Danger line

TABLE 13-1 Distances a Guard Must Be from a Danger Line for Various Sizes of Openings... 

Distance of Opening from the Danger Line (in.) Maximum Width of Opening (in.)... 

Figure 13-4. The danger line for in-running rolls is where the rolls are 3/8 in apart. The danger line determines the pinch point. The distance from the 3/8 in pinch point becomes the reference for guard placement.

A point-of-operation guard will be installed on a machine with a feed table. An operator will feed material into the machine. The material will be 1 1/8 in. thick and require a 1/8 in. clearance in an opening in the guard. How far must the guard be from the danger line ... 

All clamps holding glass apparatus should be lined with cork, attached by means of glue or seccotine , or with asbestos paper this will reduce the danger of fracture if excessive pressure is exerted on the clamp. 

Personnel Hazards The following case history illustrates how vacuum can be harmful and dangerous to personnel. A plant superintendent was checkiug an open nozzle on a glass-lined reactor on which there was a vacuum pump pulling vacuum, when suddenly his arm was sucked into the nozzle, up to his shoulder. He could not remove his arm until help arrived to release the vacuum on the vessel. He was injured painfully, though not seriously. The injury could have been veiy serious if help had not been nearby. Personnel hazards can also result from vacuum conveyor systems for solids handling. 

Special resins consist of a two-phase system composed of a mix of a highly condensed, and no longer soluble, PF-resin with a standard type PF-resin [63]. Another two-phase resin is composed of a highly condensed PF-resin, still in an aqueous solution, and of a PF dispersion [64]. The purpose of such special resins is the gluing of wet wood, where the danger of overpenetration of the resin into the wood surface exists and would cause a starved glue line. 

In addition to the formation of scale or corrosion of metal within boilers, auxiliary equipment is also susceptible to similar damage. Attempts to prevent scale formation within a boiler can lead to makeup line deposits if the treatment chemicals are improperly ehosen. Thus, the addition of normal phosphates to an unsoftened feed water ean eause a dangerous eondition by elogging the makeup line with preeipitated calcium phosphate. Deposits in the form of calcium or magnesium stearate deposits, otherwise known as "bathtub ring" can be readily seen, and are caused by the eombination of ealcium or magnesium with negative ions of soap stearates. 

There are other sorts of dead-ends besides pipes that have been blanked. Rarely used valved branehes are just as dangerous. The feed line to a furnaee (Figure 9-1) was provided with a permanent steam connection for use during de-coking. 

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