Pipe Support Submittal Package: Drawing, BOM and Tag Checklist

Why one document is rarely enough

A support schedule may tell a supplier that tag PS-101 exists, but it may not define the attachment geometry. A drawing may show geometry, but its callouts may rely on a separate bill of materials. A BOM may count components, but it may not explain whether the quantity is per assembly, per drawing, or for the full project. A packing or loose-item list may show bolts and rods that will be shipped separately, but those parts are easy to lose if they are not linked back to the parent support tag.

That is why a useful package is built around traceability rather than file count. Sending more files does not automatically make an RFQ clearer. The reviewer needs to answer five questions without guessing:

1. Which support tag is being reviewed?
2. Which drawing revision controls the review?
3. Which drawing callouts correspond to which BOM or MTO lines?
4. What is the quantity basis for the parent assembly and its loose items?
5. Which fields are confirmed, and which remain TBC?

The exact document names vary by project, EPC, owner and supplier. The buyer's enquiry instructions and document-precedence rules should therefore control. A supplier should not silently choose between conflicting revisions.

The four document layers

A revision register or transmittal is best treated as the control layer over these four records. It tells the reviewer which files were actually issued together and whether a superseded drawing is still present in the package.

Autodesk's documentation describes a bill of materials as structured component information and explains that a drawing parts list is a representation of BOM information. It also notes that static overrides can break the expected association between drawing data and the BOM. Those relationships are useful here, but the project's own document rules remain authoritative.

A five-step reconciliation workflow

1. Normalize the support tag

Choose one exact tag format and use it everywhere. PS-101, PS 101 and PS101 may look equivalent to a person, but they can behave as three different records in a spreadsheet or document-control system.

Create a tag index with one row per support tag. Preserve the source value in a separate column if normalization is required; do not erase the original reference. If one drawing applies to several tags, list the relationship explicitly rather than duplicating the drawing without explanation.

2. Freeze the revision basis

Record the drawing number, revision and issue status used for the review. If the schedule cites Rev B while the transmittal contains Rev C, mark the conflict as an open item. Do not merge dimensions from one revision with a BOM from another unless the buyer confirms that combination.

A short precedence note prevents silent assumptions:

Revision comparison is not clerical overhead. Official Autodesk guidance on BOM comparison shows why item-level additions, removals and changes need to be visible when revisions differ. For an RFQ, the same principle helps prevent a quantity or component change from disappearing inside a new file name.

3. Match drawing callouts to BOM lines

For each item balloon or callout on the controlling drawing, find the corresponding BOM or MTO line. Record both references in the reconciliation table. Item numbers are useful cross-references, but a matching number alone is not enough if the description, unit or revision basis differs.

Flag four conditions separately:

• drawing callout with no BOM line;
• BOM line with no drawing callout or parent reference;
• same item number with different descriptions;
• item described as a set, pair or lot without a defined content basis.

This step is where a supplier can identify missing information without redesigning the support. The output should be a clarification list, not an invented component selection.

4. Reconcile parent quantity and loose items

First state whether the parent quantity is per tag, per assembly, per drawing, per line, or a project total. Then state the basis for each loose item.

A useful check is:

expected component quantity = parent assembly quantity × quantity per assembly + approved spares

This is a reconciliation aid, not a universal procurement rule. It only works when the package defines the meaning of “quantity per assembly” and when spares are separately approved. A line marked 1 set, 2 pairs or 1 lot must be expanded or defined before it can be compared reliably.

Loose parts should retain a parent relationship. For example, a rod, nut or plate shipped separately should still carry the parent tag or a controlled cross-reference. Otherwise, a correct total quantity can still arrive as an unusable allocation problem at site.

5. Put unresolved fields in a TBC register

Do not fill a gap with the most likely value. Create a compact TBC register with the affected tag, source document, field, conflict, owner and required response date. This makes the package reviewable while keeping assumptions visible.

Useful TBC categories include:

• controlling revision;
• units and dimensional basis;
• material or finish specified by the buyer;
• connection and interface details;
• quantity and spare basis;
• loose-item allocation;
• inspection or documentation requirement stated in the enquiry.

If a requirement is absent from the controlled enquiry, label it “not provided” rather than implying that it is not required.

Copy-and-use reconciliation table

Add a source column if values come from more than one transmittal. Add an approval reference if a later clarification changes the issue basis. Keep superseded values in the audit trail instead of overwriting them without explanation.

Worked example: finding a quantity conflict before supplier review

Assume a schedule lists two supports under tags PS-101 and PS-102. Both point to drawing D-500 Rev C. The drawing shows item callouts 10, 20 and 30 for each parent assembly. The BOM lists item 10 as 2 each, item 20 as 1 each, and item 30 as 4 each, but its heading does not say whether those quantities apply per assembly or to the drawing total.

