1. PURPOSE
1.1 This global engineering specification defines and describes the minimum requirements for the installation of heat shield systems for use on high-temperature piping, valves, and fittings.
2. scope
2.1 This specification covers the installation of heat shield systems for use on high-temperature piping, valves, and fittings to provide personnel protection, where it has been determined that heat shields are required in lieu of insulation.
2.2 This insulation material is identified on drawings with the symbol H3 (see 4WPI-INS015).
3. related documents
3.1 Air Products Engineering Documents 4WPI-INS015 Heat Shields for Personnel Protection – Material Symbol H
3.2 American Society for Testing and Materials (ASTM) B 209 Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate B 221 Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
3.3 All standards and documents referred to herein shall be the latest issue, unless otherwise stated.
4. DEFINITIONS
4.1 Air Products and Chemicals, Inc. and its subsidiary and associated companies will be referred to herein as Air Products.
4.2 The insulation contractor who supplies and installs the insulation will be referred to herein as the contractor.
4.3 Approved equal in this specification means “approved in writing by Air Products.”
4.4 All temperatures and dimensions in the text of this document are given in metric units with US customary units in parenthesis.
5. WAIVERS
5.1 Applications for waivers of the requirements contained in this specification shall be made in writing to the Air Products representative, who will obtain approval and written authorization from the relevant Air Products manager prior to order, supply, or installation by the contractor.
5.2 In order that any request by the contractor may be evaluated, the contractor shall submit complete and full details of the recommended alternative.
6. WARRANTY
6.1 The contractor shall provide a warranty guaranteeing the installation’s mechanical integrity against wind, weather, and normal operating conditions, and also the vapor barrier’s integrity against the ingress of moisture, all for a period after acceptance by Air Products of the insulation installation’s completion to be agreed in writing prior to start of installation.
7. MATERIALS
7.1 All materials and accessory materials to be used with this installation specification are defined in the heat shield system specification (see 4WPI-INS015).
7.2 The contractor shall supply all materials and accessory materials unless otherwise stated in the contract. The material shall be strictly according to the heat shield system specification, which provides full names and addresses of eligible suppliers.
8. MATERIAL REFERENCES
8.1 All materials are indicated in the text and figures of this specification by the numbers shown in square brackets, thus [0], that refer to the materials in Section 7, and are identified in the following list. [1] Standoff [2] Band [3] Guard [4] Clip [5] Fasteners [6] “U”-Nut [7] Fasteners
9. DETAILED FABRICATION AND INSTALLATION REQUIREMENTS
9.1 Details for installing heat shields on straight piping, elbows, tees, flanged joints, and valves are shown in Figures 1 through 6.
9.2 Standoffs [1] shall be installed first using a band [2]. The band shall be installed with standoffs is placed around the pipe, drawn tight, and secured with a band seal or a sheet metal screw fastened to a standoff. Standoffs shall be equally spaced around the circumference of the pipe or fitting. See Figure 1 and Table 1 for quantity and dimensions of standoffs required versus nominal pipe size.
9.3 Expanded metal guards [3] are prerolled to a radius equal to the outside radius of the pipe plus the height of the standoff (Dimension “B” in Figure 1). The guards shall be fastened to the standoffs using fasteners [5]. The number of sections required shall be the minimum number required to facilitate fabrication and ease of installation. All exposed edges of expanded metal shall have bond sheared edges or shall be covered with “U” edging crimped to the expanded metal.
9.4 Clips [4] shall be fabricated as required for elbows (Figure 3), flanges (Figure 5), and valves (Figure 6) to provide the necessary support and means of attachment for the guards [3].
9.5 Shields for elbows shall be constructed using clips [4] and segmented sections of expanded metal [3]. A minimum of four standoffs are required for elbows to provide attachment for the four clips—inside and outside radius plus top and bottom. The standoffs on adjoining straight pipe shall line up with those on the elbow (see Figure 3).
Note: Elbows require a minimum of four standoffs (see Figure 3).
9.6 Shields for tees shall be the same as for straight piping except that a cutout shall be made in the straight run to allow for the branch pipe (see Figure 4).
9.7 Shields for flanges shall be fabricated using prerolled expanded metal [3] with the radius being equal to the flange radius plus 50 mm (2 in.). The shield [3] shall be attached using clips [4] and fasteners [5]. The annular areas on both sides of the enlarged guard shall be covered with expanded metal [3] (see Figure 5).
9.8 Shields for valves shall be fabricated similar to flanges with the bottom half of the enlarged guard having a radius and the top half being constructed in a split box arrangement. The annular areas and box ends shall be covered with expanded metal [3]. Clips [4], “U”-nuts [6], and fasteners [5] and [7] shall be used to facilitate assembly (see Figure 6).
10. SITE ESTABLISHMENT AND PREPARATION
10.1 All heat shield installation shall be performed strictly according to this specification, the Insulation Summary, piping isometrics, and drawings provided by Air Products.
