13. Supports, Anchors and Seals in HVAC Installation
13.1 Pipe Hangers and Supports
13.1.1 Hangers: Pipe sizes ½ ” to 1½” shall be adjustable wrought steel ring.
13.1.2 Hangers: Pipe sizes 2” and over shall be adjustable wrought steel clevis.
13.1.3 Multiple or Trapeze Hangers shall be steel channels with welded spacers and hanger rods, cast iron roll and stand for pipe sizes 6 inches and over.
13.1.4 Wall Support shall be welded steel bracket, hanger rod and wrought steel clevis.
13.1.5 Vertical Supports shall be steel riser clamp.
13.1.6 Floor support for cold pipe sizes shall be cast iron adjustable pipe saddle, locknut nipple, floor flange and concrete pier to steel support.
13.1.7 Hangers shall be designed to impede disengagement by movement of supported pipe.
13.1.8 Copper plated hangers and supports shall be provided for copper piping or sheet lead packing provided between hanger or support and piping.
13.1.9 Galvanized hangers and supports shall be provided for galvanized pipe.
13.1.10 Galvanized steel saddles shall be provided for insulated pipes between insulation and hanger. Saddles shall be minimum 20 gauge, 305 mm long and half circumference.
13.2 Pipe Anchors
Anchors shall be sufficiently rigid to transmit load effects into their foundation. Anchors for expansion loops shall be designed to withstand the end reactions of the line due to thermal expansion or contraction, plus friction loads and surge loads.
13.3 Hanger Rods
Steel hanger rods shall be threaded both ends, threaded one end, or continuous threaded.
13.4 Duct Hangers and Supports
13.4.1 Hangers shall be galvanized steel band iron or rolled angle and 9.53 mm rods.
13.4.2 Wall supports shall be galvanized steel band iron or fabricated angle bracket.
13.4.3 Vertical supports at floor shall be rolled angle.
13.5 Sleeves
13.5.1 Pipes through beams, walls, fire proofing, footings, potentially wet floors shall be formed with steel pipe or 18 gauge galvanized steel.
13.5.2 Round ducts shall be formed with galvanized steel.
13.5.3 Rectangular ducts shall be formed with galvanized steel.
13.5.4 Sleeves shall be large enough to allow for movement due to expansion and to provide for continuous insulation.
13.6 Execution
13.6.1 Supports shall be attached only to main structural framing members and concrete slab. Where supports are required between main structural framing members, suitable intermediate metal framing shall be provided.
13.6.2 Pipe Hangers and Supports shall be as per Table VII
Table VII – Pipe Hangers and Support
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- Hangers shall be installed to provide minimum 13 mm clear space between finished covering and adjacent work.
- Hangers shall be located within 305 mm of each horizontal elbow.
- Hangers that are a vertically adjustable 38 mm minimum shall be used after piping is erected.
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13.6.3 Duct hangers and supports, static pressure in duct less than 500 Pag and velocities less than 10 m/s:
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- Hanger Minimum Sizes:
(i) Up to 760 mm wide: 25 mm x 16 gauge at 3.0 m spacing.
(ii) 761 mm to 1220 mm wide: 38 mm x 16 gauge at 3.0 m spacing. (iii) Over 1220 mm wide: 38 mm x 16 gauge at 2.5 m spacing.
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- Horizontal Duct on Wall Supports Minimum Sizes:
(i) Up to 455 mm wide: 38 mm x 16 gauge or 25 mm x 25 mm x 3.0 mm at 2.5 m spacing.
(ii) 456 mm to 1020 mm wide: 38 mm x 38 mm x 3.2 mm at 1.25 m spacing.
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- c. Vertical Duct on Wall Supports Minimum Sizes:
(i) Up to 630 mm wide: 38 mm x 16 gauge at 3.65 m spacing.
(ii) 631 mm to 915 mm wide: 25 mm x 25 mm x 3.2 mm at 3.65 m spacing. (iii) 916 mm to 1.2 m wide: 32 mm x 32 mm x 3.2 mm at 3.65 m spacing.
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- Vertical Duct Floor Supports Minimum Sizes:
(i) Supports shall be riveted or screwed to duct. (ii) Up to 1.5 m wide: 38 mm x 38 mm x 3.2 mm (iii) Over 1.5 m wide: 51 mm x 3.2 mm
13.6.4 Duct Hangers and Supports, Static pressure in duct up through 1.5 kPag and velocities greater than 10 m/s:
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- Rectangular Duct Hangers Minimum Sizes:
(i) Up to 915 mm wide: 2 at 25 mm x 16 gauge at 3.0 m spacing.
(ii) 916 mm to 1.5 m wide: 2 at 25 mm x 16 gauge at 2.4 m spacing with 51 mm x 51 mm x 6.3 mm trapeze.
(iii) 1.51 m to 3.0 m wide: 2 at 38 mm x 12 gauge at 2.4 m spacing with 51 mm x 51mm x 6.3 mm trapeze.
(iv)3.01 m to 6.1 m wide: 3 at 9.5 mm diameter at 1.2 m spacing with 63.5 mm x 63.5 mm x 4.7 mm trapeze.
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- Round Duct Hangers Minimum Sizes:
(i) Up to 460 mm diameter: 25 mm x 16 gauge at 3.0 m spacing.
(ii) 461 mm to 915 mm diameter: 25 mm x 12 gage at 3.0 m spacing.
(iii) 916 mm to 1270 mm diameter: 38 mm x 12 gauge at 3.0 m spacing.
(iv)1271 mm diameter and above: 2 at 38 mm x 12 gauge for girth reinforcing angle at 3.0 m spacing.
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- Vertical Duct Floor Supports Minimum Sizes:
(i) Supports shall be riveted to duct and angles tied together with rod, angles or cinch band.
(ii) Up to 1.2 m wide: 38 mm x 38 mm x 3.2 mm. (iii) Over 1.2 m wide: 51mm x 51mm x 4.7 mm.
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- Angle reinforcing may be used for support omitting trapeze.
13.6.5 Equipment Bases and Supports:
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- Anchor bolts shall be provided for major HVAC equipment.
- Supports shall be constructed of structural steel members or steel pipe and fittings. Supports shall be braced and fastened with flanges bolted to structure.
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- Rigid anchors shall be provided for ducts and pipes immediately after vibration connections to equipment.
13.6.6 Exposed steel hangers and supports shall be prime coated. Hangers and supports located in crawl spaces, pipe shafts and suspended ceiling spaces shall not be considered exposed.
13.6.7 Sleeves:
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- Sleeves shall be set in position in advance of concrete work. Suitable reinforcing around sleeves shall be provided.
- Sleeves shall be extended through potentially wet floors 25 mm above finished floor level. Sleeves shall be caulked full depth and floor plate shall be provided.
- Piping or ductwork passing through floor, ceiling, wall, space between pipe or duct and construction shall be closed off with non-combustible insulation. Tight fitting metal caps shall be provided on both sides and be caulked.
- Chrome plated escutcheons shall be installed where piping passes through finished surfaces.
- Penetration through fire rated wall or roof shall be sealed off with a HILTI fire stop system.