ICAA Insulator flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Asbestos PEL for construction

0.1 fiber per cubic centimeter as an 8-hour TWA under OSHA 29 CFR 1926.1101; Class I thermal system insulation removal also requires a negative-pressure enclosure, decontamination unit, and competent person.

Fall protection trigger height

OSHA construction rules require fall protection at 6 feet (1.8 m) above a lower level under 29 CFR 1926.501; the general-industry trigger under 29 CFR 1910.28 is 4 feet.

Silica action level

25 micrograms per cubic meter as an 8-hour time-weighted average, with a permissible exposure limit of 50 micrograms per cubic meter under OSHA 29 CFR 1926.1153.

Respirator fit test interval

Fit testing is repeated annually and whenever a different respirator model, style, or size is used; a medical evaluation is required before fit testing under 29 CFR 1910.134.

k-value definition

Thermal conductivity in Btu-in per hour-square foot-degree Fahrenheit: heat flow through one inch of material per square foot per degree of temperature difference. R-value equals thickness divided by k.

ASTM E84 indices

Surface burning test reporting flame spread index and smoke developed index; many insulation specifications require a flame spread of 25 or less and smoke developed of 450 or less.

Cellular glass properties

Closed-cell, noncombustible, and essentially impermeable to water vapor, so no separate vapor retarder is needed; it is brittle, strong in compression, and must be chloride-free on stainless steel.

Chloride stress corrosion cracking

Austenitic stainless steel under insulation can crack when leachable chlorides concentrate at the surface; ASTM C795 sets acceptance limits and ASTM C871 is the leachable-chloride test method.

Pipe insulation seam location

Longitudinal joints are rotated off the top of the pipe to the side or bottom, so the seam is not a water-collection point and is not visible from the floor.

Staggered double-layer joints

When two insulation layers are required, the outer layer joints are offset from the inner layer joints so no straight-through path exists for heat flow or moisture migration.

Contact adhesive technique

Apply adhesive to both mating surfaces, let the solvent flash until tacky, then join and press firmly; a wet bond traps solvent and produces a weak joint that later opens.

Effect of compression

Compressing fibrous insulation reduces installed thickness and R-value; pieces are cut slightly long and fitted without forcing so joints stay tight along the run.

Hanger insert purpose

High-density insulation inserts or blocks at pipe hangers carry the load, prevent crushing of the insulation, and preserve thermal performance at each support point.

NFPA 90A duct limits

Duct insulation and coverings must have a flame spread index of 25 or less and a smoke developed index of 50 or less when tested in accordance with ASTM E84.

Removable insulation blankets

Fabricated pads with lacing hooks and straps that cover valves, flanges, and strainers so the component stays insulated but can be opened for service and reused.

Insulating expansion loops

Loops and offsets use oversized sections, slip joints, or extra clearance so pipe movement is absorbed without tearing the insulation or opening the vapor retarder joints.

Perm rating scale

One perm equals one grain of water vapor per hour per square foot per inch of mercury; materials rated 0.1 perm or less are Class I vapor retarders.

ASJ jacket

All-service jacket is a factory-applied foil-scrim-kraft laminate with permeance near 0.02 perm or less; every joint, lap, staple, and puncture must be sealed.

Metal jacket lap direction

Laps are at least 2 inches and are installed upper over lower like shingles so water runs off; stainless bands secure the jacket about 12 inches on center.

PVC jacketing temperature limit

PVC jacketing is typically limited to about 150 F service; CPVC or metal jacketing is used at higher temperatures or where UV and impact resistance are needed.

Division 23 07 13

The MasterFormat section number for HVAC duct insulation, covering insulation materials, thicknesses, vapor retarders, facings, and installation requirements.

Purpose of submittals

Product data, shop drawings, ASTM test reports, and samples submitted for designer approval before installation; installing unapproved material is at the contractor's risk.

RFI definition

A Request for Information is a formal written question to the designer used to resolve drawing conflicts, missing details, or ambiguous specifications before work proceeds.

Drawing revision block

A block on each sheet listing revision number, date, and description; layout and fabrication are performed only from the current issued revision.

Banding tool use

Tensions stainless steel bands around jacketing and crimps a seal; bands are typically spaced about 12 inches on center and set back from jacket ends.

Gore count on elbows

Segmented 90-degree elbows are commonly fabricated from 3, 4, or 5 gores; more gores give a smoother curve and less wrinkling on large diameters.

Serrated insulation knife

A long serrated blade cuts fibrous insulation with minimal compression; a sawing motion against a straightedge produces square cuts and tight-fitting joints.

Insulation storage requirements

Keep insulation indoors, off the floor, and in original wrapping until installation; wet fibrous insulation loses R-value and laminated facings can delaminate.

Labor unit definition

Installed craft hours required per unit of material, such as per linear foot of pipe or per fitting; multiplied by quantity to give total estimated hours.

Waste factor

A percentage added to the takeoff for cutting loss and damage, commonly 5 to 10 percent for pipe insulation and 10 to 15 percent for fittings.

Installed thickness check

Verify thickness with a thin probe or gauge at random locations; compressed, thin, or missing sections reduce R-value and fail the specification requirement.

As-built drawings

Marked-up drawings recording actual installed routing, sizes, and quantities; they support final payment, change-order substantiation, and future maintenance work.