Pipe Tee Calculator
Compute equal-area sharp 90° T loss h = K v_c² / (2g) from dividing or combining flow and branch or run split. Runs locally. Not catalog K, not a bend, not pipe-entrance, not pipe-exit, and not Q=Av.
Enter values to calculate.
Trust summary CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · h = K v_c² / (2g) for equal-area 90° T; dividing branch 1+q², dividing run 0.4(1−q)², combining branch 1+q², combining run q(1.55−q); plus pressure and velocity solves; + O3 mpmath tabulated head.
- Input interpretation
- Enter values to calculate.
- Result
- —
- Verified scope
- h = K v_c² / (2g) for equal-area 90° T; dividing branch 1+q², dividing run 0.4(1−q)², combining branch 1+q², combining run q(1.55−q); plus pressure and velocity solves; + O3 mpmath tabulated head.
- Assurance
- Engineering
- Declared partition coverage
- PASS · 5/5 declared partitions (head, solve, alias, awkward, invalid-domain) · Matrix
- Deferred
- Not catalog K given, not circular-arc R/D, not mitered n, not entrance/exit geometry, not a non-90° wye, and not Q=Av.
- Numerical scope
- O2: equal-area 90° T K vs a separate-module identity (≤2 ULP). Not catalog K, not circular-arc R/D, not mitered n, not entrance/exit, not a non-90° wye, and not Q=Av. ≤2 ULP vs O3 applies only to the published tabulated pipe-tee vectors. Not catalog K, not circular-arc R/D, not mitered n, not entrance/exit, not a non-90° wye, and not Q=Av.
- Known limitations
- Core CVP does not include live graph, viewport, or pointer interaction.
- Model
- Equal-area sharp 90° T head from common-channel speed, dividing or combining pattern, branch or run, and q=Q_path/Q_c. Invert v_c. Optional Δp from ρ.
- Scope
- Equal-area sharp 90° T: h = K v_c² / (2g); K referenced to common-channel speed; K is reported, not an input
- Verification
- Engine tested · Source checked · v1.0.0 · CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · h = K v_c² / (2g) for equal-area 90° T; dividing branch 1+q², dividing run 0.4(1−q)², combining branch 1+q², combining run q(1.55−q); plus pressure and velocity solves; + O3 mpmath tabulated head.· View Manifest · CVP overview · Specification
- Versions
- Calculation 1.0.0 · CVP protocol 1.0.0-proposed · Evidence 2026-09-26.o2-o3
- Verification revision
- 2026-09-26.o2-o3 · 1/1 property · digest 8a55d3597732
- Legacy regression
- 7/7 tests · Production surface contract 6/6
- Trust layers
- Verification VERIFIED · Production CURRENT · Overall CVP state: VERIFIED under CVP 1.0.0-proposed
- Reference
- O1 model · O3 expected_values · O3 numerical_behavior · O2 expected_values · O2 numerical_behavior
- Interfaces
- PASS · UI (SSR) / REST / MCP
- Supplemental domain review
- Not performed
- Named expert review
- Not performed
- CVP suite
- 5/5 golden · 1/1 CVP boundary · 2/2 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 2/2 cross-interface · 6/6 CVP contract · Manifest
- Sources
- ISO 80000-4 — Mechanics
- Idelchik — Handbook of Hydraulic Resistance
- Evidence
- 1 legacy golden · legacy regression suite · 5/5 oracle-backed golden · 2/2 invalid · Artifact integrity PASS
- Semantic contract
- PASS
Full verification
Formulas
Core equations used by this calculator.
How to use
Choose pattern
dividing (split from the common inlet) or combining (merge into the common outlet). URL field is kind.
Choose path
branch (90° takeoff) or run (straight through). URL field is path.
Enter q and v_c
q_ratio = Q_path/Q_c. v_m_s is the common-channel speed. Invert on the v tab.
Example calculations
Common configurations with formula and result.
Dividing branch, q=0.5, v_c=2 m/s
Half the inlet flow leaves through the 90° branch
Dividing run, q=0.5
Same split on the straight through
Pipe Tee calculator specification
Version 1.0.0 · Engine tested
- Engine tested 7/7 tests · Production surface contract 6/6
- Named expert review Not performed
- Calculation version 1.0.0
- Definition
- Equal-area sharp 90° T. K is referenced to the common-channel speed v_c and reported from the flow pattern and q = Q_path/Q_c. Dividing: branch K=1+q², run K=0.4(1−q)². Combining: branch K=1+q², run K=1.55q−q². Not a catalog fitting K, not a bend, not inlet/exit geometry.
- What it calculates
- Equal-area sharp 90° T head from common-channel speed, dividing or combining pattern, branch or run, and q=Q_path/Q_c. Invert v_c. Optional Δp from ρ.
- Inputs
- mode?
- kind?
- path?
- q_ratio
- v_m_s|h
- rho?
- g?
