Grease Water Washout Tester

What is the Grease Water Washout Tester?

A grease water washout tester spins a grease-packed bearing in a housing while a jet of water hits it at a set temperature. It measures the percentage of grease washed out in one hour, giving water resistance for bearing and wheel applications under ASTM D1264.

Overview

A ball bearing packed with 4 g of grease is mounted in a housing with a shield and spun at 600 rpm. A water jet at 38 or 79 °C impinges at about 5 mL per second for one hour. The water, grease and housing are then dried and weighed, and the percent of original grease lost is reported. The tester consists of a motor, bearing housing with drain, heated water reservoir and pump, and flow control. Greases with good water resistance lose under 10 percent, while some soaps wash out completely. Results support selection for wet, marine, mining, automotive and paper machine applications, and for comparing additive and thickener systems.

How does it work?

Grease is a dispersion of a thickener, such as lithium or calcium soap, polyurea or clay, in base oil with additives. Its behavior is non-Newtonian, so tests measure structure rather than viscosity. Consistency is measured by letting a standard cone sink into the sample for five seconds and reading the penetration depth in tenths of a millimeter, usually after working the grease in a standard worker. Dropping point is the temperature at which the first drop falls from a heated cup, indicating thermal limit of the thickener structure. Oil separation measures how much base oil bleeds through a wire cone under storage conditions. Oxidation tests heat grease in oxygen and record pressure drop, and water washout tests spray or immerse grease to find the percentage lost. Standard cup, cone and temperature geometry give comparable results.

What are the key features?

• Bearing housing with shield and drain
• Heated water reservoir with temperature control
• Flow-controlled water jet at 5 mL/s
• Motor-driven spindle at 600 rpm
• Timer for 60-minute test

What are the technical specifications?

A typical grease water washout tester configuration offers spindle speed of 600 ± 30 rpm, water temperature of 38 °C or 79 °C (ambient to 90 °C), water flow of ≈ 5 ± 0.5 mL/s, test duration of 60 min, grease charge of 4 g and test bearing of Ball bearing, specified dimensions. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Grease Water Washout Tester is used in marine and wet-environment grease selection, wheel bearing and chassis grease testing and paper machine and mining grease qualification. Across the wider Grease Testing class, laboratories also deploy it for grease batch quality control, NLGI grade determination and high-temperature grease development.

Which standards and certifications apply?

Relevant standards and methods include ASTM D217, ISO 2137, ASTM D566, ASTM D2265, IP 396, ASTM D942, ASTM D1264 and ASTM D6184. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Grease tests are sensitive to sample handling. Fill cups without air pockets, and bring samples to 25 °C in a bath before penetration testing. Keep cones and worker plates clean and undamaged, and verify penetrometer zero and cone mass and dimensions. Calibrate temperature sensors in dropping point blocks. For oxidation bombs, check pressure transducers and leak tightness, and treat oxygen with care: use clean, oil-free regulators and a ventilated area. Replace consumables such as wire cones and cups per the method. Keep grease waste separate from solvents, and record reference grease checks with certified materials to support laboratory accreditation.

How do I select the right Grease Water Washout Tester?

Choose a water washout tester when greases serve in wet service such as marine, paper mills or mining. Specify water temperature range, bearing housing design, flow control, timer and whether spare bearings are supplied. It does not assess corrosion protection, which needs separate tests.

How does it compare with other Grease Testing variants?

Choose equipment according to the grease properties in your product specification. Every grease plant needs a penetrometer and grease worker for NLGI grade, plus a dropping point apparatus. Formulators of high-temperature and long-life greases add oxidation stability testing. Storage and bearing-application tests such as oil separation and water washout support quality control and complaint handling. Consider whether the penetrometer needs automatic operation, full-scale or quarter-scale cones, and heating capacity for the dropping point block, which is often 260 to 400 °C for high-temperature greases. Check compatibility with the standard edition cited by customers, and whether consumables such as wire cones, cups and wheel bearings are available. In the RFQ, list methods, sample throughput and the thickener types tested.