How to choose oil for pumps?
Oil is one of the essential components for the proper operation of a high-pressure piston pump: it lubricates moving parts, helps dissipate the heat generated during operation, and protects the internal mechanics from wear. Choosing the right oil and changing it at the right intervals is therefore critical to the pump's service life and reliability. On this page, we explain what type of oil should be used in piston pumps, how to read the SAE grade and viscosity, what criteria to follow when choosing the right oil for an industrial pump, and how to handle oil changes correctly.
Why oil is an essential component of the pump
Inside the crankcase of a piston pump, oil performs several functions at once: it reduces friction between moving parts, helps dissipate the heat produced during operation, and forms a protective film that limits wear on mechanical components. For this reason, HAWK considers oil a key element of the maintenance plan and recommends checking it daily using the sight glass or the dipstick.
HAWK pumps are supplied with their initial oil fill and a sealed cap. Before startup, this cap must be replaced with the vented breather cap supplied with the pump.
What type of oil should be used in high-pressure piston pumps?
For its high-pressure piston pumps, Leuco S.p.A. recommends a SAE 10W-40 multigrade oil, as indicated on the pump nameplate. This oil provides stable lubrication across a wide temperature range, a critical requirement for components that run at high speeds and under continuous stress.
The specification on the nameplate always takes priority: using only the oil recommended by the manufacturer is the most important rule for maintaining performance and keeping the warranty valid.
How to read the SAE grade and oil viscosity
Viscosity indicates the oil's resistance to flow and is the parameter that determines whether an oil is suitable for the operating conditions. In general, higher-viscosity oils are better suited to summer use and high temperatures, while lower-viscosity oils perform better in cold conditions and winter use.
Multigrade oils, such as SAE 10W-40, adapt to changing temperatures and cover both conditions. The designation consists of two numbers separated by the letter "W" (winter): the first number describes low-temperature behavior, and the second describes high-temperature behavior. The result is good flow at low temperatures, which makes cold starts easier, and a reliable lubricating film even during critical startup phases and at full operating speed.
How to interpret the designation of a SAE 10W-40 multigrade oil
|
Designation element |
What it indicates |
Why it matters when choosing |
|
SAE |
Viscosity classification standard |
Allows oils from different manufacturers to be compared on a consistent basis |
|
10W |
Low-temperature viscosity (W = winter) |
Ensures good flow and easier cold starts |
|
40 |
High-temperature viscosity |
Maintains the lubricating film at operating temperatures |
How to choose the right oil for an industrial piston pump
Choosing oil for an industrial piston pump is never a random decision and should always start from a specific reference: the specification on the nameplate and in the operation and maintenance manual. Alongside this basic criterion, there are a few practical considerations related to the application:
- - strong>Temperature conditions: very cold or very hot environments point toward the most suitable multigrade oil specified by the manufacturer.
- - Workload and duty cycle: heavy-duty or continuous use requires shorter oil change intervals.
- - Compliance with safety data sheets: oils, lubricants, and cleaning products must be used in accordance with the manufacturer's safety data sheets.
In short, the right oil for an industrial pump is the one recommended by the manufacturer, combined with a maintenance plan tailored to the pump's actual operating conditions.
How often to change the oil and how to do it correctly
Even the best oil loses effectiveness over time, which is why scheduled oil changes are an integral part of proper piston pump maintenance. HAWK recommends performing the first oil change after the first 50 hours of operation and subsequent changes every 500 hours, and in any case changing the oil once a year even if the pump has not reached 500 hours.
To change the oil correctly, simply place the pump on a level surface, remove the drain plug to fully drain the used oil, and refill with new oil up to the level shown on the sight glass or dipstick. Use only the oil specified on the nameplate, and dispose of used oil in compliance with applicable environmental regulations.
It is also good practice to check the oil level and condition daily: traces of emulsion (milky-looking oil) indicate water contamination and call for an inspection of the seals and, if necessary, replacement with genuine spare parts.
Choosing and maintaining the right oil is the simplest and most cost-effective way to extend the life of a piston pump: a SAE 10W-40 multigrade oil, the nameplate as your reference, and an oil change schedule based on actual use. To learn more about maintenance, find genuine spare parts, or get help choosing the right pump for your application, the HAWK team is here to help.
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