels are key in industrial use.
Industrial hydraulic systems in normal service indoors generally use a conventional antiwear- type hydraulic fluid with appropriate viscosity. Choosing the right viscosity fluid is important because it ensures the system’s best overall performance and that the components are protected. The antiwear agents contained in the oil protect the hydraulic pump components from premature wear.
Different fluids for changing needs
The challenge is different with mobile equipment — used for off-road construction, timber harvesting, municipal waste and utilities, for example. Mobile equipment can see high pressures, severe duty cycles, and wide temperature extremes during year-round use in areas with seasonal climates. Their fluid needs to work well at low temperatures for winter time start up, while maintaining enough viscosity at high temperatures to protect during severe service or hot weather.
The ideal hydraulic fluid for mobile applications is one that flows like a lighter oil at low temperatures but protects like a heavier oil at high temperatures: a multigrade hydraulic oil. This is similar to using SAE 5W-30 or 10W-30 multigrade engine oil in our cars, which can be used year-round without problems.
Multigrade and conventional fluids
What differentiates multigrade hydraulic fluids from conventional fluids is that they contain polymer additives, called viscosity modifiers (VM) — also known as viscosity index improvers — in addition to the hydraulic performance package. These VMs keep the fluid viscosity more consistent over the temperature range encountered during use.
Multigrade fluids are also known as high viscosity index (VI) fluids. VI is a measure of how much a fluid’s viscosity changes with temperature. A higher VI number means the viscosity changes less as the fluid heats and cools, which is desirable. Conventional fluids typically have VI around 100. By comparison, a multigrade fluid should have VI of at least 140. There are fluids with VI higher than 200 for use in such temperature extremes as the Arctic or where viscosity must remain steady across a wide temperature range.
Perks of multigrade fluids
Five of the benefits of using a good-quality, high VI-multigrade fluid are that it:
- Maintains a more consistent viscosity as temperature changes, so the system continues to perform properly.
- Flows better at low temperatures for improved cold-weather operation. The equipment will experience fewer problems with cavitation, sluggishness, drift, or shudder.
- Maintains viscosity at high temperatures to protect system components and maintain overall efficiency.
- Provides greater mechanical and volumetric effectiveness, which improves energy efficiency and reduces fuel consumption.
- Can be used year-round and over wide temperature ranges.
Operating within the recommended viscosity range helps ensure that equipment is protected and that it operates most efficiently.
XHVI 32 HYDRAULIC OIL (Semi Synthetic)
Extreme range Multigrade hydraulic oil, single product all year use in the most demanding hydraulic systems.
Pours like a ISO 22 and protects like a ISO 46
Pour point -42
HVI (High Viscosity Hydraulic Fluids)
Wide temperature range, High performance hydraulic fluids.
Full viscosity range 13, 22, 32, 46, 68, 100
Anti-wear A/W Hydraulic fluids
Mono grade hydraulic fluids designed to meet hydraulic equipment OEM specification.
Viscosity grade selection 22, 32, 46, 68, 100
Zinc Free HVI 32 (Inherently Biodegradable)
Wide temperature range, high performance for use where zinc free ash-less hydraulic fluids are required.