Document 8R2rmr3qm1xNdREDVxLnX9XEm

DOUBLE LAYER SECTION 2 HI-TEMP APPLICATION Page 18 SEALING CRACKS (cont'd.) 4B7.3 Vessels exposed to the weather, during this period, shall be protected to keep the insulation dry until the finish is applied. 5 DOUBLE LAYER INSULATION 5A INNER LAYER - SQUARE EQUIPMENT 5A1 APPLICATION A1.1 If the 2 layers of insulation are of different thicknesses the one greater in thickness shall be used as the inner layer. For example; if 2^" thick insulation is specified, 1^" thick and 1" thick blocks shall be used. The lM thick shall be used as the inn*-'* `'ayer. 5A1.2 The inner layer of double layer* application shall be applied the same as single layer application on square equipment (see section 1 - paragraphs 5.A1 through 5A3.1) e^eot for the following: a) The insul-pins shall be long enough to penetrate both layers of insulation. The pins shall not be cut off until the outer layer has been applied. b) Flanged joint insulation shall overlap the inner layer equipment insulation on both sides of both vertical and horizontal vessel flanges. c) Flange insulation shall have a minimum thickness equal to the 2 layers of insulation specified for the equipment. 5B INNER LAYER - DUCTWORK 5B1 APPLICATION 5B1.1 If the 2 layers of insulation are of different thicknesses the one greater in thickness shall be used as the inner layer. For example; if 2-|" thick insulation is specified, 1^" thick blocks shall be used for the inner layer and 1" thick blocks for the outer layer.