What this tool does
Selecting a variable spring hanger is a small problem that is tedious in exactly the way that invites mistakes. You have a hot load and a cold load, a travel, and a catalog of spring sizes and travel series — and you need the selection whose working range brackets both loads, whose spring rate keeps load variability inside the limit your specification allows, and whose physical dimensions actually fit the space between the pipe and the steel. Do it by hand and you are cross-reading a load table, a rate table and a dimension table for every candidate. Do it under schedule pressure on forty supports and something eventually gets read off the wrong row.
This tool does that selection against Piping Technology & Products catalog data and then keeps going: it builds the hanger assembly, draws it in 3D, produces a hardware bill of materials with capacities checked, and prints a submittal sheet. It covers PT&P variable springs (Figures PTP-1, 2, 4, 6 and 8), DST compact springs in CS and SS series, Figure 400, and the associated hanger hardware.
Why the evaluation grid matters more than the answer
Most selection programs hand you one recommendation. This one shows the full evaluation grid — every spring size against every travel series, with the passing combinations marked — and lets you click any passing cell to override the default pick.
That is a deliberate design choice, because the "best" selection is rarely a pure calculation. A support one size up may be the right call because it standardises with the four hangers either side of it and simplifies the purchase order. A different travel series may be preferable because its dimensions clear an obstruction the calculation knows nothing about. A lower spring rate may be worth taking when the line is close to a piece of rotating equipment and you want the load variability well under the limit rather than merely inside it. Seeing which alternatives pass — and by how much — is what lets you make that judgment instead of taking the first valid answer.
The three steps
- 1 — Spring selection. Enter the design inputs (hot and cold loads, travel, direction), read the full evaluation grid, and pick the selection. Catalog dimensions for the chosen unit come up alongside it, so the fit check happens in the same place as the load check rather than two documents later.
- 2 — Assembly and 3D drawing. Configure the assembly around the selected spring — rods, clamps, and the hardware that connects the pipe to the steel — and orbit the resulting 3D model to check it makes sense. The bill of materials builds from that configuration, with every component's capacity checked against the greater of the hot and cold load, and hanger rod capacities taken from the PT&P tables at 650 °F.
- 3 — Submittal sheet. Add the project data and print the submittal: the selection, the component dimensional data, and the assembly, in a sheet a vendor or a checker can act on.
Where the data comes from — and the three typos we corrected
The engineering data is embedded from published Piping Technology & Products catalog pages and selection programs: the variable spring load and travel table, the Figure PTP-1/2/4/6/8 dimension tables, the Figure 400 table, the DST compact spring CS and SS selection programs, and hanger hardware figures 20 through 140. The specific document revisions are cited in the note at the foot of this page.
Three typographical errors in the published load tables were found during transcription and corrected in the embedded data — at size 220 row 6, at size 120 row 26, and in the PTP-8 rate at size 220. They are named here rather than fixed quietly because a corrected number that nobody is told about is indistinguishable from a wrong one: if you cross-check this tool against a printed table and hit a disagreement at one of those three points, that is why.
This is a design aid built on a manufacturer's published data, and it is not affiliated with, endorsed by, or maintained by PT&P. Final selections must be confirmed with the manufacturer and with the project's own pipe stress analysis.
What it does not do
It sizes and assembles a support; it does not tell you the support belongs there. The hot and cold loads it works from come out of your flexibility analysis, and nothing here checks whether the support scheme those loads came from is correct. Specifically, it does not model the piping system, does not compute load distribution between supports, does not evaluate the attached structural steel, and does not perform any code stress check.
It also stops at the spring and its assembly. Rigid supports, constant-effort supports, snubbers, sway braces and struts are outside its scope, as are supports from any manufacturer other than the catalogs named above.
The free calculators that cover the same ground
Several of the checks around this tool are free, need no account, and run entirely in your browser:
| Check | What it answers |
|---|---|
| Spring hanger variability | Load variability from spring rate and travel, against the MSS SP-58 25% limit — the criterion that decides whether a candidate spring is acceptable at all. |
| Pipe support spacing | How far apart the supports go, which sets the load each one carries. |
| Pipe thermal growth | The movement between anchors that becomes the travel a variable spring has to absorb. |
| AISC steel member check | The support steel the hanger assembly ultimately hangs from. |
Hanger assemblies configured here can be imported into the browser isometric drawing tool, so the support data stays with the drawing rather than living in a separate spreadsheet.
Demo video
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ASME B16.5 Flange, API 610 Nozzle Load & Spring Hanger Calculators - Piping Toolset Pro Plus (2:57) — PiperHGR spring selection with the 3D hanger assembly and submittal datasheet, then the other two Pro Plus tools: PiperNOZ nozzle load checks and PiperFLG flange analysis. Watch on YouTube.
Getting access
PiperHGR is part of Pro Plus, at $7.99 / month or $79 / year — save 18%, which also includes PiperNOZ nozzle loading and PiperFLG bolted-flange analysis. Checkout is Stripe-hosted and no account is needed beforehand. Everything on the calculator side of the site is free permanently, with no account and nothing to cancel — see pricing for the full feature matrix.