Reference table
Sprinkler Pipe Internal Diameter Reference
Compare typical Schedule 10 and Schedule 40 internal pipe diameters used in sprinkler hydraulic and velocity calculations.
pipe internal diameter schedule 10 4010 rows2 linked calculators
Rows
10
Reference values
Columns
3
Lookup fields
Linked tools
2
Calculators using this data
Page role
Use this page for a defined task before moving to the next project record.
- Audience
- Engineers, designers, reviewers, and technicians selecting calculator input values.
- Job
- Use this table when a calculator needs internal diameter rather than nominal pipe size.
- Evidence
- Select nominal size and schedule together; do not use nominal size as the internal diameter. Keep schedule consistent between pipe dimension lookup, velocity, friction loss, and suction checks.
- Output
- Selected Nominal Pipe Diameter row carried into 2 calculator workflows.
- Next
- Choose the matching row, review selection checks, then open the calculator or worksheet that consumes the value.
Source governance
Record how this table is used before carrying a value into a calculator, worksheet, or authority workflow.
| Governance item | Record | Use boundary |
|---|---|---|
| Source class | Dimensional and fitting reference | Use the table as a controlled reference input, not as an adoption or approval database. |
| Last review basis | Static registry review | Re-check adopted standards, manufacturer data, and project criteria before final use. |
| Known limit | Manufacturer data, adopted edition, and project specifications can supersede a generic reference row. | Escalate unresolved code, listing, or jurisdiction questions to the project record. |
| Downstream record | Hazen-Williams Sprinkler Friction Loss Calculator, Sprinkler Pipe Velocity Calculator, NFPA 13 Hydraulic Design Worksheet, Hydrant Flow and Water Supply Worksheet | Keep selected rows with the worksheet, calculation package, or authority record. |
Reference table structure
Use these fields to filter the table, select a value, and retain the basis with the calculation record.
Rows
10
Filter fields
Nominal Size
Value columns
Schedule 10 ID (in), Schedule 40 ID (in)
Related pages
3
| Table area | Values | Engineering use |
|---|---|---|
| Query examples | Nominal Size = 3/4"; Nominal Size = 1"; Nominal Size = 1-1/4" | Use these values as table filters before carrying a row into a calculator. |
| Related calculators | Hazen-Williams Sprinkler Friction Loss Calculator, Sprinkler Pipe Velocity Calculator | Selected rows become calculation inputs or reasonableness checks for the linked tools. |
| Related worksheets | NFPA 13 Hydraulic Design Worksheet | Worksheet records preserve the selected value with the project assumption trail. |
Reference table use
Use the table as controlled input data: select the row, verify the condition, and carry the value to the related calculator.
Usage context
- 1Use this table when a calculator needs internal diameter rather than nominal pipe size.
- 2Select the schedule and nominal size that match the same pipe segment used for flow, velocity, friction loss, or suction review.
- 3Keep the selected internal diameter with the downstream hydraulic record because small ID changes can materially affect velocity and pressure loss.
Selection rules
- 1Select nominal size and schedule together; do not use nominal size as the internal diameter.
- 2Keep schedule consistent between pipe dimension lookup, velocity, friction loss, and suction checks.
- 3If manufacturer pipe data differs from this generic row, use the project or manufacturer basis and document it.
Review checks
- 1Nominal size, schedule, and internal diameter are copied together into the downstream calculator.
- 2The same internal diameter is used for velocity, velocity pressure, friction loss, or suction review where applicable.
