PiperBRC — Pipe Brace Demand & Selection Screen (MSS SP-127)
PiperBRC takes the horizontal seismic or wind demand from a load case and resolves the axial force and vertical reaction on one rigid pipe brace at a chosen angle, then screens the geometry against MSS SP-127's 30-degree minimum angle and 200 L/r slenderness limit. You enter the member's axial capacity and MSS spacing with their sources — the tool never supplies catalog values — and it flags mismatches against an imported SeisBrace PDF. Built for the engineer sizing or checking one brace at a time, not a full support-spacing study.
Content last reviewed · page regenerated 2026-09-24 at build.
Built and maintained by Matthew Norris, P.E. — active P.E. licensure in Arizona, California, Kansas, Missouri, North Carolina, Texas.
What it does
PiperBRC screens one rigid lateral or longitudinal pipe brace against MSS SP-127-2014a geometry limits, using demand you bring in from a seismic design force or wind load case.
Demand and reaction
Enter the horizontal load-case demand, the brace angle from vertical, the unsupported brace length and the member's radius of gyration. The tool resolves the axial brace force as the horizontal demand divided by the sine of the angle, and the vertical reaction as the horizontal demand divided by the tangent of the angle — standard two-force-member geometry for a diagonal brace.
Two geometry checks
- Angle: flags a FAIL below MSS SP-127's 30-degree minimum from vertical, and separately warns when the angle is under the 45-degree preferred orientation.
- Slenderness: brace length over radius of gyration checked against the 200 L/r limit.
Capacity and spacing — you supply the numbers
PiperBRC does not reproduce MSS SP-127 spacing/capacity tables or manufacturer product ratings. Enter the member or assembly's axial capacity and its source, plus the actual and allowable brace spacing and its source. Leave a value out entirely and its check reports REVIEW rather than a silent pass; enter a value without its source citation and the tool holds the calculation until the citation is supplied, so a check never returns PASS or FAIL without a value and a traceable source both present.
Every check rolls into one disposition — PASS, FAIL or REVIEW — captured to the Report Manager with the MSS basis, orientation, capacity and spacing source citations, axial demand, vertical reaction, L/r and disposition.
SeisBrace reconciliation and the PiperOCC handoff
Import a SeisBrace PDF
Upload a SeisBrace vendor report and PiperBRC reads it locally in the browser, pulling a reported axial demand and seismic coefficient (Cp) where the PDF text matches. Nothing is uploaded to a server. The parsed values land in review-only fields — vendor axial demand and vendor Cp — next to a project Cp you enter yourself.
Two deltas, not one merged number
PiperBRC reports the vendor demand delta (its own axial demand minus the vendor's) and the Cp delta (project Cp minus vendor Cp) side by side, and raises a standing warning whenever the two Cp values differ, since a Cp mismatch usually means a different code edition, site class or component-importance factor went into each side. A vendor-reported zero demand gets its own warning too, so an incomplete export does not read as a passing brace.
Load basis from PiperOCC
One click pulls the horizontal seismic demand from a PiperOCC handoff captured in the same browser — edition, site location and any assumed defaults are shown before you accept it, and PiperBRC leaves the field unchanged if the handoff carries no positive seismic force.
Report capture and DXF export
Add to Report Manager files the brace tag, MSS basis note, orientation, capacity and spacing source citations, axial demand, vertical reaction, L/r, both deltas and the disposition into a titleblocked, printable package alongside your other Piping Toolset captures.
A brace-detail DXF — the brace line, pipe and structure reference lines, and tag/length/angle/demand callouts, drawn with the same ASCII LINE/TEXT entity set PiperISO uses — is an Ultimate-tier export. It is a callout sketch, not a fabrication drawing, and no DWG output is generated.
Honest limits
- PiperBRC screens one brace at a time; it is not a multi-brace support-spacing study or a structural-frame analysis.
- MSS SP-127-2014a's own applicability and its ASCE 7-10 LRFD basis are not reconciled for you — check that basis against your project's governing load combinations before using a result.
- Member, attachment and supporting-structure capacities are never inferred from a catalog. You enter a capacity and a citation; the tool checks arithmetic against what you entered, not against a table it looked up.
- The SeisBrace PDF parser is a text-pattern match against the report layout it was built against. Treat every parsed value as a review input and reconcile the vendor's code edition, Cp basis and quantities by hand before the brace is selected.
- The capacity and spacing checks return REVIEW, not a silent PASS, whenever a value is missing outright — and hold the calculation with an input-error prompt if a value is entered without its source citation. That is deliberate, not a bug.
What's free and what needs Pro Plus
The load case that feeds PiperBRC's horizontal demand is documented free: the seismic design force calculator and the B31 pipe stress load-case guide cover the ASCE 7 side of the problem at no cost, and the sibling PiperOCC site-hazard tool is the Pro Plus workspace that produces the handoff PiperBRC can import.
- Free — $0: the seismic design force and load-case method pages.
- Pro — $2.99/month or $29/year: report capture, Report Manager, .pcp files, batch runs.
- Pro Plus — $7.99/month or $79/year: PiperBRC (this tool — demand, geometry screen, SeisBrace reconciliation and the PiperOCC handoff), PiperOCC, PiperEXJ, PiperHGR, PiperFLG and PiperNOZ. The monthly plan starts with 30 days free — no card needed to start; add one before day 30 to continue, otherwise the trial simply ends and nothing is charged.
- Ultimate — $14.99/month or $149/year: adds the PiperBRC brace-detail DXF export, plus PiperFEA, PiperSTR and the PiperISO premium exports.
The full matrix and billing FAQ are at /pricing/.
Demo video
A recorded walkthrough of this tool is on the way — current demos are on the YouTube channel.