10.2 The contractor shall comply with all local and national regulations and safety rules.
10.3 The contractor shall comply with Air Products site and safety rules.
10.4 The contractor shall supply all material, tools, transport, and supervision required for satisfactory completion of the insulation contract.
10.5 All materials shall be new and shall be applied by competent personnel according to the manufacturer’s instructions, unless otherwise specified herein.
10.6 All materials and all installation of heat shields shall be available for inspection by Air Products. Material having defects shall be replaced, and any defects found in the installation shall be corrected by the contractor at their expense.
10.7 Before starting work on site, the contractor shall prepare and obtain the agreement of the Air Products representative regarding their detailed program for the work. They shall also obtain agreement for the site establishment and for the location of working areas.
10.8 All pressure testing shall be satisfactorily completed before application of any heat shield materials.
10.9 Heat shield and accessory materials shall only be applied to surfaces that are clean, dry, and frost-free, and when the ambient temperature is above +2°C (36°F). Great care shall be taken to prevent damage to the paint system, especially on stainless steel piping or equipment as this paint does not fully harden until it has reached the system’s operating temperature for the first time.
10.11 The contractor shall verify with the Air Products representative, before commencing work on a pipe system or item of equipment, that the system is ready for heat shield installation and shall also confirm the requirements for any special conditions such as cleanliness or internal purge.
10.12 The contractor shall cover all openings in the equipment to prevent the ingress of foreign materials.
10.13 Welding or drilling on equipment, piping, and structures is prohibited.
10.14 Cutting and fitting of any heat shielding at tie-ins, valve handwheels, steel gratings, steel work, conduit, cable tray, tubing, pipe supports, or other interference shall be considered part of the insulation contract.
10.15 Repair and/or replacement in kind of any existing heat shielding at tie-in points shall be considered as part of the insulation contract.
10.16 The contractor shall remove all waste or surplus material.
Table 1 Heat Shield Standoff Quantities and Dimensions
| Nominal | Dimensions | |||
| Pipe Size | Quantity | A | B | T |
| DN [in] | mm [in] | mm [in] | mm [in] | |
| 15 [1/2] | 3 | 15 [1/2] | 20 [3/4] | 3 [1/8] |
| 20 [3/4] | 3 | 15 [1/2] | 20 [3/4] | 3 [1/8] |
| 25 [1] | 3 | 15 [1/2] | 20 [3/4] | 3 [1/8] |
| 40 [1-½] | 3 | 15 [1/2] | 20 [3/4] | 3 [1/8] |
| 50 [2] | 3 | 15 [1/2] | 20 [3/4] | 3 [1/8] |
| 80 [3] | 3 | 25 [1] | 25 [1] | 3 [1/8] |
| 100 [4] | 3 | 25 [1] | 25 [1] | 3 [1/8] |
| 150 [6] | 3 | 50 [2] | 50 [2] | 3 [1/8] |
| 200 [8] | 3 | 50 [2] | 50 [2] | 3 [1/8] |
| 250 [10] | 3 | 50 [2] | 50 [2] | 3 [1/8] |
| 300 [12] | 4 | 50 [2] | 50 [2] | 3 [1/8] |
| 350 [14] | 4 | 50 [2] | 50 [2] | 3 [1/8] |
| 400 [16] | 4 | 50 [2] | 50 [2] | 3 [1/8] |
| 450 [18] | 5 | 50 [2] | 50 [2] | 3 [1/8] |
| 500 [20] | 5 | 50 [2] | 50 [2] | 3 [1/8] |
| 600 [24] | 6 | 50 [2] | 50 [2] | 3 [1/8] |
| 750 [30] | 7 | 50 [2] | 50 [2] | 3 [1/8] |
| 900 [36] | 8 | 50 [2] | 50 [2] | 3 [1/8] |
Figure 1 Heat Shield Standoff Dimensional Detail
Figure 2 Heat Shield Installation Detail Straight Piping
Figure 3 Heat Shield Installation Detail Typical Elbow
Note: Use a minimum of four standoffs on all elbows.
Figure 4 Heat Shield Installation Detail Typical Tee
Figure 5 Heat Shield Installation Detail Typical Flanged Joint
Figure 6 Heat Shield Installation Detail Typical Valve
Appendix a Installation Quality Assurance Report
| Contract Reference | Report No. |
Description of work inspected to Air Products Engineering Specification 4WPI-INS016
| Area Location | Description of Equipment | Line Number | Insulation System Applied |
| 1. | Pre-application inspection | Pipe/equipment ready for insulation | Yes/No |
| Erection and assembly complete | |||
| System successfully pressure tested | |||
| Painting complete, dry, and accepted | |||
| Surface clean and dry | |||
| 2. | Materials | Correct Materials supplied | |
| 3. | Heat shield | Stand-off properly spaced and banded | |
| Guard properly attached using fasteners | |||
| 4. | Finishing | Site cleaned and rubbish removed |
| Report by | Date |