- 3Pipe material or manufacturer data exceptions are noted before final design reliance.
| Reference field | How to use it | Related tools |
|---|---|---|
| Nominal Size | Use this field to identify the matching project condition. | Hazen-Williams Sprinkler Friction Loss Calculator, Sprinkler Pipe Velocity Calculator, NFPA 13 Hydraulic Design Worksheet |
| Schedule 10 ID (in) | Carry this value into the downstream calculator with the displayed units and label. | Hazen-Williams Sprinkler Friction Loss Calculator, Sprinkler Pipe Velocity Calculator, NFPA 13 Hydraulic Design Worksheet |
| Schedule 40 ID (in) | Carry this value into the downstream calculator with the displayed units and label. | Hazen-Williams Sprinkler Friction Loss Calculator, Sprinkler Pipe Velocity Calculator, NFPA 13 Hydraulic Design Worksheet |
Selection examples
Use these examples to choose a row deliberately before carrying the value into a calculator or worksheet.
| Scenario | Row choice | Reason | Downstream use |
|---|---|---|---|
| A 2 in Schedule 40 branch line feeds a friction-loss segment. | Select the 2 in Schedule 40 internal diameter row. | Hazen-Williams and velocity checks need actual internal diameter, not nominal pipe size. | Carry the internal diameter into Hazen-Williams, pipe velocity, and velocity-pressure checks for the same segment. |
| A preliminary design changes from Schedule 40 to Schedule 10 mains. | Select the schedule row that matches the revised pipe specification. | Schedule changes alter internal diameter and can change velocity and friction loss. | Re-run affected hydraulic segments and keep the schedule basis in the NFPA 13 worksheet. |
| Manufacturer pipe data differs from the generic reference row. | Use the manufacturer internal diameter and document the exception. | Project-specific pipe data supersedes a generic dimension table when it controls the calculation. | Attach the manufacturer source to downstream velocity, friction-loss, and pump suction records. |
Using internal diameter for one hydraulic segment
Assumptions
- 1A branch line segment is labeled 2 in Schedule 40 steel.
- 2The same segment will be checked for velocity and Hazen-Williams friction loss.
- 3No manufacturer-specific internal diameter has been provided.
Steps
- 1Select the 2 in Schedule 40 row and copy the internal diameter with the schedule label.
- 2Use that internal diameter in the pipe velocity calculator for the segment flow.
- 3Use the same internal diameter in Hazen-Williams with the segment length and C value.
- 4Retain nominal size, schedule, and internal diameter together in the hydraulic worksheet.
Result
The result is a traceable pipe dimension basis. Reviewers can see that velocity and friction loss used the same internal diameter for the same pipe segment.
Misuse warnings
- 1Do not enter nominal pipe size as internal diameter in velocity or friction-loss calculators.
- 2Do not mix Schedule 10 dimensions with Schedule 40 pipe assumptions in the same segment record.
- 3Do not ignore manufacturer or project pipe data when it conflicts with the generic reference row.
Nominal Pipe Diameter
| Nominal Size | Schedule 10 ID (in) | Schedule 40 ID (in) |
|---|---|---|
| 3/4" | 0.884 | 0.824 |
| 1" | 1.097 | 1.049 |
| 1-1/4" | 1.442 | 1.38 |
| 1-1/2" | 1.682 | 1.61 |
| 2" | 2.157 | 2.067 |
| 2-1/2" | 2.635 | 2.469 |
| 3" | 3.26 | 3.068 |
| 4" | 4.26 | 4.026 |
| 6" | 6.357 | 6.065 |
| 8" | 8.249 | 7.981 |
Engineering disclaimer
NFPA in USA provides engineering workpapers, calculation checks, and reference tables for project screening and coordination. Final design decisions, code interpretations, submittals, and acceptance records must be completed by qualified professionals and verified against the adopted code, project criteria, listings, and Authority Having Jurisdiction requirements. This site does not issue signed or sealed engineering documents.Tools and workflows that use this table
FAQ
How should this pipe dimension table be used?+
Use it as an engineering reference source for selecting values, checking assumptions, and documenting the basis carried into a calculator or worksheet.
Can this table replace the sealed project record?+
No. Values still need to be checked against the adopted standard, manufacturer data, project specifications, and Authority Having Jurisdiction requirements before they are used in final documents.