Spring Hanger Selection, Step by Step — with a Worked Example

TECH NOTE 03 — PIPEANCHOR SUPPLY ENGINEERING · JULY 2026

This is the sizing method behind every variable spring hanger data sheet we issue. Follow it to pre-select supports yourself, or use it to sanity-check any supplier's selection — including ours.

Step 0 — collect the data

SELECTION DATA CHECKLIST — ONE ROW PER SUPPORT TAG
Item	Why it matters
Hot (operating) load	The load the support must carry in service — from stress analysis or weight calc
Travel & direction	Vertical movement cold→hot; sets variability and cold load
Pipe size & temperature	Sizes the clamp/shoe and sets material and finish limits
Elevation / headroom	Decides the arrangement — hanger, base-mounted or trapeze
Project spec & finish	MSS SP-58 or project standard; primer / epoxy / HDG

Step 1 — check load variability

For a variable spring, the carried load changes as the pipe travels. Keep the change within common design practice:

Variability = (spring rate × travel) ÷ hot load ≤ 25%. If no available spring passes, the tag needs a constant support hanger — see variable vs constant.

Step 2 — select spring rate and size

Prefer the softest practical spring (lowest rate) — it minimizes variability.
Both hot and cold loads must sit inside the spring's working range, ideally near mid-range, leaving margin at both ends of the scale.
If loads sit near the edge of one size's range, step to the adjacent size rather than accept edge-of-range operation.

Step 3 — calculate the cold (installation) load

The spring is set in the cold position so that the design load is carried when hot:

Cold load = hot load ± (spring rate × travel). Pipe moves up going hot → cold load is higher (plus). Pipe moves down going hot → cold load is lower (minus).

Worked example

Support tag: main line hanger, hot load 12 kN, thermal movement 30 mm upward, hanger arrangement, headroom available.

WORKED SELECTION — TAG VSH-EXAMPLE-01
Step	Calculation	Result
Try rate 100 N/mm	100 × 30 ÷ 12 000	25% — at the limit, no margin
Try rate 80 N/mm	80 × 30 ÷ 12 000	20% — passes with margin
Cold load (moves up)	12 kN + (80 N/mm × 30 mm)	14.4 kN
Working range check	12.0 and 14.4 kN inside selected size range	Confirm near mid-range on size chart
Order note	Travel stops fitted, released after hydrotest	Set at 14.4 kN cold position

The data sheet for this tag would state: hot load 12 kN, cold load 14.4 kN, travel 30 mm up, rate 80 N/mm, variability 20%, arrangement A, finish per spec — which is exactly the format we return for every tag on your schedule.

Common selection mistakes we catch

Sizing on cold load instead of hot load — the spring must be selected around the operating condition.
Ignoring travel direction — the ± sign flips the cold load by twice the rate×travel product.
Edge-of-range selection — no margin for load growth or field adjustment.
Forgetting hydrotest — spring supports need travel stops during hydro; we fit and tag them as standard.

Or skip the spreadsheet entirely. Send your hanger schedule to sales@pipeanchorsupply.com — we run every tag through this method and return data sheets plus an itemized quotation within 24 hours on working days.

Spring Hanger Selection, Step by Step — with a Worked Example

Step 0 — collect the data

Step 1 — check load variability

Step 2 — select spring rate and size

Step 3 — calculate the cold (installation) load

Worked example

Common selection mistakes we catch

Have a schedule ready to size?