Breathers

Storage. For receiving glycerol from standard 30.3-m (8000-gal) tank cars (36.3-t), a storage tank of 38—45-m ((10-12) x 10 — gal) capacity should be employed. Preferably it should be of stainless steel (304 or 316), of stainless- or nickel-clad steel, or of aluminum. Certain resin linings such as Lithcote have also been used. Glycerol does not seriously corrode steel tanks at room temperature but gradually absorbed moisture may have an effect. Therefore, tanks should be sealed with an air-breather trap. 

Venting ply + breather ply V Release fabric + bleeder ply Laminate... 

Explosion-proof enclosures are characterized by strong metal enclosures with special close-fitting access covers and breathers that contain an ignition to the inside of the enclosure. Field wiring in the hazardous environment is enclosed in a metal conduit of the mineral-insulated-cable type. All conduit and cable connections or cable terminations are threaded and explosion-proof. Conduit seals are put into the conduit or cable system at locations defined by the National Electric Code (Article 501) to prevent gas and vapor leakage and to prevent flames from passing from one part of the conduit system to the other. 

Fmisli The materials are the same as for pipe and should satisfy the same criteria. Breather springs may be required with bands. 

This test is prescribed by ANSI C-37/20C for isolated phase bus systems after they have been assembled at site. The test is conducted by filling the enclosure with air up to a pressure of 15 cm of water (1500 N/m ). After the air supply is shut off, the pressure must not drop to less than 7,5 cm of water in 15 seconds. All breathers and drain holes must be sealed before the test. 

The greatest source of contamination is extraneous matter. Atmospheric dirt, for example, is always a serious threat. It can enter the oil system through vents, breathers, and seals. Its primary effect is equipment wear, but plugging of oil lines and ports, and reduced oxidation stability of the oil are also serious effects. 

To prevent the accumulation of moisture in conduits and enclosures, drains should be installed at all low points. In classified areas, breathers and drains must be explosion-proof. Figure 17-28 shows typical explosion-proof breathers and drains. 

Figure 17-28. Standard explosion-proof drains and breathers. [Courtesy of Crouse-Hinds Elecfrica Construction Materials, a division of Cooper Industries, inc.)...

As noted in Section 5.3.6, if a flame arrester monnted on a breather vent nozzle of an atmospheric tank becomes plngged, overpressnre may occnr when the tank is filled or a vacnnm may occnr when the tank is emptied. Overpressnre or vacnnm may also be cansed by ambient temperatnre change. See Section 6.1 for additional information. 

Figure 7-9D. Protection against two different pressures from opposite directions using graphite disks, such as in ciosed storage tanks. Particularly API-type to guard against failure of primary breathers, conservation vents, etc. These require a differential of at least 10 psig between the two burst ratings, depending on diameters of disks. By pemnission. Continental Disc Corporation.

Figure 7-37A. Performance curve for conservation breather vent, dead weight type for vacuum, 8 inch size. By permission. The Protectoseal Co.

Combustion equipment, when first commissioned, can be set to operate at its optimum efficiency. With time, however, there will be a deterioration due to blockage of air filters and breather holes, wear in valve linkages, etc. Such changes may have safety implications if gas-rich firing is a consequence. 

Solid impurities must be continuously removed because hydraulic systems are self-contaminating due to wear of hoses, seals and metal parts. Efforts should be made to exclude all solid contaminants from the system altogether. Dirt is introduced with air, the amount of airborne impurities varying with the environment. The air breather must filter to at least the same degree as the oil filters. 

Inadequate or blocked scavenge oil passages Flats on races or rolling elements Loss of clearance Brinelling due to due to excessive assembly abuse, adapter tightening handing, or shock loads Clogged breather... 

In addition to the use of softer bearing materials for applications where abrasives may potentially be present, it is important to properly maintain filters and breathers, which should regularly be examined. In order to avoid oil supply contamination, foreign material that collects at the bottom of the bearing sump should be removed on a regular basis. 

Interestingly, the mouse is much more sensitive to HC1 than the rat [13-16]. In turn, however, the rat works as a good model for a primate, as far as lethality due to HC1 is concerned [17, 18]. This is important because all rodents (mice and rats) are obligate nose breathers, while primates can also breathe through their mouths, and it has been speculated that this would make rodents less sensitive to HC1 than primates [19]. 

Large storage tanks need a breather vent (technically called a conservation vent) to allow air to move into and out of the tank as a result of temperature and pressure changes and a change in the tank liquid level. Unfortunately, these vents also allow volatile materials to escape, resulting in potential worker exposures. 

Locate conduit to avoid moisture. Provide breathers and drains if necessary. The use of conduit seals within 18 inches of the detector is required to prevent the passage of moisture through the conduit and into the detector enclosure. If moisture is allowed to accumulate in the detector housing, premature detector failure can occur. 

Rats and mice are normally obligatory nose breathers. Note whether each animal is breathing through its mouth (if it is, place a check in the appropriate box). 

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