Document LK5G9yY0LwVeM2wO8KjvmkJLg

Principles of Materials Handling and Storing walk beneath them, drip pans should be in stalled and provided with drainage to a safe disposal or recovery location Tanks should be provided with permanent stairs or ladders and walkways with standard guardrails and toeboards Tanks should be emptied, cleaned, and inspected for structural weaknesses at regular intervals, and records kept of each inspection Tanks for holding volatile materials should be bonded and grounded, and provided with emergency venting devices Venting should be in accordance with provisions of the Flam mable and Combustible Liquids Code, NFPA Standard No 30 If tanks are inside buidings, vents should discharge outside the buiding at a location free from any ignition source Be sure to consider the effects of corrosion on venting devices for tanks that will contain corrosive liquids Connections for filling and emptying tanks are preferably made through the top to mini mize liquid loss and the possibility of injury from a broken fitting Fill lines should be plainly labeled and be equipped with a drain Use of compressed air is not permitted for the transfer of flammable or corrosive liquids, according to NFPA Standard No 30, para graph 8331 Cleaning tanks is an exceedingly dangerous operation An exact and specific procedure should be set up, preferably m written form, and strictly ahered to Specifications for tank-cleaning procedure are set forth m NFPA Standard No 327, and API publi cations RP 2015 (see "References") The procedure should be modified for toxic compounds only to the extent that more com plete protective equipment may be required Liquid aromatic mtro-compounds and amines are solvents for rubber and are absorbed through it gradually as well as through the skin For such exposures, personal protec tive equipment should be made of one of the inert synthetic rubbers or plastics (This in cludes gloves, aprons, boots, respiratory- and eye-protective equipment) The handling of phenolic compounds such as carbolic acid, cresylic acid, and the cresols requires precautions against skin absorption, although these compounds are not such effective rubber solvents as the nitro and amino compounds To prevent pumps from being pnmed with dangerous liquids where connection is made through the top of a tank, self-pnming pumps or pumps that generate enough suction to lift the liquid from the bottom of the tank should be used Pipelines for carrying chemicals are prefer ably installed in trenches or tunnels If they must be installed overhead, they should be isolated so that they will not dnp on men working underneath Pipelines for carrying fiammables should not be installed m tunnels There are three major sources of chemical injury m pipeline work Failure of packing in valve stems or OF GASKETS IN BOLTED FLANGES To mini mize injuries from valve packing failure, the valve stem can be surrounded by a sheet metal box or hood which will deflect spray away from the man operating the valve So far as possible, packing should be renewed without pressure on the valve Opening the wrong valve To prevent injuries and accidents from this source, pipe lines and valves should be identified by tags, lettered markings and distinctive colors (See the next section, "Identification of pip ing ") It is also desirable to have valves well separated and the immediate area well lighted to assure quick and easy identification Failure to assure that valves are CLOSED AND LOCKED AND THE LINES DRAINED BEFORE TENSION IS RELEASED ON FLANGE BOLTS The opening between the faces of the flange may be temporarily covered with a piece of sheet lead while the flange bolts are being loosened and the faces sepa rated The bolts farthest away should be loosened first so that drainage will tend to go away from the workman Blinds should be inserted in the flanges as soon as they are opened For lines which are opened often, blinds permanently pivoted on a flange bolt, one end acting as a gasket and the other as a blind, can be used At the conclusion of a job on a pipeline containing corrosive chemicals, tools and personal protective equipment should be thoroughly washed with a reagent which will 518