ASTM C585-90(2004)

Standard Practice for Inner and Outer Diameters of Rigid Thermal Insulation for Nominal Sizes of Pipe and Tubing (NPS System)

SIGNIFICANCE AND USE
The purpose of this practice is to ensure satisfactory fit on standard sizes, to accommodate radial expansion of pipes and tubes which are heated after being insulated, and to minimize the number of insulation sizes and thicknesses to be manufactured and stocked.
While insulation may be manufactured to these recommended dimensions, care should be exercised in attempting to nest layers of different materials, or layers supplied by different manufacturers. Individual manufacturing processes may operate at slightly different tolerances. While the product will fit the pipe, it may not readily nest as the outer layer between the different materials or with different manufacturers. Care should be exercised to determine these differences before specifying or ordering nesting sizes.  
Dimensions in accordance with this practice permit application of one thickness of pipe insulation over another (Nesting or Simplified Dimensional System), to obtain total thicknesses greater than those manufactured as single layer, or for multilayer application when desired.
SCOPE
1.1 This practice is intended as a dimensional standard for preformed rigid thermal insulation for pipes and tubing.
1.2 This practice covers insulation supplied in cylindrical sections, usually split into half-sections, and lists recommended inner and outer diameters of insulation having nominal wall thicknesses from 1 to 5 in. (25 to 127 mm) to fit over standard sizes of pipe and tubing.
1.3 The values stated in inch-pound units are to be regarded as the standard. The values stated in SI units are provided for information only.
This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Mar-2004
• ICS: 27.220 - Heat recovery. Thermal insulation
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.20 - Homogeneous Inorganic Thermal Insulations

Relations

• Replaces: ASTM C585-90(1998) - Standard Practice for Inner and Outer Diameters of Rigid Thermal Insulation for Nominal Sizes of Pipe and Tubing (NPS System)
• Effective Date: 01-Apr-2004
• Replaced By: ASTM C585-09 - Standard Practice for Inner and Outer Diameters of Thermal Insulation for Nominal Sizes of Pipe and Tubing
• Effective Date: 01-Apr-2009
• Referred By: ASTM C1676/C1676M-23 - Standard Specification for Microporous Thermal Insulation
• Effective Date: 01-Apr-2004
• Referred By: ASTM C680-23 - Standard Practice for Estimate of the Heat Gain or Loss and the Surface Temperatures of Insulated Flat, Cylindrical, and Spherical Systems by Use of Computer Programs
• Effective Date: 01-Apr-2004
• Referred By: ASTM C1126-19 - Standard Specification for Faced or Unfaced Rigid Cellular Phenolic Thermal Insulation
• Effective Date: 01-Apr-2004
• Referred By: ASTM C591-22 - Standard Specification for Unfaced Preformed Rigid Cellular Polyisocyanurate Thermal Insulation
• Effective Date: 01-Apr-2004
• Referred By: ASTM C1710-22 - Standard Guide for Installation of Flexible Closed Cell Preformed Insulation in Tube and Sheet Form
• Effective Date: 01-Apr-2004
• Referred By: ASTM C534/C534M-23 - Standard Specification for Preformed Flexible Elastomeric Cellular Thermal Insulation in Sheet and Tubular Form
• Effective Date: 01-Apr-2004
• Referred By: ASTM C1767-21 - Standard Specification for Stainless Steel Jacketing for Insulation
• Effective Date: 01-Apr-2004
• Referred By: ASTM C547-22a - Standard Specification for Mineral Fiber Pipe Insulation
• Effective Date: 01-Apr-2004
• Referred By: ASTM C1729M-21 - Standard Specification for Aluminum Jacketing for Insulation
• Effective Date: 01-Apr-2004
• Referred By: ASTM C610-17(2023) - Standard Specification for Molded Expanded Perlite Block and Pipe Thermal Insulation
• Effective Date: 01-Apr-2004
• Referred By: ASTM C1639-19 - Standard Specification for Fabrication Of Cellular Glass Pipe And Tubing Insulation
• Effective Date: 01-Apr-2004
• Referred By: ASTM C533-17(2023) - Standard Specification for Calcium Silicate Block and Pipe Thermal Insulation
• Effective Date: 01-Apr-2004
• Referred By: ASTM C1410-17(2023) - Standard Specification for Cellular Melamine Thermal and Sound-Absorbing Insulation
• Effective Date: 01-Apr-2004

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:C585–90 (Reapproved2004)
Standard Practice for
Inner and Outer Diameters of Rigid Thermal Insulation for
Nominal Sizes of Pipe and Tubing (NPS System)
This standard is issued under the fixed designation C 585; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope nest layers of different materials, or layers supplied by different
manufacturers. Individual manufacturing processes may oper-
1.1 This practice is intended as a dimensional standard for
ate at slightly different tolerances.While the product will fit the
preformed rigid thermal insulation for pipes and tubing.
