Simply Supported Beam

Where E = Young’s modulus (MPa), I = moment of inertia (mm⁴), δ = deflection limit (mm), w = total linear load (N/mm).

Continuous Beam (3+ supports)

Reference Pipe Support Spans (Water-filled, Steel, Sch 40)

DN	NPS	Typical Span (m)
25	1″	2.1
50	2″	3.0
80	3″	3.7
100	4″	4.3
150	6″	5.2
200	8″	5.8
300	12″	7.0
400	16″	7.9
600	24″	9.8

Factors Affecting Pipe Support Spacing

• Pipe material: Higher modulus materials (steel) allow longer spans than softer materials (copper, plastic)
• Fluid weight: Water-filled pipes are heavier than gas/air lines — shorter spans required
• Insulation: Adds significant weight, especially calcium silicate or mineral wool at large pipe sizes
• Temperature: High temperature reduces allowable stress and Young’s modulus — shorter spans
• Valves and fittings: Add point loads — supports must be placed near heavy components
• Vibration: Process lines subject to vibration may need closer spacing to raise natural frequency above excitation
• Thermal expansion: Support types (guides, anchors, spring hangers) affect spacing

Deflection Limits

Standard/Guideline	Deflection Limit	Notes
General industrial	2.5 mm (0.1″)	Most common
ASME B31.1 Power	2.5 mm	Power piping
Process piping	1.5–3.0 mm	Depends on service
Gravity drain lines	Slope-limited	Must maintain minimum slope
Instrument tubing	1.0 mm	More stringent for small bore

Support Types

• Rest support (shoe): Simplest — pipe rests on a bracket. Allows axial movement.
• Guide: Allows axial movement but prevents lateral movement
• Anchor: Prevents all movement — used at equipment connections and to divide expansion loops
• Spring hanger: Supports vertical load while allowing vertical movement due to thermal expansion
• Constant force hanger: For critical high-temperature lines requiring constant support force over large movement range