Selective plugging, definition

Tube Pitch and Layout. The selection of tube pitch (see Fig. 17.6 for the definition) is a compromise between a close pitch for increased shellside heat transfer and surface compactness, and an open pitch for decreased shellside plugging and ease in shellside cleaning. In most shell-and-tube exchangers, the ratio between tube pitch and outside diameter ratio varies from 1.25 to 2.00. The recommended ligament width depends upon the tube diameter and pitch the values are provided by TEMA [5] the minimum value is 3.18 mm (1/8 in) for clean services and 6.35 mm (1/4 in) where mechanical cleaning is required. 

First off, you can apply compression (or limiting where the Amount slider is set to 50 1) to four individual bands two on the first page of the plug-in and two on the other. You can use one or all four, but you ll definitely want to work one band at a time by selecting the Solo option on the band you are modifying. Bands are activated by un-checking the Band bypass option at the bottom of the dialog box. 

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