Congealing temperature

Congealing temperature (waxes) NFT 60-128 ISO 2207 ASTM D 938 Observation during cooling... 

The US. Pharmacopeia (USP) specification for phenol includes (/) purity is to be no less than 98 wt %, (2) clear solubiUty of 1 part of phenol in 15 parts of water, (2) a congealing temperature to be not lower than 39°C, and (4) a content of nonvolatiles of no more than 0.05 wt %. Commercially, phenol specifications far exceed the USP requirement. Typical commercial phenol specifications are Hsted in Table 5. Higher purity material is required for some apphcations. 

Characteristics Colourless to yellowish liquid or crystalline solid (congealing temperature app. 15 to 20°C, according to its E-anethole content). 

Characteristics Colourless to light yellow liquid or crystalline mass (congealing temperature 15-19°C). 

The congealing temperature of the blood serum of polar fish of Arctic or Antarctic regions (e. g. Trematomus borchgrevinski, Dissostichus maw-soni, Boreogadus saida) is about — 2 °C and thus is significantly lower than that of other fish (—0.6 to — 0.8 °C). Antifreeze gly-coproteins account for such low values. The amino acid sequence of this class of proteins is characterized by high periodicity ... 

Morrell and Egloff, The Congealing Temperature. .. of Cracked Residue, Ref. Nat. Gaso. Mfr. April, 1923, p. 17. 

Pour and Freezing Points. Congealing temperatures cannot be estimated with accuracy because none of the common methods of classifying materials such as Characterization Factor, Correlation Index, aniline... 

D87. Open or closed capillary tubes are used to measure the melting point of many of the natural waxes. The congealing point (ASTM D938) is the temperature at which a melted wax ceases to flow, and is more consistent than melting points for some waxes. 

Heat tracing of PR valve inlet piping should be provided where plugging by icing, deposition of wax or congealing of viscous liquids may occur at ambient temperatures. 

Fig. 4.11. Unexpected formation of a metastable phase of acetaminophen as a result of exposure to the molten wax formulation during spray-congeal processing. Note The three curves have been manually offset on the F-axis from the normal zero milliwatt baselines in order to display the relative X-axis (temperature) differences between the three samples.

Petroleum becomes more or less a plastic solid when cooled to sufficiently low temperatures. This is due to the congealing of the various hydrocarbons that constitute the oil. The cloud point of petroleum (or a product) is the temperature at which paraffin wax or other solidifiable compounds present in the oil appear as a haze when the oil is chilled under definitely prescribed conditions (ASTM D2500, D3117). As cooling is continued, petroleum becomes more solid, and the pour point is the lowest temperature at which the oil pours or flows under definitely prescribed conditions when it is chilled without disturbance at a standard rate (ASTM D97). 

If the oil or grease congeals or solidifies at ambient temperatures, the tank and/or skimmer will require heaters to maintain fluid flow. This is especially true at temperatures where water freezes. The use of rust inhibitors, high temperatures, and variable pH levels can affect the efficiency of oil skimmers. Turbulent waters may emulsify the water and oil and limit the system effectiveness. All information is from the vendor and has not been independently verified. 

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