Air release properties of lubricants and hydraulic oils – New Seta instrument offers safer and easier testing

Lubricating oils are not completely free of air and during operation and storage are constantly in an exchange process with their air-containing environment. Whilst an oil sample may appear free of air bubbles, a proportion of invisible dissolved air can be present. The amount of dispersing additives, the oil’s density and any impurities also impact on the volume of entrained air that an oil sample may contain.

A lubricant containing excessive amounts of entrained air can be the cause of serious disruptions in equipment operation, increasing oxidation tendency and shortened lubricating efficiency. Potential problems include severe deterioration of fluid quality, decreased lubricity and mechanical noise, often ending in the unwanted expense of equipment downtime and costly repairs.

The new Seta Air Release Value Apparatus (ARV) determines the time taken for hydraulic fluids and lubricating oils to release entrained air and gases. Tests are performed in accordance with ASTM, IP and ISO methods where a sample is heated and subjected to airflow at a specified rate while the instrument measures and records the time needed for entrained air to reduce in volume, this is determined as the ‘air bubble separation time’.

Traditional Air Release testing requires the use of several different components and is heavily operator dependent; the new integrated Seta ARV instrument automates and greatly simplifies test procedures.

The heated test sample is raised up over a weighing ‘sinker’ which is permanently fixed in position and overcomes the risk of dropping it into the hot sample, a common problem when tests are made using traditional apparatus. The new instrument has an integral test vessel platform that allows the hot sample to be quickly and precisely moved between test modes without effort or risk to the operator.

The new instrument also incorporates a number of enhanced operator safety features. The automatic test process means there is no need to handle hot glass vessels, whilst a protective safety shield around the vessel during aeration reduces risk of accident. An exhaust filter system extracts noxious fumes emitted by the test sample, an air flow interlock prevents heating when there’s no air flow and a safety cut-out prevents overheating.

The Seta ARV automates test interval timing and regulates aeration which ensures that stable density and test repeatability is achieved whilst providing enhanced test throughput with less onus or risk to the operator.

For more information about the new Air Release Value instrument please visit www.stanhopeseta.co.uk or contact marketing@stanhope-seta.co.uk.

About Stanhope-Seta: Stanhope-Seta design and manufacture quality control instruments used to measure the physical characteristics that determine product quality. Seta instruments are used by many diverse industries including oil refining, petrochemical, lubricants, pharmaceutical, food, cosmetics, plastics and transport.