pipe, it may not readily nest as the outer layer between the
1.2 This practice covers insulation supplied in cylindrical
different materials or with different manufacturers. Care should
sections, usually split into half-sections, and lists recom-
be exercised to determine these differences before specifying
mendedinnerandouterdiametersofinsulationhavingnominal
or ordering nesting sizes.
wall thicknesses from 1 to 5 in. (25 to 127 mm) to fit over
4.3 Dimensions in accordance with this practice permit
standard sizes of pipe and tubing.
application of one thickness of pipe insulation over another
1.3 The values stated in inch-pound units are to be regarded
(Nesting or Simplified Dimensional System), to obtain total
as the standard. The values stated in SI units are provided for
thicknesses greater than those manufactured as single layer, or
information only.
for multilayer application when desired.
1.4 This standard does not purport to address the safety
concerns, if any, associated with its use. It is the responsibility
5. Procedure
of the user of this standard to establish appropriate safety and
NOTE 1—Suggested tolerances are shown for information purposes
health practices and determine the applicability of regulatory
only.
limitations prior to use.
5.1 Measurement:
2. Referenced Documents
5.1.1 Measurement of inner and outer diameters shall be
2.1 ASTM Standards: made to the nearest ⁄32 in. (0.8 mm) using a steel tape or rule.
C 168 Terminology Relating to Thermal Insulation 5.1.1.1 Half Sections—The diameter reported for each half-
section shall be the average of six measurements taken at three
3. Terminology
locations including two near the ends and one near the center
3.1 Definitions—Definitions pertaining to insulation are de-
(see Fig. 1a and Fig. 2a). Three of the six readings shall be
fined in Terminology C 168. taken in the longitudinal plane of the flat, cut surface: the other
three shall each be twice a half-diameter in the longitudinal
4. Significance and Use
plane at right angles to that of the first three (see Fig. 1b and
4.1 The purpose of this practice is to ensure satisfactory fit
Fig. 2b).
on standard sizes, to accommodate radial expansion of pipes
5.1.1.2 Hinged Sections—The diameter reported for each
and tubes which are heated after being insulated, and to
hinged section shall be the average of four measurements taken
minimize the number of insulation sizes and thicknesses to be
at both ends of the section (two per end) (see Fig. 3). The two
manufactured and stocked.
measurements at each end shall be at right angles.
4.2 While insulation may be manufactured to these recom-
5.2 Recommended Inner Diameters:
mended dimensions, care should be exercised in attempting to
5.2.1 Inner diameters and suggested tolerances for nominal
sizes of insulation for pipe are shown in Table 1. Iron pipe in
sizes for 4 ⁄2 , 5, 7-in. (113, 125, 175-mm), and larger
This practice is under the jurisdiction of ASTM Committee C16 on Thermal
odd-numbered diameters is not standard, but insulation for
InsulationandisthedirectresponsibilityofSubcommitteeC16.20onHomogeneous
Inorganic Thermal Insulations. these is included for multi-layer purposes.
Current edition approved April 1, 2004. Published May 2004. Originally
5.2.2 Inner diameters and suggested tolerances for nominal
approved in 1966 to replace C 312 and C 521. Last previous edition approved in
sizes of tubing through 6 in. (150-mm) are shown in Table 2.
1998 as C 585 – 90 (1998).
