Valves gaskets

To achieve the more detailed improvements suggested here, it may be necessaiy to add a few questions to those asked during a norm HAZOP. For example, what types of valves, gaskets, and so forth, will be used ... 

An ethylene compressor was shut down for maintenance and correctly isolated by slip-plates. When repairs were complete, the slip-plates were removed before the machine was tried out. During the tryout, some ethylene leaked through the closed isolation valves into the machine. The ethylene/air mixture was ignited, either by a hot spot in the machine or by copper acetylide on the copper valve gaskets. The compressor was severely damaged. 

Make sure gaskets do not, even partly, obstruct the inlet or outlet passage as when opening the valve, (gasket) pieces may be tom off and cause leakage. Obstructions in the oudet passage may cause excessive backpressure. 

McKinnery (USA) 1992 Removal and installation of valve gaskets and packing Asbestos Airborne fiber concentrations (fibers/m structuies/m )... 

McKinnery, W. N., Jr., and Moore, R. W. (1992). Evaluation of airborne asbestos fiber levels during removal and installation of valve gaskets and packing. Am Ind Hyg Assoc 53, 531-532. 

SE-. [GE Silicones] Silicone rubber compds. for conq)r., transfer, and inj. molding, extrusion, calendering, o-tings, cylinder lino seals, hydraulic seals, valve gaskets, tubing, belting, shock mounts, tolls, closed cell qxxige, coated fabrics. 

Check periodically for leaks from sources such as pump packings, valves, gasketed covers, sight glasses, pipe joints, and so forth. 

MAJOR APPLICATIONS Poly(p-phenylene sulfide) (PPS) is mainly used in the reinforced form with glass fiber or mineral fillers as a high-performance thermoplastic. It is used for electrical and electronic parts (e.g., plugs and multipoint connectors, bobbins, relays, switches, encapsulation of electronic component, etc.), automobile parts (air intake systems, pumps, valves, gaskets, components for exhaust gas recirculation systems, etc.), and as components for mechanical and precision engineering. Nonfiller PPS is used for fiber, film, sheet, nonwoven fabric, etc. 

Caution There are chances of fire due to the circulating high-temperature oil, and hence, the motors, electrical fittings, and lighting must be flameproof. The pipelines, valves, gaskets, and pumps (with mechanical shaft seals) must he selected for high-temperature and high-pressure service and shall he tested as per statutory requirements. 

Caution Since the system works on circulating high-temperature oil, it does present a fire hazard and hence all relevant precautions must be taken for example, motors, electrical fittings, lighting must be flameproof. Besides, the pipelines, valves, gaskets, shaft seals, etc. must be suitable for high temperature and pressure and should be tested and certified. 

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