Barrierta L 55/1 vs Barrierta L 55/2: PFPE High-Temperature Grease Grade Selection
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Barrierta L 55/1 or Barrierta L 55/2?
Same chemistry, different consistency. Both are white PFPE greases with PTFE solid lubricant, NSF H1 registered and suitable to 260 °C, and both carry the same base oil viscosity of about 420 mm²/s. L 55/1 is NLGI 1 with a four-ball welding load of at least 7,000 N; L 55/2 is NLGI 2 with at least 8,000 N, and Klüber's product information names L 55/2 as the grade most frequently used for initial and long-term lubrication, with softer grades (NLGI 1 or lower) recommended for relubrication. Choose by point type: initial fill and firm retention point to L 55/2, relubrication-friendly or softer points to L 55/1.
The two grades side by side
| Property | BARRIERTA L 55/1 | BARRIERTA L 55/2 |
|---|---|---|
| Base oil | PFPE (perfluorinated polyether) | PFPE (perfluorinated polyether) |
| Solid lubricant | PTFE | PTFE |
| NLGI grade, DIN 51818 | 1 | 2 |
| Service temperature | -40 to +260 °C | -40 to +260 °C |
| Base oil kinematic viscosity at 40 °C | approx. 420 mm²/s (approx. 40 at 100 °C) | approx. 420 mm²/s (approx. 40 at 100 °C) |
| Shear viscosity, 25 °C at 300 s⁻¹ | 4,000 to 8,000 mPas | 8,000 to 12,000 mPas |
| Four-ball welding load, DIN 51350 pt. 04 | ≥ 7,000 N | ≥ 8,000 N |
| Speed factor (n × dm) | approx. 300,000 mm/min | approx. 300,000 mm/min |
| SKF-EMCOR, distilled water, 1 week | ≤ 1 corrosion degree | ≤ 1 corrosion degree |
| NSF H1 registration | 129 561 | 129 400 |
| US food regulation | complies with FDA 21 CFR Sec. 178.3570 | complies with FDA 21 CFR Sec. 178.3570 |
| Hygienic manufacture | ISO 21469 certified | ISO 21469 certified |
| Density at 20 °C | approx. 1.95 g/cm³ | approx. 1.96 g/cm³ |
| Colour | White | White |
| Minimum shelf life, unopened, dry and frost-free | approx. 60 months | approx. 60 months |
| Pack sizes | 800 g cartridge, 1 kg can, 10 kg bucket | 800 g cartridge, 1 kg can, 10 kg bucket |
Scroll the table horizontally to view all columns.
Source: Klüber product information BARRIERTA L 55 series (Prod. 090014, 090013, 090035, 090042) and the Klüber product page for BARRIERTA L 55/1. Klüber publishes these values as guide values; confirm against the datasheet supplied with your delivery.
What PFPE buys you at high temperature
The PFPE base oil is the point of the series. Conventional greases evaporate and oxidise away in oven chains and kiln bearings; the perfluorinated structure barely evaporates, which is what lets Klüber document service to 260 °C with long relubrication intervals. The same chemistry ignores most aggressive media: the product information names concentrated acids, lyes, organic solvents and gases as exposure the greases tolerate. And because PFPE is chemically inert toward most plastics, the series also fits plastic/plastic friction points, unusual for a grease this load-capable.
The trade-offs are real. PFPE greases cost far more per kilogram than mineral oil products, and their density of about 1.95 g/cm³ means a fill specified by volume puts roughly twice the mass in the point compared with a normal grease. They also do not mix with hydrocarbon greases, so a changeover is a clean-out job, not a top-up.
Where the series is documented in use
Klüber documents the L 55 series for rolling and plain bearings and guides under extreme temperatures, with named applications including:
- Conveyors (load and turn rollers) and kiln cart wheel bearings
- Calender bearings
- Automatic baking ovens, cooking and frying lines
- Fan bearings and chain bearings in film stretching stenters
- Valves, fittings, pneumatic components, level gauges and seals, including in the chemical industry
On food machinery: all L 55 grades are NSF H1 registered with ISO 21469 certification, so they can be used where incidental contact with food products cannot be ruled out, for example on oven chains above open product. Klüber still recommends a risk analysis such as HACCP, and the registration should be verified in the current NSF White Book.
Example: an oven chain conversion
A baking oven chain lubricated with a high-temperature lithium grease needs relubrication every shift because the grease carbonises near 200 °C. The conversion that the documentation supports: clean the chain with white spirit, flush with Klüberalfa, dry with hot air, charge L 55/2 for the initial fill (the documented initial and long-term grade), then move shift relubrication to a much longer interval based on measured chain wear. Where relubrication continues at shorter intervals, Klüber's guidance to use the softer NLGI 1 (L 55/1) applies instead.
Surface preparation and relubrication
The product information is specific about preparation because PFPE will not blend with what it replaces: clean friction points with white spirit, then with Klüberalfa XZ 3-1, and dry with clean compressed air or hot air so no solvent remains. The point must be free of old oil, grease and contamination before the initial fill. For relubrication intervals on an existing PFPE point, follow the machine builder or ask for Klüber's application engineering support, since intervals at 260 °C depend on load and exposure that datasheets cannot predict.
Common questions
Which grade for a first fill?
L 55/2 is the grade the product information names as most frequently used for initial and long-term lubrication, and its higher weld load and firmer body suit points that must hold grease under vibration. For points that will be regreased regularly, the same document recommends the softer grades, NLGI 1 or lower, which is where L 55/1 fits.
Are they food safe?
They are H1 registered, which covers incidental, technically unavoidable food contact at limited concentration. That is a different thing than edible, and it does not replace the plant's HACCP controls. Verify the registration in the current NSF White Book for the batch you buy.
Can I mix L 55 with the grease already in the bearing?
No. PFPE and hydrocarbon oils are not miscible, and Klüber's preparation instructions call for a complete clean-out with white spirit and Klüberalfa before the first PFPE fill. Plan a purge, not a top-up.
Why does the grease feel heavy and dense?
PFPE base oil has a density near 1.95 g/cm³, roughly double a mineral oil's. Dosing pumps and fill quantities specified in millilitres deliver nearly twice the mass with L 55 compared with a normal grease. Check fill specifications by mass where the point is volume-critical.
Which grade suits plastic gear trains near heat?
Both grades are neutral toward most plastics per the product information, and Klüber recommends a compatibility test before series use. Between the grades, pick by consistency and lubrication method as above; the plastic compatibility is a series property, shared by L 55/1 and L 55/2.
Order Barrierta L 55/1 or L 55/2
Send the grade, pack size (800 g cartridge, 1 kg can or 10 kg bucket) and quantity. If you are converting a point from a conventional grease, mention the current product so we can include the changeover notes with the quotation.
Manufacturer references
- Klüber product page: BARRIERTA L 55/1
- Klüber product information: BARRIERTA L 55 series (articles 090013, 090014, 090035, 090042)
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