Inputs

Calculation note

This estimates a linear travel position. The actual fitting label and manufacturer installation instructions govern field setting.

Method

Position from cold percent = (install temperature - minimum temperature) / (maximum - minimum) x 100

Position from cold mm = total travel x position percent / 100

Expansion allowance = total travel - position; contraction allowance = position

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Formula variables

  • Total travel is the expansion fitting travel in mm.
  • Minimum and maximum temperatures define the expected operating range.
  • Install temperature places the joint within that travel range.
  • Allowances show how much travel remains toward hot and cold conditions.

Assumptions

  • The calculator distributes joint travel linearly across the expected temperature range.
  • Position from cold is measured from the cold-end travel position.
  • Expansion allowance is travel remaining toward the hot condition; contraction allowance is travel remaining toward the cold condition.
  • This calculator does not replace manufacturer instructions, fitting markings, support layout, or installation approval.

Examples

Mid-range installation. With 80 mm travel, -20 C minimum, 40 C maximum, and 10 C install temperature, the setting is 40 mm from cold.

Review condition. If install temperature is near or outside the expected range, manufacturer instructions should govern the setting.