The correct next step is not to multiply everything automatically. The reviewer should record:

Once the buyer confirms that the BOM quantities are per assembly, the expected project totals can be calculated. Until then, two different totals are plausible, so the RFQ should preserve the ambiguity rather than hide it.

This worked example is intentionally generic. It demonstrates the review method, not the design or quantity basis for any actual project.

Fields to clarify before supplier review

Units and dimensional basis

State the measurement system and identify whether critical dimensions are nominal, center-to-center, face-to-face or finished dimensions. A unit column is safer than relying on a title-block note that may not carry into an extracted schedule.

Material and finish

Carry material grade, finish and coating as buyer-specified fields with a source reference. A workshop photo, generic product image or previous project should not be used to infer them.

Interfaces and attachments

Show the interfaces that affect the requested supply scope: pipe-side attachment, structure-side attachment, thread/interface dimensions and any companion parts. If design responsibility sits elsewhere, state the supplied boundary rather than implying a completed engineering check.

Quantity and spares

Separate base quantity, approved spare quantity and any optional quantity. State whether a BOM line is per assembly or project total. Do not combine spare and operating quantities into one unexplained total.

Document precedence

When a schedule, drawing and BOM conflict, the buyer should identify the controlling source or issue a clarification. The supplier can highlight the conflict, but should not silently decide which engineering record wins.

Common handoff gaps and their RFQ impact

Can a workshop photo replace a fabrication drawing?

No. A workshop image can show general manufacturing context or visible product form. It does not establish hidden dimensions, material grade, load basis, revision status, quantity basis or compliance. The image accompanying this draft is used only as generic factory context; it is not evidence that a particular submittal workflow was used for the photographed work.

A supplier-ready pre-review checklist

Before sending the package, confirm that:

• every in-scope support tag appears once in the tag index;
• every tag points to a drawing number and revision, or is marked TBC;
• every drawing callout maps to a BOM/MTO line or a clarification item;
• the BOM states whether quantities are per assembly or project total;
• set, pair and lot contents are defined;
• loose items retain a parent tag or controlled cross-reference;
• spares are separated from base scope;
• superseded documents are clearly identified;
• conflicts are listed in a TBC/deviation register;
• the request identifies the expected supplier response: budgetary review, quotation, manufacturability feedback or documentation check.

For the broader information a supplier may need, use the pipe support enquiry checklist. If the source is primarily a schedule, see how to read a hanger schedule. Component-level comparisons are covered separately in clevis hanger vs pipe clamp and the beam clamp and eye nut RFQ checklist. Once documents move into shipment and receipt, use the crate, packing-list and tag reconciliation workflow. You can also review the pipe-support product overview before defining the supply boundary.

Download the pre-review workbook

The editable workbook turns this guide into six working sheets: Start Here, Package Checklist, Tag Register, Document Register, Open Items and Source Notes. It includes 30 checklist items, formula-driven completion indicators, controlled status lists and fields for owners and evidence.

Download the XLSX pre-review template

Version 0.2 · Published August 24, 2026 · SHA-256: c0b8638c8bfc64910b4ebc864d84c67b36e27ed82bbb2e6bcfd56f6af32b9659. The file is a workflow aid, not an engineering approval, inspection certificate or universal project standard. Its first sheet states the use permission, copyright notice and maintenance URL.

FAQ

What is the difference between a support schedule and a BOM?

A support schedule is primarily a tag and scope index. A BOM is a structured list of items and quantities. They should cross-reference each other, but one does not automatically replace the other.

Which revision should a supplier quote against?

The revision identified by the buyer's controlled enquiry or transmittal should govern. If documents conflict, the supplier should list the conflict and request written clarification instead of selecting a revision silently.

How should loose hardware be linked to a support tag?

Use a parent tag, drawing/item reference and, where applicable, a package or box reference. The link should remain visible in the BOM, loose-item list and packing information.

What should be marked TBC in an RFQ package?

Any field that is missing, inconsistent or awaiting buyer confirmation should be marked TBC, including revision, unit, quantity basis, material/finish, interface, spares and documentation requirements.

Can a workshop photo replace a fabrication drawing?

No. A photo can provide visual context, but it cannot reliably establish dimensions, hidden construction, material grade, revision status or quantity basis.

Prepare a reviewable package

Send the controlled schedule, current drawing set, BOM/MTO, loose-item list and TBC register together. State the response you need and the date/revision basis. If you want us to review whether the package is complete enough for a supplier discussion, contact PipeAnchor Supply with the tag index and document register. Final design authority and acceptance remain with the responsible project engineer and buyer.

Technical reference basis

• Autodesk — About the Bill of Materials
• Autodesk — Tube and Pipe Drawings
• Autodesk — BOM Comparison
• LISEGA — LICAD Manual — manufacturer-specific example of pipe-support drawing output; not a universal project document rule.