Insulated Pipe Rack Spacing
Center-to-center spacing, total bundle width, and rack fit for parallel insulated pipe runs from OD.
Example
You enter
- Pipe outside diameter (in) 2.375
- Insulation thickness (in) 1
- Clearance gap (in) 1
- Number of pipes 2
- Rack / strut width (in, optional) 24
You get
- Center-to-center spacing 5.375 in
- Total bundle width (in) 9.75
No published worked example is on file for this calculation. It is checked against a hand-worked derivation of its method and an independent reference test.
Details, formula, and sources
ScopeInsulation thickness, and clearance (ASTM C585).
Formula or tableInsulated OD = pipe OD + 2 * insulation thickness; center-to-center = insulated OD + clearance; bundle width = n * insulated OD + (n-1) * clearance; pipes that fit = floor((rack width + clearance) / center-to-center).
Source and editionInsulated parallel-pipe rack spacing - center-to-center, total bundle width, and rack fit from the pipe OD, insulation thickness, and air-gap clearance - first-principles geometry; the insulated outside diameter follows the ASTM C585 nominal pipe-insulation dimensions, by name.
Free accessFirst-principles geometry. The clearance allowance and the hanger / support span (MSS SP-58) are separate checks; the mechanical contractor governs the rack layout.
What governsEstimate. AHJ and licensed mechanical contractor govern. ACCA Manual J / D / S supersede rules of thumb.
API field namespipe_od_in, insulation_thickness_in, clearance_in, pipe_count, rack_width_in, center_to_center_in, total_bundle_width_in
- Insulated OD pipe OD plus twice the nominal insulation thickness (ASTM C585 sizing); the actual jacket OD is read off the insulationASTM C585