ASTM C945-05(2023)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C945 − 05 (Reapproved 2023)
Standard Practice for
Design Considerations and Spray Application of a Rigid
Cellular Polyurethane Insulation System on Outdoor Service
Vessels
This standard is issued under the fixed designation C945; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D2200 Practice for Use of Pictorial Surface Preparation
Standards and Guides for Painting Steel Surfaces
1.1 This practice concerns itself with the substrate prepara-
2.2 American National Standards:
tion and priming, the selection of the rigid cellular polyure-
Z87.1 Practice for Occupational and Educational Eye and
thane system, and the protective insulation coatings for outdoor
Face Protection
service equipment.
2.3 Clemtex Limited Standard:
NOTE 1—For the purpose of this practice, polyurethane is defined to
“Anchor Pattern Standard”
mean either polyurethane or polyisocyanurate and is hereafter referred to
as “PUR/PIR.”
2.4 National Association of Corrosion Engineers Standard:
TM-01-70 Visual Surface Preparation Panels
1.2 The values given in inch-pound are to be regarded as the
2.5 Other Documents:
standard. The values given in parentheses are for information
Safety Precautions in Handling and Spraying of PUR/PIR
only.
6,7
Systems
1.3 This standard may involve hazardous materials,
operations, and equipment. This standard does not purport to
3. Terminology
address all of the safety concerns, if any, associated with its
3.1 Definitions—Definitions included in Terminology C168,
use. It is the responsibility of the user of this standard to
Definitions D883, and Abbreviations D1600 apply to the terms
establish appropriate safety, health, and environmental prac-
used in this standard.
tices and determine the applicability of regulatory limitations
3.2 Definitions of Terms Specific to This Standard:
prior to use.
3.2.1 blasting—the process of cleaning surfaces by use of
1.4 This international standard was developed in accor-
abrasive particles propelled at high velocity upon the surface to
dance with internationally recognized principles on standard-
be cleaned.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
3.2.2 coatings/coverings—ultraviolet ray-absorbing and
mendations issued by the World Trade Organization Technical
water-shedding protective materials applied over the urethane
Barriers to Trade (TBT) Committee.
foam.
3.2.3 density:
2. Referenced Documents
3.2.3.1 in-place density—the weight per unit volume of the
2.1 ASTM Standards:
cross section of foam from substrate to exposed surface,
C168 Terminology Relating to Thermal Insulation
including all skins (or surfaces).
D883 Terminology Relating to Plastics
3.2.3.2 core density—the weight per unit volume of a single
D1600 Terminology for Abbreviated Terms Relating to Plas-
layer of foam excluding top and bottom skins or (if present)
tics
interlayer skins.
This practice is under the jurisdiction of ASTM Committee C16 on Thermal
Insulation and is the direct responsibility of Subcommittee C16.40 on Insulation Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
Systems. 4th Floor, New York, NY 10036, http://www.ansi.org.
Current edition approved March 1, 2023. Published March 2023. Originally Available from Clemtex Ltd., P.O. Box 15214, Houston, TX 77020.
approved in 1981. Last previous edition approved in 2017 as C945 – 05 (2017). Available from NACE International (NACE), 1440 South Creek Dr., Houston,
DOI: 10.1520/C0945-05R23. TX 77084-4906, http://www.nace.org.
2 6
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Spray Polyurethane Foam Alliance (SPFA), 4400 Fair Lakes Ct, Suite 105,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Fairfax, VA, http://sprayfoam.org
Standards volume information, refer to the standard’s Document Summary page on Alliance for the Polyurethane Industry (API), 1300 Wilson Blvd Suite 800,
the ASTM website. Arlington, VA 22209, http://polyurethanes.org
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C945 − 05 (2023)
3.2.4 foam system—appropriate formulations of two liquid 5.1.3 Galvanized Metal Surfaces—Clean with an acceptable
components, polyisocyanate, or A side, and polyol, or B side, solvent, wash with water to remove deposits, spray with an
for intended applications. acceptable wash primer, and then coat all areas with an
acceptable primer or coating.
