Freeze protection

The layout should ensure that exhausts are not placed close to fresh air intakes and that fire sprinkler protection for present and future requirements, eg, under stairs, storage racks, overhangs, covered walks, etc, is available. AH facility equipment must be stmcturaHy secured as well as freeze protected. 

Besides freeze protection, antifreezes provide many other performance properties that enhance the operation of a heat-transfer system. Because the internal combustion engine is by far the largest antifreeze appHcation, and ethylene glycol is the predorninant antifreeze in use, the following focus on the performance properties of an ethylene glycol-based antifreeze and their relationship to engine cooling. 

Low ambient tern- Monitor temperature perature resulting. adequate heating in embrittlement and/or mechanical design system to accommodate minimum failure of reactor. expected temperature Provide freeze protection/heat tracing CCPS G-23 CCPS G-29 Lees 1996... 

Extensiv e freezing protection is required for the whole scrubber system in cold climates. 

Where larger, semibulk quantities of sulfite-based oxygen scavengers are required, a 20 to 25% bisulfite solution is recommended. It is sufficiently concentrated to provide reasonable freeze protection. The overall oxygen scavenging reaction is ... 

Freeze protection is not normally provided in separators intended solely for emergency release service however, occasionally, coils or a... 

Many of these enclosures are designed to meet certain standards. For example, the American Society of Sanitary Engineers (ASSE) has developed Standard 1060, Performance Requirements for Outdoor Enclosures for Backflow Prevention Assemblies. If an enclosure will be used to house a backflow preventer, this standard specifies the acceptable construction materials for the enclosure, as well as the performance requirements that the enclosure should meet, including specifications for freeze protection, drainage, air inlets, access for maintenance, and hinge requirements. ASSE 1060 also states that the enclosure should be lockable to enhance security. 

Concentrations higher than 68% are not recommended 68% provides maximum freezing protection to approximately —92°F ( — 69°C). 

Ethylene glycol base coolants meeting specification requirements of ASTM D 3306, used at 50% concentration, offer freezing protection to —34°F (—37°C), provide a sufficiently high... 

Solutions of sugar or honey have also been tried. These are unsatisfactory because high concentrations are required to provide adequate freezing protection. These solutions are unstable as well as too viscous. 

After inspection and completion of required service, determine capacity of the cooling system from a cooling system protection chart or car owner s manual. A 50% concentration (—34°F [—37°C] freezing protection) is generally recommended. 

Recent surveys have shown that over-concentration and under-concentration are common sources of cooling system problems. A minimum concentration of 33 1/3% is required to provide minimal corrosion protection. Maximum freeze protection is obtained at 68% by volume. Concentrations over 68% will adversely affect heat transfer, raise freezing point, and may cause inhibitors to precipitate from the coolant when the engine is operating. 

Check Accuracy of Tester. Test the instrument with solutions of known freezing protection. A 33% solution of ethylene glycol engine coolant in water protects to 0°F (—18°C) and a 50% solution should indicate —34°F (—37°C) protection. 

Car manufacturers recommend that the factory-fill coolant be used for one to two years. Previous surveys [7] on the performance of coolants in automotive service indicated that about one third showed appreciable loss of freezing protection, loss of inhibitor reserve, and rust in solution at the end of one year. Before two full years, most coolants require change. Based on these data, major engine coolant manufacturers recommend that their products be used for one year, preferably changing each Spring or Fall. 

Table 6.4 Concrete with freeze-protection admixture (Ratinov and Rosenburg).

Property Plain concrete Freeze-protection admixture... 

Check that freeze protection systems are installed. 

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