Mechanical Insulation Design Guide - Design Objectives

by the National Mechanical Insulation Committee (NMIC)

Last updated: 06-19-2014

Personnel Protection Calculator for Horizontal Piping

This calculator estimates maximum contact exposure times on the outer surface of a horizontal pipe insulation system based on the potential for contact burn injuries.


  • Line 1. Select Nominal Pipe Size, NPS
  • Line 2. Enter operating (process) temperature
  • Line 3. Enter temperature of the air surrounding the pipe
  • Line 4. Enter the wind speed of the ambient air (if unknown, use 0 mph for worst case conditions)
  • Line 5. Select an insulation material
  • Line 6. Select the effective emittance of the exterior surface

Note: Maximum contact times calculated via procedure from ASTM C 1055 (Fig 1, Threshold B- Reversible Epidermal Injury).

Note: Calculator does not screen for material temperature limitations - Use caution.

Note: Note NA = Not Available. Some sizes and thicknesses may not be commercially available and some materials are available in sizes and thicknesses not listed.


  • One dimensional, steady state heat transfer
  • Base structure is a horizontal steel pipe
  • Thermal conductivity based on ASTM Specification Values. Refer to the introductory notes for further clarifications.
Input Information
1. Select Pipe Size, NPS
2. Operating Temperature, °F
3. Ambient Temperature, °F
4. Wind Speed, mph
5. Select Insulation
6. Select Emittance of Surface