3.2.5 ignition barrier—cement plaster or equivalent
coating/covering providing a resistance to ignition of the foam
NOTE 3—This procedure is not always required depending on the age of
the metal, exposure, and use.
insulation acceptable to the concerned building or fire
department(s), or both. (Designated UL test is optional.)
5.1.4 Aluminum Surfaces—Degrease with appropriate sol-
vents. Coat the clean, dry surface with a recommended primer
4. Significance and Use
or coating.
4.1 This practice facilitates the selection and application of 5.1.5 Stainless Steel Surfaces—Degrease with appropriate
an insulation system for use at service temperatures be- solvents. Coat the clean, dry surface with a recommended
tween − 30 and + 107°C (−22 and + 225°F). Although the primer or coating. (Chloride-free materials are recommended
successful installation of spray-applied PUR/PIR is influenced on surfaces operating above 140°F (60°C).)
by many factors, this practice treats those four areas found to
be of major importance:
6. Recommended Blasting Procedures
(1) Substrate preparation,
6.1 All surfaces to be primed or coated shall be prepared to
(2) Substrate priming,
the degree of cleanliness and surface profile as recommended
(3) Insulation application, and
by the primer supplier. Pictorial D2200 shall be used as the
(4) Protective coatings.
standard. Blast-cleaned surface acceptance will be by one or
4.2 Abrasive blasting, primer application, spray application more of the following visual comparison methods:“ Anchor
of the insulation, and protective coating application each Pattern Standards” NACE Visual Surface Preparation Panels
contribute their unique health and safety hazards to the job site (Standard TM-01-70), and Pictorial D2200.
and will be dealt with in more detail under their respective
6.2 All welding, burning, etc., shall be completed prior to
headings.
the blasting operation.
5. Substrate Preparation 6.3 Remove any grease or oil with a petroleum solvent or
water-detergent solution. All flux, spatter, slag, or other lami-
5.1 Proper substrate preparation is mandatory to obtain a
nations left from welding must be chipped or ground off.
successful foam application. These preparation methods must
Rough welds and other sharp projections should be ground
remove any contaminants that will interfere with development
smooth by the fabricator prior to the blasting operation.
of the maximum adhesion of the urethane foam. The method(s)
chosen are dependent upon the contaminants present on the 6.4 Sandblast sand shall be sharp, graded flint or silica sand
surface and the end-use design service temperature. (16 to 30 mesh). Where inorganic zinc coatings are applied, the
surface preparation shall be abrasive blasted using 16 to
5.1.1 Previously Coated Iron and Steel Surfaces—The ad-
30-mesh sand, G40 to 50 grit, or an equivalent abrasive that
hesion of spray-applied urethane to previously coated surfaces
will provide a similar surface profile. All abrasives shall be free
is directly influenced by the age, type, and condition of the
of all dust, dirt, and other foreign matter. They shall be kept dry
surface. For this reason any coating that exhibits chalking,
and free of oil at all times.
peeling, or other evidence of failure or damage must be
removed and an appropriate primer applied. Abrasive blasting
MANDATORY HEALTH AND SAFETY
is recommended. If blasting is to be accomplished, all items
PRECAUTIONS FOR BLASTING OPERATIONS
listed under Section 6 should be followed. In all cases, the
6.4.1 Effective oil and water traps shall be used to ensure
coated substrate must be cleaned and free of rust, grease, oil,
clean, dry air supply to the abrasive pot. Water shall be
dirt, dust, moisture, etc., immediately prior to foam spraying by
continuously bled from the moisture trap.
one or more of the following methods: (a) wash with water and
6.4.2 A “dead-man” valve shall be used on all blast nozzles.
allow to dry, (b) brush, (c) broom, or (d) air blast.