5.3 Recommended Outer Diameters:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C585–90 (2004)
Fig. 1a Three Meaurement Locations
Fig. 1b Diameter and Half-Diameter Measurement Locations
FIG. 1 Inner Diameter Measurement
Fig. 2a Three Measurement Locations
Fig. 2b Diameter and Half-Diameter Measurement Locations
FIG. 2 Outer Diameter Measurement
5.3.1 Nominal outer diameters for nominal sizes of pipe are 6. Keywords
shown in Table 3 and Table 4 and tubing in Table 5 and Table
6.1 pipe thermal insulation diameter; pipe thermal insula-
6. It should be noted that these values for both pipe and tubing
tion dimension; pipe thermal insulation thickness; thermal
are identical with iron pipe outer diameters as shown in
insulation; thermal insulating materials-pipe; thermal insulat-
Columns2and3ofTable3andTable4.Table3,Table4,Table
ing materials-rigid; tubing thermal insulation thickness
5, and Table 6 are for nesting purposes only. When product is
to be nested, it shall be so stated on order.
5.3.2 Suggested maximum outer diameters for nominal
sizes of pipe are shown in Table 7 and Table 8 and tubing in
Table 9 and Table 10. Table 7, Table 8, Table 9, and Table 10
are for jacketing purposes only.
5.4 Approximate Insulation Wall Thickness:
5.4.1 For information purposes, the wall thicknesses of pipe
insulation obtained by subtracting inner diameters in Table 1
from corresponding outer diameters inTable 3 andTable 4, and
dividingtheresultsbytwo,areshowninTable11.Correspond-
ing values for tubing are shown in Table 12.
C585–90 (2004)
FIG. 3 Hinged Section Measurement Locations
TABLE 1 Inner Diameter of Insulation for Nominal Pipe Size (NPS)
Pipe Insulation
Tolerance
Nominal Size Outer Diameter Inner Diameter
Minus Plus
in. in. mm in. mm in. mm in. mm
1 1
⁄2 0.840 21.3 0.86 22 0 0 ⁄16 1.6
3 1
⁄4 1.050 26.7 1.07 27 0 0 ⁄16 1.6
1 1.315 33.4 1.33 34 0 0 ⁄16 1.6
1 1
1 ⁄4 1.660 42.2 1.68 43 0 0 ⁄16 1.6
1 1
1 ⁄2 1.900 48.3 1.92 49 0 0 ⁄16 1.6
2 2.375 60.3 2.41 61 0 0 ⁄32 2.4
1 3
2 ⁄2 2.875 73.0 2.91 74 0 0 ⁄32 2.4
3 3.500 88.9 3.53 90 0 0 ⁄32 2.4
1 1 3
3 ⁄2 4.000 101.6 4.03 102 ⁄32 0.8 ⁄32 2.4
1 3
4 4.500 114.3 4.53 115 ⁄32 0.8 ⁄32 2.4
1 1 3
4 ⁄2 5.000 127.0 5.03 128 ⁄32 0.8 ⁄32 2.4
1 3
5 5.563 141.4 5.64 143 ⁄32 0.8 ⁄32 2.4
1 3
6 6.625 168.3 6.70 170 ⁄32 0.8 ⁄32 2.4
1 3
7 7.625 193.7 7.70 196 ⁄32 0.8 ⁄32 2.4
1 3
8 8.625 219.1 8.70 221 ⁄32 0.8 ⁄32 2.4
1 3
9 9.625 244.5 9.70 246 ⁄32 0.8 ⁄32 2.4
1 3
10 10.750 273.0 10.83 275 ⁄32 0.8 ⁄32 2.4
1 3
11 11.750 298.4 11.83 300 ⁄32 0.8 ⁄32 2.4
1 3
12 12.750 323.8 12.84 326 ⁄16 1.6 ⁄32 2.4
A
1 5
14 14.000 355.6 14.09 358 ⁄16 1.6 ⁄32 4.0
A
Larger sizes through 26 in., in 1-in. (25.4-mm) increments.
