Be sure to check out the mainstream products of flame retardant hydraulic oil! Otherwise, you can't keep up with the rhythm!
January 25, 2022
Hydraulic devices are widely used and of various types, occupying a large share in industrial lubricating oils. Hydraulic oil is generally based on mineral oil, but in the high temperature, high pressure or near open flame hydraulic equipment in metallurgy, thermal processing, coal mining and other industries, if mineral oil type hydraulic oil is used, it may cause fire due to oil leakage. In order to prevent fire caused by oil leakage, the hydraulic equipment in these occasions requires the use of fire-resistant hydraulic medium, that is, flame-retardant hydraulic fluid. Flame-retardant hydraulic fluids mainly include water-soluble products and anhydrous (synthetic) products. Water-soluble products include water emulsion products and water-glycol products, and synthetic products include phosphate ester products and Polyol ester products, etc.
1. Development status of flame retardant hydraulic oil Emulsions and polymer-containing aqueous solutions are still the mainstream products Mineral oils are used in most hydraulic systems, but in some special applications such as furnaces, forgings, steel mills and welding, any leaks or spills can cause a fire. Since World War II, some products have developed to be safer alternatives to mineral oils. Some of them, such as PCBs, are no longer used for health and environmental reasons. Now, the International Organization for Standardization (ISO) has identified four major classes of fire resistant hydraulic fluids (FRHFs), and has developed codes for each class according to their chemical properties; HFA stands for high water hydraulic fluids; HFB stands for water in oil type hydraulic fluid; HFC stands for water glycol hydraulic fluid; HFD stands for synthetic or "anhydrous" hydraulic fluids, including synthetic ester types.
2. Synthetic products are developing rapidly HFD type hydraulic oil, there are several types of hydraulic oil in this category, those that do not contain mineral oil and water can be called synthetic type. Phosphate ester hydraulic oil is the first member in the big family of HFD type hydraulic oil, and it is the most flame-resistant. But now it is used less and less, mainly due to the lack of environmental protection, poor compatibility, and high cost. Phosphate ester hydraulic oil is still used in some specific occasions because of its high auto-ignition temperature, such as aircraft manufacturing and power plants. Most phosphate ester flame retardant hydraulic fluids have been replaced by fatty acid ester flame retardant hydraulic oils. Because it is an organic ester, the fatty acid ester fire-resistant hydraulic oil has a good fire-resistant type and is the most common HFD-type fire-resistant hydraulic oil. They have excellent compatibility with various system accessories, are fully compatible with mineral oils and are suitable for high pressures. In addition, due to its organic nature, the product has good biodegradability, is non-toxic and harmless, and is very environmentally friendly. The price of fatty acid ester fire-resistant hydraulic oil is more than two times higher than that of ordinary mineral oil type hydraulic oil, so it is only used in some occasions where fire resistance and biodegradability are required. The common Base Oil of HFD hydraulic oil is pentaerythritol oleate, trimethylolpropane oleate, etc. Other types of synthetic fire-resistant hydraulic fluids are designed for certain specific applications. Anhydrous polyether fire-resistant hydraulic oil has a long service life and is very environmentally friendly. Silicone oil is used in some key occasions, but these types of synthetic fire-resistant hydraulic oil are very expensive and their application is restricted. 3. The proportion of synthetic ester products is increasing Synthetic ester type flame retardant hydraulic oil is mainly polyol ester type hydraulic oil (polyol ester, also known as fatty acid ester type, HFDU type flame retardant hydraulic oil), which is prepared by high-performance synthetic ester and selected additives , It has the anti-corrosion protection effect of ferrous metal and non-ferrous metal, and has excellent oxidation stability. Because of its high self-ignition point, it is used in special industries such as aviation, electric power, iron and steel metallurgy, etc. Polyol ester hydraulic oil has good compatibility with hydraulic system materials and is compatible with most sealing materials, especially Yes: nitrile rubber, fluorine rubber, teflon, silicone rubber, urethane (URETHANE). However, the following seals are best not to use: neoprene, butyl, ethylene propylene rubber (EPR), low density nitrile rubber (Low nitrile Buna-N). At the same time, because this hydraulic fluid is easy to exchange with mineral oil type hydraulic oil, and has excellent performance, it has the advantages of good biodegradability and so on. According to the product performance introduction, the applicable temperature range of several commonly used flame-retardant hydraulic fluids, synthetic ester products have a wider temperature applicable range and higher working pressure, and are biodegradable, so although their prices are mineral oil-type hydraulic fluids It is still used in many places with higher requirements for flame retardant and environmental protection, and its application ratio is continuously increasing.
