| Reference Documents | |
| 28-3ES30600 | Materials for Oxidizer Service Application Guideline |
| 28-4WEQ6804 | Painting and Corrosion Protection for Operating Temperatures to 427°C (800°F) |
| 28-4WPIINS001 thru 28-4WPIINS030 | Various insulation specifications, sorted by type and temperature. |
| 28-660114 | Removable Insulation Covers (+100° to +1200°F) |
1. Preparation
1.1 Determine the types of insulation needed and if the proper specifications are on hand.
1.2 Determine scope of work by highlighting the insulated lines on a set of piping drawings. Report and clarify omissions, discrepancies, or other portions that seem unclear.
1.3 Develop a work list to order insulation areas needed to be worked on to assist with mechanical completion and overall schedule.
1.4 Verify that all materials ordered by the contractor are as per the specifications.
1.5 Before starting insulation, all supports and anchors need to be installed and pressure testing of the circuit needs to be complete.
1.6 Coordinate insulation details with the mechanical and instrument contractors for temporary spacers on pipe supports.
1.7 Keep the thickness of insulation in mind to prevent the contractor from running small-bore pipe, conduit, or supports too close to insulated lines.
1.8 Consider small lines containing water in dead ends that would require heat tracing and insulation. This also applies to instrument air signal tubing where air may be moist.
1.9 Coordinate with electrical contractor to assure heat tracing is in place prior to insulation and after pipe pressure testing.
1.10 Note if corrosion protection under insulation is necessary per applicable specification, usually for Rockwool, calcium silicate, or fiberglass. Corrosion protection must be installed prior to beginning that insulation.
2. Insulation types
2.1 Calcium silicate / Mineral Wool
2.2 Insulation symbols F, M, N, T, V, X and Y.
2.3 See specifications 28-4WPIINS009 thru 28-4WPIINS014, 28-4WPIINS019 and 28-4WPIINS020.
3. PIR
3.1 Insulation symbol P
3.2 See specification 28-4WPIINS006 thru 28-4WPIINS008.
4. Cellular Glass
4.1 Insulation symbol C and D.
4.2 See specification 28-4WPIINS001 thru 28-4WPIINS005.
5. Starting Insulating
5.1 The surrounding temperature must be above 35° F before insulation work can begin.
5.2 The surfaces to be insulated must be clean and free of debris.
5.3 Before insulating, verify that all check valves are installed in the proper flow direction. All check valve’s locations and flow directions need to be clearly marked on the outside of the insulation jacket.
5.4 Check the insulation termination plates used. Welding at the pipe and plate may cause plate warping and proper installation procedures shall be used to prevent warping. The insulation system at the termination plate needs to be properly sealed.
5.5 Insulation supports shall not be welded on to vessels in the field.
6. Insulating smooth surfaces
6.1 All internal insulation layers must be snug fitting with the surface and each layer, no void space is allowed. Note that pipe and tube outside diameter sizes are different and can result in insulation being erroneously interchanged.
6.2 Inside and outside seams need to be staggered. With the joints interspaced as far apart as possible between adjacent layers.
6.3 On horizontal runs of pipe, insulation should not be installed with the upper layer’s longitudinal seam located vertically (12:00 o’clock). Longitudinal seams should be at 9:00 o’clock and 3:00 o’clock.
6.4 Make sure the proper numbers of expansion joints are used on straight runs.
6.5 Verify the proper spacing of support plates are used in vertical runs.
6.6 Consider support spacing on all cryogenic lines to avoid possible cracking of insulation due to unsupported lengths, especially with cellular glass.
6.7 Where branches are mitered, miter inside-to-inside and then outside-to-outside.
7. Insulating valves and fittings
7.1 Fittings require single layer, full thickness, fabricated with tongue and groove longitudinal seams, and a recess for the inside layer on circumferential seams.
7.2 Some flanges, fittings, and other pieces do not get insulated, depending on the insulation and item. Refer to the specifications or the project engineer if you have questions.
7.3 All air pockets in mastic/fiberglass fittings should be cut, patched, and redone. All cavities should be filled with mastic.
7.4 Make sure all voids around valves or other odd shapes are either packed with insulation or injected with foam urethane.
7.5 Extended stems of cryogenic valves must be insulated in accordance with insulation specification details.
8. Oxygen piping concerns
8.1 Cellular glass must be used on all areas where exposure to leaked oxygen is possible.
8.2 This includes valves, flanges, threaded items, and other mechanical connections.
8.3 The area encompasses 4’ around the possible leak point both horizontally and above, and 10’ below.
9. Adjacent insulation needs a minimum clearance of 2’-6” or must be cellular glass.
9.1 The proper, oxygen compatible cement needs to be used during insulation installation. Asphaltic and bitumen-based materials are forbidden.
9.2 Materials other than what is specified must be approved by mechanical design group.
9.3 Oxygen vents or drains cannot discharge onto non-cellular glass insulation.
10. Finishing up
10.1 Make sure all insulation has the appropriate outer covering as specified. External coatings could be mastic, foil-backed paper, PVC covers, and corrugated metal covers among others. External seams shall be located as defined by specification and installation details.
10.2 Make sure that the sharp edges on straps on metal coverings are tucked under or trimmed back so as not to create a safety hazard.
10.3 Removable covers or jackets are to have permanent labels or tags affixed to them, indicating fabricator and item being covered.
10.4 Make sure that heat traced insulated lines are marked on the outside at 10’ intervals.
10.5 Insulation must be inspected immediately after start-up to check for ice spots, condensation, noise, and other indicators of poor quality insulation installation.
11.QC DOCUMENTATION
11.1 Written approval for any material substitutions.
11.2 Approval of fabricator, model number, and material for all removable covers and jackets.