- PURPOSE
1.1 This fabrication and erection specification defines the minimum requirements for insulation support and clip details for heat exchangers and pressure vessels that operate above ambient temperature.
2. scope
2.1 This specification applies to the design, fabrication, and installation requirements for insulation supports and clips on heat exchangers and pressure vessels that are external to cold boxes and that have an operating temperature between +21° and +750°C (+41° and +1382°F). It applies to all of the following insulation materials:
- Preformed cellular glass (450 x 650 mm or 18 x 26 inch blocks)
- Polyisocyanurate (1800 x 600 mm or 70 x 24 inch slabs)
- Mineral wool (1200 x 600 mm or 48 x 24 inch slabs)
2.2 The equipment supplier shall furnish all materials and labor associated with the design, fabrication, and installation of the insulation supports in accordance with this specification. All materials, bolts, and nuts are included in the scope of supply.
2.3 Unless the purchase documents state otherwise, insulation material is excluded from the scope of supply. The purchase documents will specify the type of insulation material to be used.
3. related documents
None
4. DESIGN AND CONSTRUCTION
4.1 Support bars shall be cut to clear nozzles, legs, and other appurtenances. Additional clips shall be provided at each end of the cut bars.
4.2 All vertical vessels with less than standard spacing between the tangent lines shall have a top and a bottom insulation support.
4.3 External shell stiffeners may be used as insulation supports.
4.4 Nuts and support clips welded to the shell shall be of the same nominal composition as the shell and shall be furnished with the material certification as required by the pressure vessel design and fabrication code. The support ring material shall be carbon steel.
4.5 Each welding operator and the welding procedure used to attach the nuts and support clips shall be approved in accordance with the pressure vessel design and fabrication code.
4.6 The following Table 1 specifies the required vessel support spacing (see Figure 1) for various operating temperature ranges:
Table 1
Required Vessel Support Spacing
|
Operating Temperature |
Support Spacing, “A”
for Insulation Material |
|||||
| °C | °F | Mineral Wool “A”, mm (in) | Polyisocyanurate “A”, mm (in) | Cellular Glass “A”, mm (in) | ||
| < 150 | < 302 | 5 400 | (210) | 5 400 (210) | 5 400 (210) | |
| 151–400 | 303–752 | 3 600 | (140) | 5 400 (210) | 5 400 (210) | |
| 401–550 | 753–1022 | 2 700 | (105) | 5 400 (210) | 5 400 (210) | |
| 551–750 | 1023–1382 | 1 800 | (70) | 5 400 (210) | 5 400 (210) | |
- The supplier shall provide ring/vessel supports (see Figure 1) dimensioned in accordance with Table 2M (metric units) or Table 2US (US common units).
Table 2M
Ring Vessel Supports, Metric Units
Insulation
Thickness mm |
Size of SupportBar and Clip Mm |
Dimensions | Hole Diameter | ||
| “B” mm | “C” mm | “D” Mm | Bolt Size | ||
| 25 | 15 x 8 | 9 | 9 | 7 | M6 |
| 38 | 20 x 8 | 12 | 12 | 7 | M6 |
| 50 | 30 x 8 | 20 | 20 | 10 | M8 |
| 63 | 40 x 8 | 25 | 25 | 10 | M8 |
| 75 | 55 x 8 | 28 | 35 | 12 | M10 |
| 88 | 70 x 8 | 35 | 40 | 14 | M12 |
| 100 | 75 x 8 | 38 | 50 | 14 | M12 |
| 112 | 90 x 8 | 45 | 56 | 14 | M12 |
| 125 | 90 x 8 | 45 | 65 | 14 | M12 |
| 138 | 105 x 8 | 55 | 70 | 14 | M12 |
Table 2US
Ring/Vessel Supports, US Common Units
Insulation
Thickness Inch |
Size of SupportBar and Clip Inch |
Dimensions | Hole Diameter “D” | Bolt Size
UNC |
||
| “B” Inch | “C” Inch | |||||
| 1 | 5/8 | x 5/16 | 3/8 | 3/8 | 5/16 | 1/4 |
| 1 1/2 | 3/4 | x 5/16 | 1/2 | 1/2 | 5/16 | 1/4 |
| 2 | 1 3/16 | x 5/16 | 3/4 | 3/4 | 3/8 | 5/16 |
| 2 1/2 | 1 9/16 | x 5/16 | 1 | 1 | 3/8 | 5/16 |
| 3 | 2 5/32 | x 5/16 | 1 1/8 | 1 3/8 | 7/16 | 3/8 |
| 3 1/2 | 2 3/4 | x 5/16 | 1 3/8 | 1 9/16 | 9/16 | 1/2 |
| 4 | 3 | x 5/16 | 1 1/2 | 2 | 9/16 | 1/2 |
| 4 1/2 | 3 1/2 | x 5/16 | 1 3/4 | 2 3/16 | 9/16 | 1/2 |
| 5 | 3 1/2 | x 5/16 | 1 3/4 | 2 9/16 | 9/16 | 1/2 |
| 5 1/2 | 4 1/8 | x 5/16 | 2 3/16 | 2 3/4 | 9/16 | 1/2 |
4.8 The following Table 3 specifies the required number of vessel support clips (see Figure 1):
Table 3
Required Number of Vessel Support Clips
| Number of Clips | ||
| Diameter of Vessel | End | Intermediate |
| <1200 mm (<47.3 in) | 2 | 2 |
| 1 201–2 000 mm (47.4–78.7 in) | 3 | 3 |
| 2 001–2 500 mm (78.8–98.4 in) | 4 | 4 |
| 2 501–3 000 mm (98.5–118 in) | 5 | 5 |
| 3 001–3 500 mm (118.1–137.7 in) | 6 | 6 |
| 3 501–4 500 mm (137.8–177.1 in) | 7 | 7 |
| 4 501–5 000 mm (177.2–196.9 in) | 8 | 8 |
4.9 Insulation supports on the bottom head of a vertical vessel shall be in accordance with Figure 2 and the following Table 4:
Table 4
Supports on Bottom Head of Vertical Vessel
| Insulation | Dimension | |
| Material | “E” | “F” |
Cellular Glass |
600 mm (24 in) | 450 mm (17.7 in) |
Mineral Wool |
600 mm (24 in) | 600 mm (24 in) |
Polyisocyanurate |
600 mm (24 in) | 600 mm (24 in) |
4.10 The insulation supports shall be fabricated and installed on the vessel and shall be shipped in‑place.
Note: Horizontal vessels do not require insulation supports or clips.
- CHANGE LOG
| Rev. | Date | Subject Matter Expert | Description of Revision |
| 0 | Sept. 2000 | Stephen Gibbon | New document |
Figure 1
Insulation Supports on Vertical Vessels
Figure 2
Position of Fixings on Bottom Head of Vertical Vessels
