6.2.1  Construction materials

 

The construction materials may be conveniently divided into those used in contact with the steam, and those used in contact with the cooling water. Generally, plate materials, hollows and bars comply with BS4360: 1972 [9] and BS1501: 1964 [10].

Details of materials for components, such as condenser tubes and tubeplates which are in contact with the cooling water, are thoroughly discussed in Section 4 of this chapter. In addition, an interface clearly exists between selection of tube material and structural design. It is important, therefore, to select these materials early in the design stage in order that tube support arrangements and the effects on structural stiffness may be finalised.

On conventional power stations, condensing plant components which are in contact with steam are normally constructed from either ferrous or non-ferrous materials. Recent specifications for a Pressurised Water Reactor (PWR) power station have indicated that non-ferrous metals should not be used, since the build-up of deposits from corrosion/erosion effects associated with non-ferrous materials, could be passed through the feedheating plant, and jeopardise the inverted tube bundle of the steam generator. The steam generator, unlike conventional boilers, has much greater restrictions on the frequency of blowdown operations.

 

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