CRN Design Drawings: Pressure Boundary, Weld Maps, Revisions

By Kopfkino Consulting Corp. · Published September 11, 2026 · Updated October 17, 2026 · 8 min read

CRN design drawings must define the pressure boundary, match the calculations, and show materials, welds, nozzles, design conditions, and the nameplate. How to keep revisions controlled.

Design drawings for a Canadian CRN submission must define the registered pressure boundary, carry one frozen revision that matches the calculations, and show what a design surveyor needs: materials, thicknesses, weld details or a weld map, a nozzle schedule, design conditions, and a nameplate facsimile with a blank CRN field. The RBQ requires detailed technical drawings signed by an engineer for boilers and pressure vessels; TSSA's National Service BPV path asks for stamped drawings; Technical Safety BC requires drawings within its portal checklists. A sales general arrangement, a 3D screenshot, or a P&ID alone is not a vessel registration drawing. Expedited review tests drawing/calculation agreement and file hygiene; it does not issue a CRN or convert a concept sketch into a fabrication design.

The 24-hour and 48-hour options are expedited engineering review, technical validation, documentation review, dossier preparation, and submission-readiness services. They are not a promise that a provincial regulator, authority having jurisdiction, or registration body will issue a CRN within 24 or 48 hours.

What is a CRN registration drawing?

A CRN registration drawing (design registration drawing) is the controlled engineering drawing (or drawing set) that defines the pressure-retaining design an authority having jurisdiction (AHJ) is asked to register. It is the design of record: the calculations, datasheets, and eventually the nameplate all trace back to it. Registration attaches to the design shown on that drawing at that revision, which is why revision control and drawing/calculation agreement dominate CRN completeness failures. Marketing renderings, uncontrolled extracts, and catalogue art are not registration drawings.

How this article relates to Kopfkino's documentation-checklist page

Kopfkino's design-documentation checklist service page summarizes drawing requirements inside the full submission package. This article goes deeper on the drawing set itself (pressure-boundary definition, weld maps, title-block identity, revision discipline, and nameplate content), because most incompleteness failures are drawing failures wearing calculation clothing: the numbers exist, but the picture does not match.

Drawing types and what they are for

What a vessel registration drawing should show

Without pretending to reproduce CSA B51's entire drawing list:

• Legal manufacturer name, drawing number, revision, and date
• Code and edition
• Design conditions (MAWP, temperatures, MDMT, corrosion allowance, PWHT and radiography if applicable)
• Material specification for each pressure part
• Thicknesses
• Nozzle schedule (size, rating, service, projection)
• Weld symbols or a weld map tied to WPS numbers
• NDE and hydrotest requirements
• Support type
• Nameplate location and content, including a blank CRN field
• Written exclusions ("piping by others")

If any of those live only in an email, the drawing is not ready.

Title block as identity control

The title block is where manufacturer-of-record fights start. It should show the legal manufacturer name (matching the quality certificate, or a documented relationship), the drawing number and revision, the code and edition, and the design conditions or a pointer to the conditions table. A distributor's logo on an OEM drawing without a manufacturer-of-record structure is a review-gate fail (Quality-Control Documentation for CRN Submissions), and a title block that still shows last year's company name after a merger is an identity problem waiting for an AHJ comment.

Weld maps a surveyor can use

A weld map assigns joints to WPS numbers that exist in the welding package (CRN Welding Documentation: WPS, PQR, and Procedure Registration). If the map lists WPS-12 and the PQR package covers WPS-3 through WPS-9, the drawing is not ready. If the MDMT requires impact-qualified procedures, the map must not point at a WPS that cannot weld that MDMT.

Nameplate facsimile: blank CRN, honest fields

Show MAWP, temperatures, MDMT, manufacturer, drawing number, and a blank CRN field. The RBQ states that boiler and pressure vessel nameplates shall include the CRN, that is a completed-plate requirement after issuance, not permission to guess at the factory. After issuance, stamp the number from the registration letter; do not pre-stamp a cousin vessel's number or append suffix digits from an internet table. Confirm the issued CRN against the registration letter.

P&ID and GA: supporting, not substituting

P&IDs define piping battery limits and tags; skid GAs define object splits. Neither replaces a pressure-boundary fabrication drawing. A 24-hour request that attaches only a GA should be gated; a 48-hour cycle can use the GA to split objects and then demand the real vessel drawings from sub-vendors.

Revision control

One revision. Calculations match it. The datasheet matches it. Manitoba ITS reminds applicants that registration does not relieve the designer or constructor of responsibility, revision chaos fails that responsibility before the AHJ even looks. If the shop already cut steel to a different revision, stop: photograph as-built and move to the Emergency CRN Support for Equipment Already Fabricated recovery path rather than forcing a new-construction review.

Exclusions written on the drawing, not in a hallway

If piping is by others, say "piping by others" on the drawing. If a jacket is not in this registration, say so with a code basis, or include it. A skid GA can carry the package-level exclusions; each vessel drawing should still stand alone as a registrable article. Reviewers should not have to hunt message threads for scope.

