BS ISO 12921:2024 - Petroleum products and lubricants. Determination of the mechanical stability of greases in presence of water

Standard No.: BS ISO 12921:2024
Release Date: 2024
Published By: British Standards Institution (BSI) GB / BSI
Latest: BS ISO 12921:2024

Introduction

Analysis of the core content of the standard

BS ISO 12921:2024 specifies a test method for evaluating the mechanical stability of grease by comparing the change in cone penetration between dry and wet states under 10% water content. The test is divided into two stages: 60 stirring times and 100,000 extended stirring times.

Comparison of key test indicators

Test parameters	Calculation formula	Engineering significance
P60 difference	P60_wet - P60_dry	Initial influence of moisture (positive value indicates softening)
P100k difference	P100k_wet - P100k_dry	Long-term water-containing working stability
Mechanical stability index	P100k_wet - P60_Dry	Performance degradation under water conditions

Test equipment requirements

The standard clearly requires the use of full-size cones and stirrers specified in ISO 2137. The main equipment includes:

Flat-bottom mixing cup with a diameter of 200mm
Non-abrasive scraper (wood/plastic)
Balance with an accuracy of 0.1g
Slow-speed mechanical stirrer (recommended speed ≤300rpm)

Test accuracy data

According to the inter-laboratory comparison data provided in Chapter 13 of the standard:

Repeatability of distilled water test r=12, reproducibility R=40
The repeatability of the synthetic seawater test is r=22, and the reproducibility is R=53

Industry application recommendations

This standard is particularly suitable for the following scenarios:

Marine machinery: Evaluation of the long-term stability of grease in seawater environment
Mining equipment: Prediction of lubrication performance degradation under high humidity conditions
Wind turbine gearbox: Verification of the mechanical retention ability of grease under the influence of condensed water

It is recommended to conduct the DIN 51807 dynamic test and the ASTM D6138 corrosion test simultaneously during the test to obtain a more comprehensive performance evaluation.

Background of Standard Evolution

This standard integrates the test methods of NF T60-626 and ASTM D7342, and for the first time establishes a unified test framework at the international standard level. Compared with traditional static tests (such as ISO 11007), its innovations are:

Introducing 100,000 times of extended stirring to simulate long-term working conditions
Clearly distinguishing the difference in the impact of distilled water and synthetic seawater
Establishing four sets of data comparison matrices to achieve multi-dimensional evaluation

BS ISO 12921:2024 Referenced Document

ISO 2137:2020 Petroleum products and lubricants — Determination of cone penetration of lubricating greases and petrolatum
ISO 23572 Petroleum products — Lubricating greases — Sampling of greases
ISO 3696 Water for analytical laboratory use; Specification and test methods
ISO 7120 Petroleum products and lubricants; Petroleum oils and other fluids; Determination of rust-preventing characteristics in the presence of water

BS ISO 12921:2024 history

2024 BS ISO 12921:2024 Petroleum products and lubricants. Determination of the mechanical stability of greases in presence of water

Petroleum products and lubricants. Determination of the mechanical stability of greases in presence of water

BS ISO 12921:2024Petroleum products and lubricants. Determination of the mechanical stability of greases in presence of water