High-Temperature Foaming Characteristics

Description

Evaluates the tendency of oil to form stable foam at high operating temperatures (150 °C), which is critical for preventing cavitation and oil starvation.

Foam in a lubrication system is air, and air does not lubricate parts. Expert analysis of high-temperature foaming from RENA is a preventive measure for heavily loaded transmissions, hydraulic systems, and high-speed engines, where intense agitation of hot oil can cause it to foam. We will help you avoid situations where excessive foam leads to pressure drops in the system, overheating of mechanisms, and their catastrophic wear due to dry friction. The test is conducted under conditions closely approximating real extreme operation (ASTM D6082). The oil sample is heated in a special graduated glass cylinder to a temperature of 150 °C. Once temperature balance is achieved, a flow of dry standardized air is introduced into the oil through a spherical gas diffuser at a rate of 200 ml/min for 5 minutes. This process provokes the intense formation of air bubbles within the fluid volume. The instrument records two key parameters: the total foam volume immediately after shutting off the air supply (foaming tendency) and the foam volume after 10 minutes of static settling (foam stability). High temperatures significantly complicate the performance of anti-foam additives (defoamers), so this test reveals the actual chemical stability of the additive package under conditions where standard tests at 24 °C and 93.5 °C might show normal results.