Gas corrosion

Mrowec S and Werber T 1978 Gas Corrosion of Metals (Washington, DC National Bureau of Standards) Rapp R A (ed) 1983 High Temperature Corrosion—NACE 6 (Flouston, TX NACE)... 

Heat resistance and gas corrosion resistance depends on chemical, phase compositions and stmcture of an alloy. The local corrosion destmction (LCD) of heat resisting alloys (HRS), especially a cast condition, probably, is determined by sweat of alloying elements. 

Thermal fatigue characteristically results from temperature cycles in service. Even if an alloy is con ectly selected and operated within normal design limits for creep strength and hot-gas corrosion resistance, it can fail from thermal fatigue. 

Several steps can be taken to maximize the run time for the reciprocating compressor. Since wear is a function of rubbing speed, the piston speed can be kept to a minimum. Chapter 3 made recommendations for piston speed. Reliability problems due to valves are reputed to account tor 40% of the maintenance cost of the compressor. Valves are the single largest cause for unplanned shutdowns. Basically, valve life can he increased by keeping the speed of the compressor as low as practical. At 360 rpm, the valves are operated six times a second. At 1,200 rpm, ihc valves operate 20 times a second or 1,728,000 times in a day. It is not difficult to understand why the valves are considered critical. To keep the reliability in mind, valve type, material selection and application considerations such as volume ratio, gas corrosiveness, and gas cleanliness need attention by the experts. One final note is that while lubrication is an asset to the rubbing parts, it is not necessarily good for valve reliability. 

Nature of gas corrosion, entrained solid particles, entrained fibers, and entrained moisture. 

OPERATING CONDITIONS,EACH COMPRESSOR (Stondord Conditions 14.7psio and60 F.) Type of Gas Corrosive ... 

Reverse Flow Fall in line press, (compressor fails) high pressure at reactor NH3 in compressor — explosion hazard fit non-return valve (NRV1) hot wet acid gas-corrosion fit second valve (NRV4)... 

Some bromine compounds are covered specifically under Hazardous Materials Regulations. Other compounds may usually be shipped under the classification of chemicals, not otherwise indexed by name, without special requirements unless from their nature they would fall under a category such as combustible liquid, compressed gas, corrosive liquid (or solid), disinfectant liquid (or solid), dmg, dye intermediate (liquid), fire extinguisher, flammable gas (liquid or solid), insecticide, medicine, oxidizer or oxidizing material, poisonous liquid (gas or solid), solvent, or tear gas. Specific provisions apply to each of these categories and appropriate packaging and labeling are required. 

Macdonald DD, Cragnolino GA. Corrosion of steam cycle material. In Cohen P, ed. The ASME handbook on Water Technology for Thermal Power System. New York The American Chemical Society of Mechanical Engineers, 1989 653-1031. 

Sulphur dioxide, when dry, has no action on iron, even at 100° C., but the metal is slightly attacked by the moist gas.7 Liquid sulphur dioxide has likewise but little action under atmospheric pressure, but in refrigerators, where the temperature is liable to rise somewhat during compression of the gas, corrosion of the iron is appreciable. 

DOT CLASSIFICATION 8 Label Corrosive (UN 1789) DOT Class 2.3 Label Poison Gas, Corrosive (UN 1050, UN 2186) SAFETY PROFILE A human poison by an unspecified route. Mildly toxic to humans by inhaladon. Moderately toxic experimentally by ingestion. A corrosive irritant to the skin, eyes, and mucous membranes. Mutation data reported. An experimental teratogen. A concentration of 35 ppm causes irritation of the throat after short exposure. In general, hydrochloric acid causes little trouble in industry other than from accidental splashes and burns. It is a common air contaminant and is heavily used in industry. 

DOT CLASSIFICATION 2.2 Label Nonflammable Gas, Corrosive SAFETY PROFILE Corrosive to skin, eyes, and materials. When heated to decomposition it emits very toxic fumes of F" and CL. See also FLUORIDES and CHLORIDES. 

Hot gas corrosion behavior of various silicon-based non-oxide ceramic materials (e.g., silicon carbide, silicon nitride, etc.) can vary widely depending on the stoichiometry, structure and sintering aids. Silicon carbide materials exhibit excellent corrosion resistance towards sulfur-containing atmospheres even at a high temperature around 1,400X [Fdrthmann and Naoumidis, 1990]. 

Fdrthmann, R., and A. Naoumidis, 1990, Influence of hot gas corrosion on the bending strength of silicon carbide materials, in High Temperature Corrosion of Technical Ceramics (R J. Fordham, Ed.), Elsevier Applied Science, London, U.K., p. 217. 

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