Piping Support Spacing Reference

Maximum support spacing for steel pipe in vapor and liquid service, including MSS SP-58/69 guidance and sag and stress limits.

Max Spacing B31.1

Piping Support Spacing Reference · ASME B31.1-2020 Table 121.5; MSS SP-58/69; standard wt CS pipe

Nominal Pipe Size (NPS)	Water Service (ft)	Steam/Gas/Air (ft)	Water Service (m)	Notes
1	7	9	2.1	Small-bore lines often supported at elbows only
2	10	13	3
3	12	15	3.7
4	14	17	4.3
6	17	21	5.2
8	19	24	5.8
12	23	30	7
16	27	35	8.2
20	30	39	9.1
24	32	42	9.8	Large bore limited by deflection, not stress
DESIGN RULES OF THUMB
- Use 70% of B31.1 value for design margin (heavy insulation, harsh service).
- Max sag = L/240 for appearance, L/360 for sloped lines (condensate drainage).
- Place supports at: (1) concentrated loads (valves, flanges), (2) near changes of direction, (3) each end of pipe run.
- Max unsupported span near valve/flange = 2/3 of table value (MSS SP-69).
- For slug-prone 2-phase lines, reduce spacing 50% and add guides (MSS SP-127 rec.).
- For heat-traced insulated lines, verify support type does not short-circuit tracing.
- Spring hangers required where thermal displacement > 1/4 in vertical at support (MSS SP-58 Type 49).
- Cryogenic lines: use cold shoes; never direct clamp to insulation.

Support Types MSS SP-58

MSS SP-58 Pipe Support Type Reference · Selected types (full list: MSS SP-58-2018)

Type	Name	Use Case	Notes
1	Adjustable Steel Clevis	General horizontal hanger	Most common; adjustable rod
3	Steel Double Bolt Pipe Clamp	Heavy insulation or pipe	Used with insulation protection saddle
6	Adjustable Swivel Ring	Light, small-diameter CS pipe	Copper lines also
9	Adjustable Band Hanger	Lightweight CS, copper	Small bore <2in
12	U-Bolt	Single rod clamp	Budget option, flexible direction
24	U-Bolt	Two rod support	-
35	Pipe Roller	Slide with thermal movement	Min friction for axial expansion
39	Pipe Saddle Support	Floor-mounted saddle	Tank farms / pipe racks
41	Single Pipe Roll	Horizontal line thermal movement	Ball-bearing rolls for long runs
43	Chair / Roll Stand	Pipe slide with thermal	Used with trapeze hangers
44	Pipe Roll & Plate	Horiz thermal movement	Heavy loads; cast iron roller
49	Single Rod Spring Hanger	Thermal vertical movement <1in	Variable spring
51	Constant Support	Large vertical displacement	Requires calibration per location
55	Pipe Slide	Vertical pipe, thermal downward	Allows +/- 1/4in lateral

Source: Piping_Support_Spacing_Reference_v1.xlsx

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