Document MEROdQQ0zOKBjqaoj5BjGN6j

HOT WORKING OF METALS intensity of the penetrating radiation into visible images ore X-ray film fluorescent screens, geiger porportional end window scintillation counters, and ionization gauges. All sources of ionizing radiation are po tentially dangerous X-ray and gamma ray sources may also produce hazardous sec ondary radiation In addition. X-ray units involve both low- and high-potential elec trical hazards. Full details of a radiation safety program appbcable to all industries that use radiographic testing methods are given in Chap ter 42, "Ionizing Radiation" Chapter 42 also discusses the biological effects of radi ation, gives tolerance limits, and recom mends personnel protection practices Hydraulic Fluids and Equipment sion of oil is a continuous phase of water This is a regular emulsion, and the amount of oil is much less than the amount of water h The water-m-oil emulsion is a disper sion of water in a continuous phase of oils, the water content is between 40 and 50 per cent Under pressures which range from 150 psi to over 5,000 psi, oil from a broken fit ting or leak is discharged in the form of a spray or mist, which on contact with a source of ignition is certain to result m a fire For this reason, only fire-resistant fluids should be used on operations involv ing open flames or other sources of heat, such as open pots or tanks of molten metal, and on machinery such as die-casting ma chines and welding presses Hydraulic fluids are used as the motive power for many types of mechanical equip ment The fluids are not hazardous unless part of the circuit--pipes, hose, or connec tions--fails Although water was the first fluid used in hydraulic systems, it was soon replaced by petroleum-base oils because water lacked lubricity and had a corrosive effect on me tallic machine parts In addition to mineral oils, water contain ing a water soluble oil to reduce corrosion was used Recently, fire-resistant fluids" have come into widespread use There are three basic types of fire-resist ant hydraulic fluids 1 Water-glycol fluids, which consist of gly cols with up to 50 per cent water, to gether with various additives to serve as thickeners, increase oihness, and inhibit corrosion The water makes the solu tions fire-resistant Hazards Compared to most petroleum products, fire-resistant hydraulic fluids generally, and the emulsions particularly, do not present a tone hazard and therefore do not require special handling Special precautions must be taken m the handling of some of the synthetic fluids to guard against toxicity In all such cases, however, the proper instructions are includ ed m the literature provided, and the contamers are plainly marked Producers of fire-resistant hydraulic fluids approved by the U S Bureau of Mines un der Schedule 30 (approved December 11, 1959) are required to include a caution statement on the labels affixed to the con tainers when precautions of any kind are necessary, regardless of their similarity or dissimilarity to those required for petroleum hydraulic fluids 2 Nonaqueous synthetic fluids, which gen erally have a phosphate-ester base Chlor inated hydrocarbons have also been used, alone or in combination with certain phosphate esters 3. Water-oil emulsions, which are stabibzed matures of water and oil containing emulsifying agents to accomplish proper mixing. Such fluids may contain addi tive amounts of other constituents to meet specific conditions and requirements There are two types a The oil-in-water emulsion is a disper "Also see Industrial Data Sheet 543, FireResistant Water-in-oil Emulsion Hydraulic Fluids, published by the National Safety Council ##U.S. Bureau of Mines, Department of the Intenor Schedule 30, "Fire-Resistant Hydraulic Fluids," Code of Federal Regu lations, Title 30, Mineral Resources, Part 35, Subchapter E Available from the Su perintendent of Documents, U S Govern ment Printing Office, Washington, D C 27-30