Water application-specific testing

The corrosion behavior tends to follow much the same pattern in clean sea water the world over. If there is pollution, it may cause an unbalance of the pH, change the marine organism concentration, decrease the dissolved oxygen, or alter the ionic balance of sea water. Pollution normally results in saline waters becoming considerably more aggressive to one or more metals. Specific tests must be made to determine the applicability of a metal in each type of polluted water. Sulfides, which are often found m such waters, tend to promote corrosion of both ferrous and nonferrous metals. 

Other Cresol-type Disinfectants and Antiseptics. Various non-irritant germicides of low toxicity, and therefore particularly suitable for disinfecting the skin and for application to wounds, contain different amounts of chloroxylenol, dichloroxylenol, benzyl cresols, o-phenylphenol, chloro-benzylphenols, special narrow-range boiling fractions of coal tar distillates, etc. They are usually dissolved in a soap, such as castor oil soap, and essential oil solution as they are only sparingly soluble in water. The various phenol coefficient tests, and particularly the Chick-Martin test, are of value in standardising such preparations, but they are of little value in determining their practical efficacy as antiseptics. For such purposes, other more specific tests are required which are beyond the scope of this book. 

D-3110 (see wood adhesive specifications), tests for strength retained after exposure and sets forth minimum performance criteria. Exposures include atmospheric water soak, vacuum-pressure water soak, boiling, and exposure to elevated temperatures in an oven. Whenever dealing with adhesives falling in the categories covered by D-3110, durability should certainly be tested that way. However, these procedures almost certainly have other useful wood adhesive testing applications too. 

Special Arrester Types and Alternatives Several types of unlisted arresters (water seals, packed beds, velocity-type devices, and fast-acting valves) mentioned in API 2028 are described more fully in Howard (1982). There are few design or test data for hydraulic and packed-bed arresters some types are designed and used by indiviciual companies for specific applications, while others are commercially available. Figure 26-27 shows some special arrester types. 

The rate of product to be applied is the critical factor affecting all residue studies. The rate should be the highest recommended rate for that particular crop and should be applied at the limit of the GAP for the specific crop. The test item should ideally be pre-weighed in a laboratory prior to making the application. In most cases, this procedure results in easier accountability of test items, more accurate measurement of required doses, and more accurate application in the field since only the correct amount of water is required to be added by the field operator. This procedure also reduces the quantity of test item required and hence reduces the waste, which has to be disposed of. An additional spare sample, which is weighed at the same time in case of mishap with the original sample may be prepared. 

Although the relationship of PBT with water sounds complicated (and it is), PBT and its various blends have been used successfully for over 25 years in many different applications. In general, the hydrolysis of PBT is not a major concern. In some specific applications, however, it is critical. In all cases where PBT will see extensive moisture above its Tg, part testing under realistic water exposure conditions is needed to ensure adequate performance. 

ISO 12092 2000 Fittings, valves and other piping system components made of unplasticized poly(vinyl chloride) (PVC-U), chlorinated poly(vinyl chloride) (PVC-C), acrylonitrile-butadiene-styrene (ABS) and acrylonitrile-styrene-acrylester (ASA) for pipes underpressure - Resistance to internal pressure - Test method ISO 15493 2003 Plastics piping systems for industrial applications - Acrylonitrile-butadiene-styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) - Specifications for components and the system - Metric series ISO 15877-1 2003 Plastics piping systems for hot and cold water installations - Chlorinated poly (vinyl chloride) (PVC-C) - Part 1 General... 

ISO 23711 2003 Elastomeric seals - Requirements for materials for pipe joint seals used in water and drainage applications - Thermoplastic elastomers ISO 14910-1 1997 Plastics - Thermoplastic polyester/ester and polyether/ester elastomers for moulding and extrusion - Part 1 Designation system and basis for specifications ISO 14910-2 1997 Plastics - Thermoplastic polyester/ester and polyether/ester elastomers for moulding and extrusion - Part 2 Preparation of test specimens and determination of properties... 

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