BS ISO 11009:2021 pdf download – Petroleum products and lubricants — Determination of water washout characteristics of lubricating greases
1 Scope
This document specifies a method for evaluating the resistance of a lubricating grease to washout by water from a bearing, when tested at 38 °C or 79 °C under specified laboratory test conditions. This test method estimates the resistance of greases to washout from ball bearings under specified conditions. No formal correlation with field service has been established so far. This document is used for development and specification purposes.
NOTE For the purposes of this document, the term “% (m/m)” is used to represent the mass fraction.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 15, Rolling bearings — Radial bearings — Boundary dimensions, general plan
ISO 1998-1, Petroleum industry — Terminology — Part 1: Raw materials and products
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 23572, Petroleum products — Lubricating greases — Sampling of greases
3? Terms? and? definitions
For the purposes of this document, the terms and definitions given in ISO 1998-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
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4 Principle
A test portion of grease is packed in a ball bearing inserted in a housing with specified clearances. The bearing is rotated at 63 rad/s ± 3 rad/s (600 min −1 ± 30 min −1 ). Water, controlled at a specified test temperature, impinges on the bearing housing from a nozzle with a diameter of 1 mm, at a rate of 5 ml/s ± 0,5 ml/s. The distance between the end of the nozzle and the shield of the housing is 57 mm. The water jet is set to strike the bearing 6 mm ± 2 mm above the upper edge of the shield. The amount of grease washed out in 60 min ± 5 min is a measure of the resistance of the grease to water washout.
In addition, the washer fixed at the end of the rotating shaft shall be very well centred to ensure the 0,8 mm circular clearance with the shield. For that purpose, use a fitting screw, with a non-threaded part crossing the washer, the diameter of the non-threaded part being equal to that of the hole in the middle of the washer. See Figure A.2.
9 Operating procedure
9.1 Carry out the test in duplicate. Fill the tared bearing (6.2) with 4,00 g ± 0,05 g of test grease, equally distributed over the bearing. Insert the bearing and tared shields into the housing, and assemble the unit in the test apparatus. Record the mass of the bearing, shields and grease, to the nearest 0,01 g.
9.2 Add a minimum of 750 ml of preheated water (7.2) to the reservoir, but keep the water level below the bearing housing by means of a piece of tubing attached to the capillary discharge tube (key 4 on Figure A.1) or with a deflecting metal shield, until equilibrium temperature is attained. When the test is to be carried out at the higher temperature of 79,0 °C ± 1,7 °C, bring the water to the specified temperature by a previously selected source of heat. If the rig has one motor driving both the pump and test bearing, remove the belt from the test-bearing spindle pulley during the water warm-up time.
9.3 When the water reaches the specified temperature, adjust the by-pass valve to give a water-flow rate of 5 ml/s ± 0,5 ml/s through the piece of tubing fixed on the capillary discharge tube and into the graduated cylinder (6.3). Determine the flow rate from the volume of liquid flowing into the cylinder over a period of 10 s, as measured with the timer (6.4). Remove the piece of tubing from the capillary discharge tube, and adjust the water jet so that it impinges on the shield 6,4 mm above the annular opening.
9.4 Start the test and continue operation for 60 min ± 5 min from the moment when the rotational speed of the bearing reaches 63 rad/s ± 3 rad/s.
9.5 Shut off the motor and the heating source, if used. Remove the test bearing and shields and place them on a tared watch glass (6.5). The shields shall be separated from the bearing and placed with their inner faces upward to expose the wet grease to the air.
9.6 Dry the bearing and shields for 15 h at 77 °C ± 6 °C (see NOTE) in the oven (6.7), and then weigh to the nearest 0,01 g to determine the grease mass loss. The grease remaining on the shields, and any leakage occurring during the drying period, should not be considered as grease mass loss.
NOTE In some cases, a mass increase and not a mass loss, can be noted. The origin can be building up of stable grease – water emulsion, from which the water cannot be evaporated in the foreseen drying conditions. The drying temperature should be increased to 93 °C ± 3 °C for greases containing high-viscosity oils, to facilitate removal of water during the time period specified.BS ISO 11009 pdf download.