Underground applications

Since tests with lethal emissions on humans are not possible, accidental human deaths have always been an invaluable, alternative source of information for toxicologists. Parts of underground mines can often become totally enclosed just like gas chambers from the inevitable accidents, especially roof failures, which often occur there. Gasoline engines have generally been outlawed for underground applications because of their notorious, toxic exhaust, but the history of Diesels underground is quite different. 

V Professional user risks resulting from direct exposure during product use and including occupational exposures not occurring in industrial facilities (e.g., outdoor or underground applications). 

Hazardous Gases Underground Applications to Tunnel Engineering... 

In recent years, continuous zinc ribbon anodes have been used in a variety of underground applications (Kurr, 1973 Peabody, 1976 O Connell, 1977). This type of product has broadened the applications for zinc anodes, for it provides small increments of current continuously along the entire length of a cathode. Its uses are generally considered to lie in specialty applications, where other methods of cathodic protection are either impractical or extremely costly (see later section on induced ac on pipelines). Bagnulo (1973, 1984) has developed a tape with an electrically conducting adhesive as described in the Mechanical Coatings part of Chapter 1. 

Standard Test Method for Laboratory Evaluation of Magnesium Sacrificial Anode Test Specimens for Underground Applications... 

Destruction by rodents is mainly a problem for underground applications. The Federal German Post Office spends some 200,000 Euros annually to repair rodent damage to cables and lines, caused by mice, hamsters, and rats. Typically, rodents gnaw at an installation depth of 60 cm. Behavioral research has established that plastics are destroyed by rodents without being used as food or to sharpen their teeth. The flakes and cuttings are not even used to build nests. 

Corrugated tubing also can serve in underground applications when soil support is given to flexible walls. 

Flexibility and toughness Most thermoplastic piping materials are flexible, which is an important characteristic for underground applications. The pipe can follow natural contours and transitions around obstacles, which reduces the number of fittings required in most piping applications. Because of their excellent flexibility characteristics, plastic piping materials woik well in harsh climate conditions. 

The polyether-based TPU of the 16N Series are used when extremely good hydrolysis and microbial resistance are required, e.g., in underground applications, such as certain cables. These polyether products comply with FDA regulations. 

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