Material Incompatibility

Data can also be gathered experimentally on the compatibility of materials. Incompatibility charts have been published by the U.S. Coast Guard (1994), ASTM (1980) as well as others. See Frurip (Frurip et ah, 1997) for a description of experimental tests and published compatibility charts. 

A link between the material used and the geometry of the component is compounded in the formulation for the tolerance to process risk as shown in equation 2.3. It is recognized that increasing material incompatibility and geometry complexity... 

Accelerated corrosion and loss of containment due to material incompatibility... 

CORROSION - Recommended materials - Prohibited materials INCOMPATIBLE WITH - Water - Heat transfer fluids - Metals - Plastic materials, others... ... 

Within the working part of the vacuum system the use of all-metal valves is not common indeed, since the advent of PTFE taps there are few occasions when such taps are necessary. Nevertheless, it is worthwhile to note that suitable taps do exist for operations involving materials incompatible with both PTFE and grease, or if a good static vacuum (see Section 2.3.1) is required for a long time in circumstances where a glass tap would be inappropriate. 

NOx. Can react vigorously with reducing materials. Incompatible with, (NH4CI + heat), (C + heat), organic matter, P, NaOCl, NaC104. Occasional explosions in presence of oil, (NH4)2S04 with K or Na. 

Combustible when exposed to heat or flame can react vigorously with oxidizing materials. Incompatible with I2, pyridine, SO3. When heated to decomposition it emits toxic fumes of NOx. Has exploded while in storage. 

DOT CLASSIFICATION 4.3 Label Dangerous When Wet, Poison SAFETY PROFILE Human poison by ingestion causing nausea, vomiting, death. Flammable when exposed to heat or flame. This material is stable while kept dry. In moist air, it decomposes slowly. Reacts violently with acids or acid fumes to emit the highly toxic and flammable phosphine. Violent reaction with concentrated sulfuric acid, nitric acid, and oxidizing materials. Incompatible with HCl, H2SO4. When heated to decomposition it emits toxic fumes of POx and ZnO. Used as an acute rodenticide. See also PHOSPHIDES and... 

Materials incompatibility is one of the most frequent causes of process incidents. Degradation of seals and gaskets that have become softened by solvent effects can lead to minor leaks or major loss of containment, and hence to fires, explosions, or more serious accidents. If seal or gasket leakage is identified in a process, then the plant engineer should consult with the manufacturer to confirm the material is suitable for the service. If necessary, all the seals or gaskets of that material should be replaced with something more resilient to the process conditions. 

Containment sound design of equipment and piping, to avoid leaks. For example, specifying welded joints in preference to gasketed flanged joints that are liable to leak or suffer materials incompatibility problems. 

List the materials incompatibility problems you should be aware of in plants that handle... 

Even with the best and most expensive fittings rated for hydrogen use, you can encounter problems with severe weather such as arctic conditions or desert conditions, or extremely wet conditions and/or any seasonal or daily changes - anything that creates stress or shows materials incompatibility in rates of expansion and contraction. 

BARIUM DINITRATE (10022-31-8) BaN20j A strong oxidizer accelerates the burning of combustible materials. Incompatible with reducing agents, including hydrides, nitrides, sulfides, phosphorus, stannous chloride combustibles, strong... 

---