This SAE Aerospace Recommended Practice (ARP) provides a procedure for obtaining filter patch test samples from the following types of aerospace non-rotating hydraulic equipment: Mechanical/Hydraulic Units Electro/Hydraulic Units Pneumatic/Hydraulic Units
Although there is controversy regarding the chemical form of chlorine and its relation to harmful effects in the hydraulic fluid (i.e., chloride ions versus organic chloro-compounds versus total chlorine in all forms), it is generally agreed that total chlorine content should be measured and controlled. In the near future, the ban on the manufacture of chlorinated solvents, out of concern for depletion of the ozone layer, may in itself diminish or eliminate chlorine contamination related aircraft malfunctions. It is generally accepted that hydraulic fluid contamination should be held to a minimum under all conditions. The benefits of low contamination levels are improved performance, lower maintenance due to lower wear, corrosion and erosion, longer fluid life, longer component life, etc. Contaminants can be classified into two general types: those that are insoluble and those that are soluble in the hydraulic fluid.
Although there is controversy regarding the chemical form of chlorine and its relation to harmful effects in the hydraulic fluid (i.e., chloride ions versus organic chloro-compounds versus total chlorine in all forms), it is generally agreed that total chlorine content should be measured and controlled. In the near future, the ban on the manufacture of chlorinated solvents, out of concern for depletion of the ozone layer, may in itself diminish or eliminate chlorine contamination related aircraft malfunctions. It is generally accepted that hydraulic fluid contamination should be held to a minimum under all conditions. The benefits of low contamination levels are improved performance, lower maintenance due to lower wear, corrosion and erosion, longer fluid life, longer component life, etc. Contaminants can be classified into two general types: those that are insoluble and those that are soluble in the hydraulic fluid.
This SAE Aerospace Standard defines cleanliness levels for particulate contamination of hydraulic fluids and includes methods of reporting data relating to the contamination levels. The contamination levels selected are an extension and simplification of the widely accepted NAS 1638.
This SAE Aerospace Standard defines cleanliness levels for particulate contamination of hydraulic fluids and includes methods of reporting data relating to the contamination levels. The contamination levels selected are an extension and simplification of the widely accepted NAS 1638.
This test method describes a procedure for determining the insoluble contamination level of the downstream side of filter elements. Results of this procedure are intended to be used only for evaluation of the effectiveness of various cleaning treatments, or cleanliness of element as received from manufacturers. The data obtained by this procedure do not necessarily indicate, qualitatively or quantitatively, the contamination which may be released by a filter element into a fluid during service use. Because of the wide variety of conditions which may exist in service applications, it is recommended that the user design and conduct his own particular service performance test. (See paragraph 10.1).