- Outputs
- h
- v
- K
- kind
- path
- q
- q_ratio
- g
- rho
- dP
- alpha_deg
- mode
- model
- Formula
h = K v_c² / (2g); dividing branch 1+q²; dividing run 0.4(1−q)²; combining branch 1+q²; combining run 1.55q−q²- Assumptions
- Equal-area sharp 90° T: h = K v_c² / (2g); K referenced to common-channel speed; K is reported, not an input
- Dividing: branch K=1+q², run K=0.4(1−q)². Combining: branch K=1+q², run K=1.55q−q². q=Q_path/Q_c in [0,1]; default g=9.80665 m/s²; default ρ=1000 kg/m³
- Not catalog minor-loss K given, not circular-arc R/D, not mitered n, not pipe-entrance geometry, not pipe-exit K=1, not a non-90° wye, not Q=Av
- Units
- SI; v_c in m/s; h in m; q dimensionless; ρ in kg/m³; Δp in Pa; K dimensionless
- Boundary conditions
- missing v_m_s, h, or q_ratio when required → MISSING_REQUIRED_INPUT
- v_m_s ≤ 0 or h ≤ 0 → VALUE_MUST_BE_POSITIVE
- q_ratio > 1 or K=0 on velocity invert → VALUE_OUT_OF_RANGE
- K, rd, n_miters, θ, α, f, Q, A, v1/v2, ri_d → MIXED_INPUT_ENCODING
- flush, circular, or unknown kind/path/mode → INVALID_MODE
- Example
- v_m_s=2 kind=dividing path=branch q_ratio=0.5 → h=K v_c²/(2g) K=1.25
- Validation cases
3 published on this page · 7/7 tests · Production surface contract 6/6 · View evidence
- v_m_s=2 kind=dividing path=branch q_ratio=0.5 → h=K v_c²/(2g) K=1.25
- v_m_s=2 kind=dividing path=run q_ratio=0.5 → K=0.1
- v_m_s=2 kind=dividing path=branch q_ratio=0.5 K=1.25 → MIXED_INPUT_ENCODING
- Sources
- ISO 80000-4 — Mechanics — Length, speed, pressureSupports: h is a head; v is a speed; Δp is a pressure
- Idelchik — Handbook of Hydraulic Resistance — Diagrams 7-18 / 7-20 No.1 (dividing) and 7-1 / 7-4 (combining), equal-area 90° TSupports: Branch K=1+q²; dividing run K=0.4(1−q)²; combining run K=1.55q−q²; K referenced to v_c. Not catalog K, not a bend, not entrance/exit
- ISO 80000-4 — Mechanics — Length, speed, pressure
- Calculation version
- 1.0.0
Background
Interpretation and common distinctions.
Compute pipe-tee loss from common-channel speed, dividing or combining flow, and the branch or run split.
Supported and not supported
Supported — h from v_c, kind, path, and q · invert v_c · API physics.fluid.pipe_tee
Not supported — catalog minor-loss K, circular-arc R/D, mitered n, pipe-entrance geometry, pipe-exit K=1, non-90° wye, Darcy f, Q=Av
Agent / API notes
Capability id: physics.fluid.pipe_tee · tool id: pipe-tee · pin 1.0.0.
{ "v_m_s": 2, "kind": "dividing", "path": "branch", "q_ratio": 0.5 }
Modes: head (default), pressure, velocity. Kinds: dividing (default), combining. Paths: branch (default), run. Errors: MISSING_REQUIRED_INPUT, INVALID_NUMBER, VALUE_MUST_BE_POSITIVE, VALUE_OUT_OF_RANGE, MIXED_INPUT_ENCODING, INVALID_MODE.
Calculator URL stays /calc/physics/pipe-tee. There is no /calc/fluid.
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Frequently asked questions
Key distinctions behind the calculation.
Is this minor-loss K?
No. Catalog fitting K is /calc/physics/minor-loss. Sending K is MIXED_INPUT_ENCODING. This page reports K from kind, path, and q.
Is this circular-arc pipe-bend?
No. Smooth R/D ≥ 1 is /calc/physics/pipe-bend. Sending rd or θ is MIXED_INPUT_ENCODING. This T is a fixed 90° junction.
Is this pipe-entrance or pipe-exit?
No. Inlet geometry is /calc/physics/pipe-entrance. Exit K=1 is /calc/physics/pipe-exit. Sending ri_d or treating this as K=1 is MIXED_INPUT_ENCODING.
Is this Q = A·v?
No. Volumetric flow is /calc/physics/flow-rate. Sending Q or A is MIXED_INPUT_ENCODING. q_ratio is the dimensionless split Q_path/Q_c.
Can I send a wye angle?
No. α is fixed at 90°. Sending alpha_deg is MIXED_INPUT_ENCODING. A non-90° wye is /calc/physics/pipe-wye.
Where does this run?
Locally in the browser by default. REST and MCP call the same fluid-engine pipeTee wrapper.