Nominal pipe size in inches as a string matching the reference tables. Examples: '1/2', '1', '2', '4', '6', '8', '12', '24'. Typical range: 1/2 to 36 inches.

Pipe material. Determines the applicable MSS SP-69 support span table and the modulus of elasticity used in fallback calculations. If omitted, defaults to carbon_steel.

Service condition — affects contents weight and span table lookup. Water-filled pipes are heaviest and have the shortest spans. Gas and empty have negligible contents weight and longer allowable spans. If omitted, defaults to water.

Pipe schedule for wall thickness and weight lookup. Common values: '5', '10', '40', '80', '160', 'STD', 'XS', 'XXS'. Schedule 40 is standard for most applications. If omitted, defaults to 40.

Insulation thickness in inches. Adds weight to the total linear load. Typical range: 0.5 to 4.0 inches depending on pipe size and temperature requirement. If omitted, defaults to 0 (no insulation).

Insulation density in pounds per cubic foot. Typical values: 3-6 pcf for calcium silicate, 6-12 pcf for fiberglass, 8-15 pcf for mineral wool, 2-4 pcf for elastomeric foam. If omitted, defaults to 12.0 pcf (typical fiberglass).

Total pipe run length in feet. If provided, the calculator determines the number of support points needed. Typical range: 10-500 ft. If omitted, number of supports is not calculated.

Operating temperature in degrees Fahrenheit. If above 750 F for carbon steel, the tool flags that spring hangers or constant-force supports should be evaluated per MSS SP-69 high-temperature guidance. If omitted, no temperature advisory is generated.