C585–90 (2004)
TABLE 2 Inner Diameter of Insulation Tubes
Tube Insulation
Tolerance
Nominal Size Outer Diameter Inner Diameter
Minus Plus
in. in. mm in. mm in. mm in. mm
3 1
⁄8 0.500 12.7 0.52 13 0 0 ⁄16 1.6
1 1
⁄2 0.625 15.9 0.64 16 0 0 ⁄16 1.6
3 1
⁄4 0.875 22.2 0.89 23 0 0 ⁄16 1.6
1 1.125 28.6 1.14 29 0 0 ⁄16 1.6
1 1
1 ⁄4 1.375 34.9 1.39 35 0 0 ⁄16 1.6
1 1
1 ⁄2 1.625 41.3 1.64 42 0 0 ⁄16 1.6
2 2.125 54.0 2.16 55 0 0 ⁄16 1.6
1 1
2 ⁄2 2.625 66.7 2.66 68 0 0 ⁄16 1.6
3 3.125 79.4 3.16 80 0 0 ⁄16 1.6
1 1
3 ⁄2 3.625 92.1 3.66 93 0 0 ⁄16 1.6
1 3
4 4.125 104.8 4.16 106 ⁄32 0.8 ⁄32 2.4
1 3
5 5.125 130.2 5.16 131 ⁄32 0.8 ⁄32 2.4
1 3
6 6.125 155.6 6.20 157 ⁄32 0.8 ⁄32 2.4
TABLE 3 Outer Diameters of Insulation for Nominal Pipe Sizes (NPS), in.
Pipe Insulation, Nominal Thickness
1 1 1 1
in. 1 1 ⁄2 22 ⁄2 33 ⁄2 44 ⁄2 5
Nominal
Size
mm 25 38 51 64 76 89 102 114 127
A
in. Outer Diameter, in.
⁄2 2.88 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75
⁄4 2.88 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75
1 3.50 4.50 5.56 6.62 7.62 8.62 9.62 10.75 11.75
1 ⁄4 3.50 5.00 5.56 6.62 7.62 8.62 9.62 10.75 11.75
1 ⁄2 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 12.75
2 4.50 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75
2 ⁄2 5.00 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00
3 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00
3 ⁄2 6.62 7.62 8.62 9.62 10.75 11.75 12.75 12.75 14.00
4 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 15.00
4 ⁄2 7.62 8.62 9.62 10.75 11.75 12.75 14.00 14.00 15.00
5 7.62 8.62 9.62 10.75 11.75 12.75 14.00 15.00 16.00
6 8.62 9.62 10.75 11.75 12.75 14.00 15.00 16.00 17.00
7 . 10.75 11.75 12.75 14.00 15.00 16.00 17.00 18.00
8 . 11.75 12.75 14.00 15.00 16.00 17.00 18.00 19.00
9 . 12.75 14.00 15.00 16.00 17.00 18.00 19.00 20.00
10 . 14.00 15.00 16.00 17.00 18.00 19.00 20.00 21.00
11 . 15.00 16.00 17.00 18.00 19.00 20.00 21.00 22.00
12 . 16.00 17.00 18.00 19.00 20.00 21.00 22.00 23.00
B
... 17.00 18.00 19.00 20.00 21.00 22.00 23.00 24.00
A
These are identical with pipe outer diameters (see Table 1, Columns 2 and 3).
B
Larger sizes through 36 in., in 1-in. (25.4-mm) increments.
C585–90 (2004)
TABLE 4 Outer Diameters of Insulation for Nominal Pipe Sizes (NPS), mm
Pipe Insulation, Nominal Thickness
1 1 1 1
in. 1 1 ⁄2 22 ⁄2 33 ⁄2 44 ⁄2 5
Nominal
Size
mm 25 38 51 64 76 89 102 114 127
A
in. Outer Diameter, mm
⁄2 73 102 127 168 194 219 244 273 298
⁄4 73 102 127 168 194 219 244 273 298
1 89 114 141 168 194 219 244 273 298
1 ⁄4 89 127 141 168 194 219 244 273 298
1 ⁄2 102 127 168 194 219 244 273 298 324
2 114 141 168 194 219 244 273 298 324
2 ⁄2 127 168 194 219 244 273 298 324 356
3 141 168 194 219 244 273 298 324 356
3 ⁄2 168 194 219 244 273 298 324 356 381
4 168 194 219 244 273 298 324 356 381
4 ⁄2 194 219 244 273 298 324 356 381 406
5 194 219 244 273 298 324 356 381 406
6 219 244 273 298 324 356 381 406 432
7 . 273 298 324 356 381 406 432 457
8 . 298 324 356 381 406 432 457 483
9 . 324 356 381 406 432 457 483 508
10 . 356 381 406 432 457 483 508 533
11 . 381 406 432 457 483 508 533 559
12 . 406 432 457 483 508 533 559 584
B
14 . 432 457 483 508 533 559
...