6.4.3 All blast hoses shall have an antistatic lining.
5.1.2 New Iron or Steel Surfaces—Field blasting and prim-
ing is recommended. All blasting is to be accomplished in 6.4.4 All blast nozzles shall be properly grounded.
accordance with items listed in Section 6. Shop preparation is
6.4.5 Nozzle blast operators exposed to blasting dust shall
also acceptable with proper field surface preparation of the
wear a U.S. Bureau of Mines-approved helmet connected to a
weld joints and all damaged areas. In all cases, the substrate to
clean, breathable compressed air source.
be sprayed with foam shall be free of rust, grease, oil, loose
6.4.6 All others exposed to blasting dust shall wear a U.S.
particles, and mill scale, moisture, dirt, etc. After priming is
Bureau of Mines-approved filter-type respirator. Adequate
complete, all areas that are specified to be insulated shall be
personnel protection from flying particles shall be provided in
washed with water and allowed to dry, brushed, broomed, or
any blasting operation.
air-blasted prior to applying the insulation.
6.4.7 If at any time the blasting equipment and material
specifications are not being met, the owner may suspend the
NOTE 2—Caution: Be sure the primer is useable at the design tempera-
ture and acceptable under the foam insulation. operation.
C945 − 05 (2023)
6.4.8 Blasted surfaces shall not be allowed to become wet or 7.2.9 All flames, sparks, welding, and smoking shall be
dulled by oxidation to a point where visible rusting has prohibited in the application area.
occurred.
7.2.10 All affected items, in the surrounding area, shall be
6.4.9 All surfaces shall be primed during the same day that protected from overspray.
they are blasted.
7.2.11 Spray guns must be held perpendicular to the surface
6.4.10 Surface cleanliness and profile depth shall be suitable
being painted and adjusted so that dry overspray is minimized.
for the metal primer to be used. These conditions shall be
monitored in accordance with the visual comparison methods
8. Selection of the Foam System
specified herein.
8.1 A wide range of foam systems is available in various
6.4.11 Surfaces inspected and found to not meet the criteria
densities, each exhibiting different temperature limitations,
outlined in 6.1 – 6.4 must be blasted again.
combustibility characteristics, etc. The use of these systems in
combination with each other or with conventional insulation
7. Selection of Metal Primer
products offer a broad range of economical installations.
7.1 The following items shall be considered when choosing
8.2 Published properties are usually determined on
a metal primer:
laboratory-produced samples. The thickness of foam sprayed,
7.1.1 Surface preparation required,
number of passes, temperature of the substrate, ambient
7.1.2 Foam adhesion, substrate adhesion, and heat resis-
temperatures, etc., have a pronounced effect on all properties.
tance at the maximum and minimum vessel operating
8.3 Resistance to chemical attack from in-service exposure
temperatures, and
shall be considered in the selection of the proper foam system.
7.1.3 Corrosion resistance to spilled vessel contents.
The degree of possible damage to the foam system is deter-
7.2 Listed below are general application recommendations,
mined by the amount of the chemical, its type, temperature,
which may vary depending on the type of primer selected:
and duration of contact.
7.2.1 The manufacturer’s recommendations for thinning,
8.4 Listed below are several items that shall be considered
mixing, handling, and applying his products shall be consid-
in the selection of the foam system:
ered a part of this practice.
8.4.1 Insulation temperature limitation versus vessel oper-
7.2.2 All bolts, welds, faying surfaces, sharp edges, and
ating design temperature,
difficult access areas shall receive a primer spot-coat prior to
8.4.2 Dimensional stability under simulated service
primer spray application.
conditions,
7.2.3 The primer shall be applied in a fashion to obtain
complete coverage. 8.4.3 Combustibility characteristics,
7.2.4 Primer shall not be applied during rain, snow, fog, 8.4.4 Application conditions (substrate and ambient
mist, high relative humidity, or low metal temperatures. The temperatures, etc.),
relative humidity and dew point shall be determined at the job 8.4.5 History of similar application or laboratory data relat-
site using a surface thermometer and wet/dry bulb sling
ing to the application in question,
psychrometer.
8.4.6 Compressive strength,
7.2.4.1 Priming of the metal shall not be permitted when the
8.4.7 Adhesion to substrate, and
temperature of the metal is at or below the dew point or above
8.4.8 Thermal re
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