27 Insulation of valves and flanges Heat loss incurred through non insulated

27 insulation of valves and flanges heat loss

This preview shows page 43 - 45 out of 191 pages.

1.2.7 Insulation of valves and flanges Heat loss incurred through non insulated fixtures such as valves and flanges are substantial, even at low temperatures. An uninsulated valve located outside loses as much heat at 250 °F (120 °C) as 100 ft (30.5 m) of uninsulated piping. The temperature of the medium can also decrease to such an extent at non-insulated fittings or flanges, that process critical temperatures are reached, at which point for example, the medium will start to crystallize. Valves and flanges should therefore be insulated as much as possible. To avoid damage during inspection or repairs, the insulation for valves and flanges is designed with removable coverings or hoods, to allow rapid disassembly. Removable coverings or hoods are usually insulated from the inside with wired mats or flexible ProRox ® insulation (FSL Series). The coverings are fastened to the object with lever fastenings, which are fixed directly onto the covering or on to straps. Take the following conditions into account when designing insulated coverings for fittings and flanges: The overlap distance of the insulated covering over the insulated pipe should be at least 2" (50 mm). The pipe insulation should end at the flanges, leaving a gap equal to the bolt length +1.2" (30 mm) and should be closed off with a lock washer so the flange can be loosened without damaging the insulation. With valves, an extended spindle should preferably be fitted horizontally or below the pipe to prevent leakage along the spindle shaft. The cladding must be fitted to prevent the ingress of moisture in the insulation. On inclined or vertical piping, for example, mount rain deflectors above the removable coverings. If the ingress of moisture into the insulation is unavoidable, make 0.4" (10 mm). diameter drain holes in the removable covering. 1.2 Insulation of piping 1. Pipe - 2. ProRox ® insulation - 3.  Cladding - 4. Sheet-metal screw or Rivet - 5. Swage - 6. Drainage opening - 7. Strap - B ≥ 2" (50 mm) - A = bolt length + 1.2" (30 mm) 1. Pipe - 2. ProRox ® insulation - 3.  Cladding - 4. Sheet- metal screw or rivet - 5. Rain deflector - 6. Lock washer - 7. Straps - 8. Rain deflector - B ≥ 2" (50 mm) - A = bolt length + 1.2" (30 mm) 2" (50 mm) 5 0.8" (20 mm) A number of possible design options for insulation systems for pipe fittings and flanges follow: 40
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Insulation of piping Leakages With pipes where a leaking fluid content could damage the insulation or the coating system in the removable covering, mount flange straps with a leak detection fitting around the flange. Flange bands can also prevent flammable products from penetrating into the insulation material and can help prevent the outbreak of fire. 1. Pipe - 2. ProRox ® insulation - 3. Cladding - 4. Sheet- metal screw or rivet - 5. Swage - 6. Drainage opening - 7. Straps – B ≥ 2" (50 mm) - A = Bolt length + 1.2" (30 mm) 1. Pipe - 2. Insulation: ProRox ® Pipe Sections - 3. Cladding - 4. Sheet-metal screw or rivet - 5. Removable coverings (insulated from the inside) - 6. Swage 2" (50 mm) 0.8" (20 mm) 1. Pipe - 2. ProRox ® insulation - 3. Sheet - 4. Sheet-metal screw or rivet - 5. Rain deflector - 6. Lock washer - 7. Straps - 8. Lock washer -
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