Q: Why should I use a Flender spec oil?
A lot of users ask about the need to use a Flender approved lubricant for their equipment! For a gear oil to be Flender approved1 in one of its units, the oil must be of CLP* quality according to DIN 51517-3 and motor oils must meet and ACEA Classification E2, API CF/SF. Additionally, it must meet the minimum requirements as per their specified “Proofs of performance / minimum requirements table” where the lubricants are tested at approved laboratories.
*CLP (according to DIN 51517-3)2 refers to an oil that contains additives which protect from corrosion, oxidation and wear in the mixed friction zone.
The manufacturer must also guarantee performance of the lubricant both for new oil and used oil up to a permissible range as per the following:
- Mineral oils (API I & II and ester oils) shall be 10,000 operating hours (2 years max)
- Mineral (API III) and Synthetic (PAO & PAG) oils shall operate for 20,000 operating hours (4 years max)
- All oil must produce the minimum requirements with an average operating temperature of 80°C
The following are a list of tests required by Flender which must produce specified minimum results:
- FZG Scuffing test in accordance with DIN ISO 14635-1 (A/8.3/90)
- FE8 rolling bearing test in accordance with DIN 51819-3 (D-7, 5/80-80)
- FVA micropitting test FV A 54 VII
- Flender oil Foam test in accordance with ISO 12152
- Compatibility with internal coating
- Compatibility with outer coating
- Filterability test FFT 7300 Rev.3
- Compatibility with liquid sealing component
Flender specifies the viscosity in the series to be tested for the minimum requirements.1
The Flender approval process ensures that the lubricant being used has been tested and can withstand some degree of micropitting, scuffing, foaming and is compatible with the surfaces in which it comes into contact. Thus, this makes the Flender approved lubricant more desirable for systems which place emphasis on the compatibility of all materials in the equipment (such as elastomers, paints etc). In conclusion, if you do have a Flender gearbox or equipment, it would be wise to use the Flender approved lubricant as they have gone the extra mile to ensure that the lubricant can protect your equipment.
Users can access a listing of approved Flender lubricants here: https://www.flender.com/en/lubricants