FAQ
What does PiperBRC actually calculate, and what does it leave to me?
PiperBRC takes a horizontal seismic or wind demand from your load case, together with the brace angle from vertical, the unsupported brace length and the member's radius of gyration, and resolves two numbers: the brace's axial force, which is the horizontal demand divided by the sine of that angle, and the vertical reaction it delivers to the pipe, which is the horizontal demand divided by the tangent of the angle. That is standard two-force-member geometry for a diagonal brace, computed the same way every time. From there it runs two geometry checks against MSS SP-127-2014a — the 30-degree minimum angle from vertical and the 200 limit on brace length over radius of gyration — and separately warns when the angle sits below the 45-degree preferred orientation. What it leaves to you is everything that comes out of a table: the member's axial capacity, the allowable MSS spacing, and the supporting-structure and attachment capacities. You enter those with a source citation, and the tool checks your demand against your number rather than looking one up for you.
How does the SeisBrace PDF import work, and can I trust the parsed numbers?
You upload a SeisBrace PDF and PiperBRC reads the text locally in your browser — nothing leaves the tab — looking for a reported axial or brace demand and a seismic coefficient labeled Cp. When it finds a match it fills two review-only fields, vendor axial demand and vendor Cp, next to a project Cp you type in yourself from your own load case. The tool then reports two deltas side by side: the vendor demand delta, its own calculated axial demand minus the vendor's reported figure, and the Cp delta, project Cp minus vendor Cp. Whenever those Cp values differ, PiperBRC raises a standing warning, because a mismatch usually means the vendor used a different code edition, site class or component-importance factor than your project basis. A vendor PDF reporting zero demand gets flagged too, so an incomplete export never reads as a passing brace. Treat every parsed number as a starting point for reconciliation, not a verified input — the parser is a text match against a report layout, not a structured feed, and the standard warning text says so on every import.
What is the PiperOCC handoff, and how does the horizontal demand get set?
PiperOCC is the sister Pro Plus tool that develops ASCE 7 seismic and wind site-hazard demand. When you capture a load basis there, PiperOCC writes it to this browser's local storage along with the edition, the site location and a count of any inputs left at their tool defaults — nothing is sent to a server. Back in PiperBRC, the rail shows that captured load basis is available, with its edition, seismic force, wind load and capture time, and one click imports it: the horizontal load-case demand field is overwritten with PiperOCC's seismic force, and a note in the canvas records what changed. If the handoff carries no positive seismic force, PiperBRC leaves your entered demand alone rather than zeroing it out. Arriving directly from PiperOCC's own "Open PiperBRC" button runs the same import automatically. Either way, the handoff only ever sets one number — the horizontal demand — and the notice explicitly asks you to confirm direction, tributary basis and component classification yourself before the brace selection is finalized.
Why do the capacity and spacing checks sometimes say REVIEW instead of PASS or FAIL?
Because a silent PASS would be a false assurance. Leave a capacity or spacing value out entirely and PiperBRC's checks default to REVIEW rather than guessing at pass or fail, since the underlying engine deliberately does not embed MSS SP-127 capacity or spacing tables — it has no number to check against until you supply one. Enter a value but skip its source citation and the tool goes a step further: it holds the calculation with an input-error prompt asking for the citation, so a traceable number can never quietly become an untraceable PASS. Only once a value and its citation are both present does the check resolve to PASS or FAIL, comparing your calculated demand or your entered spacing against what you supplied. The spacing check works the same way across all three fields — actual spacing, allowable spacing and the MSS source citation. REVIEW is not an error state; it is the tool telling you the geometry checks are complete but the selection checks are still open. The overall disposition rolls all four checks together, so a brace cannot show an overall PASS while a capacity or spacing input is still sitting unreviewed.
What tier is PiperBRC on, and does the DXF export cost extra?
PiperBRC is a Pro Plus tool — $7.99 a month or $79 a year — alongside PiperOCC, PiperEXJ, PiperHGR, PiperFLG and PiperNOZ. The monthly plan starts with 30 days free and no card is needed to start it; add one from the customer portal before day 30 to keep going, and if no card is on file when the trial ends the subscription simply ends too, with nothing charged. That covers everything on this page: the demand and reaction calculation, the MSS SP-127 angle and slenderness screen, the capacity and spacing checks, the SeisBrace PDF reconciliation, the PiperOCC handoff, and report capture into the Report Manager. The one piece that costs more is the brace-detail DXF export — the callout drawing with the brace, pipe and structure lines and the tag, length, angle and demand text — gated to the Ultimate tier at $14.99 a month or $149 a year, the same tier that also carries PiperFEA, PiperSTR and the PiperISO premium exports. If DXF output is not something you need, Pro Plus runs this tool end to end.
Can PiperBRC design a full brace layout, or just check one brace?
One brace at a time, by design. Enter the tag, orientation, load-case demand, angle and member geometry for a single lateral or longitudinal brace, and PiperBRC screens that brace's demand, angle and slenderness, and checks its capacity and spacing against what you enter. It does not lay out a bracing scheme across a pipe run, decide how many braces a system needs or where they should go, or model the supporting steel frame the brace attaches to — those are structural-engineering decisions that belong upstream of this screen, informed by your flexibility analysis and the project's seismic or wind criteria. It also does not reconcile MSS SP-127-2014a's own applicability or its ASCE 7-10 LRFD basis against your project's governing load combinations; that is left to you, every time, because it depends on which code edition and load path actually govern the job. Think of PiperBRC as the arithmetic and geometry gate for one brace once you already know where it goes: it turns a load case and a chosen geometry into a defensible demand, reaction and PASS/FAIL/REVIEW screen, with every source captured alongside it.