Authentication graphics versus real seals

A CAD title block that says "approved" is not an Ontario professional engineer seal or an RBQ engineer signature. Where the chosen path requires authentication (RBQ engineer-signed drawings for boilers and vessels, Ontario professional engineer seals on TSSA National Service BPV drawings) plan the real seal before the expedited clock starts, and confirm the current requirement with the applicable AHJ.

Expedited-service relevance

24-hour: the drawing exists; review checks drawing/calculation agreement, nozzle coverage, nameplate, and file hygiene. 48-hour: rebuild a registration drawing set from fabrication drawings that contain the information but are not organized for an AHJ. Not a 48-hour product: creating a first-time design from a concept.

Practical scenario

A packager sends a skid GA with vessels shown as boxes, for a multi-province oil-and-gas project. That GA is useful as a boundary drawing and useless as a vessel CRN drawing. The review asks for the sub-vendor vessel drawings; they exist, at a frozen revision with matching calculations, so 24-hour review proceeds on those drawings while the GA supports the package object split. If the sub-vendor drawings had not existed, no review clock should have started.

Documentation checklist

• Frozen revision
• Pressure-boundary drawing, not only a GA
• Nozzle schedule
• Nameplate facsimile with blank CRN field
• Weld map tied to existing WPS/PQR
• Matching calculations
• Engineer authentication where required
• File format per the destination AHJ's current instructions
• No guessed CRN digits on the plate

Common mistakes

1. P&ID submitted as a vessel drawing
2. Mixed revisions across drawing, calculations, and datasheet
3. Missing nameplate facsimile
4. "Typical nozzle" when nozzles differ
5. Distributor name on the title block without manufacturer-of-record control
6. Stamping a CRN that has not been issued

Frequently Asked Questions

What drawings are required for CRN registration in Canada?

Pressure-boundary fabrication drawings of the object being registered (with materials, thicknesses, nozzles, welds, design conditions, and a nameplate facsimile) plus supporting P&IDs and general arrangements for packages and piping systems. The RBQ requires detailed technical drawings signed by an engineer for boilers and pressure vessels. Exact drawing content varies by jurisdiction and equipment type; confirm the destination AHJ's current drawing requirements before filing.

How should design drawings be prepared for a CRN submission?

Freeze one revision; make the calculations and datasheet match it; show the pressure boundary, nozzle schedule, weld map, and nameplate with a blank CRN field; authenticate the drawings where the jurisdiction requires (RBQ engineer signature, or Ontario professional engineer seal on the TSSA National Service BPV path); and organize files per the AHJ's current format instructions. A pre-filing drawing review verifies all of this against the live checklist.

Do CRN drawings have to be in SI (metric) units?

Follow the destination AHJ's guidance; there is no single Canada-wide rule this article can assert. Dual dimensions are often the practical path for foreign manufacturers whose shop drawings are in U.S. customary units. What is not acceptable is mixing unit systems between the drawing and the calculation report, or converting units on one document but not the other, inconsistency is a classic review comment.

Can a 3D CAD model serve as the design of record for CRN?

No. A 3D model or rendered view may clarify geometry for a reviewer, but the design of record is the controlled 2D fabrication drawing set (or a controlled 2D extract of the model) that carries the revision block, conditions, materials, and weld information and matches the calculation report. Registration attaches to that controlled document, not to a model file that can change silently.

What if the only signed drawing is in a language other than English or French?

Create a controlled bilingual or English design of record at the same revision, translated under document control, and submit that. Uncontrolled extracts and partial translations are how applications bounce, the surveyor must be able to read the conditions, materials, nozzle schedule, and notes. Confirm any language requirements with the destination AHJ; Quebec filings may involve French-language expectations.

Key Takeaways

• The drawing is the design of record; registration attaches to it.
• Revision match across drawing, calculations, and datasheet is non-negotiable.
• GAs and P&IDs support; they do not replace pressure-boundary drawings.
• Expedited review checks agreement and hygiene; it does not redraw designs.
• AHJs register the design shown on those drawings, and issue the CRN.

Next Steps

Have a complete technical package and an urgent Canadian project? Kopfkino's expedited review service can assess documentation, identify submission gaps, and prepare a submission-ready CRN dossier under available 24-hour or 48-hour service options, subject to project scope, technical complexity, and documentation completeness. Final registration remains with the applicable Canadian authority. Contact us to send your package for a completeness and submission-readiness review.

Related Guides

• What Is a Submission-Ready CRN Dossier? Documents, Structure, and Quality Gates
• Pressure Vessel CRN Canada: Submission-Ready Dossier Guide
• Pressure Piping CRN in Canada: Triggers & Dossier Readiness
• Skid Package CRN Strategy: Vessel, Piping & Fitting Split
• CRN Engineering Calculations: What Submission Reviewers Check
• Common CRN Deficiencies: A Pre-Filing Red-Team

Sources

• TSSA About CRN
• TSSA National Service
• ABSA Design Registration
• Technical Safety BC Design Registration
• Technical Safety BC document checklists
• TSASK Design Registration
• Manitoba ITS Design Registration
• RBQ Register your pressure vessel design
• CSA B51
• ASME

Regulatory references in this article were checked against publicly available authority pages as of 11 September 2026. Confirm current requirements with the applicable AHJ.

Topics: CRN Registration, CRN Documentation, CRN Design Drawings