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Electro-Static Charge Safe Flow Calculator

January 11, 2026

Static Charge Safe Flow Calculator

Results update automatically as you type. The tool calculates multiple standards-aligned model limits and highlights the most conservative (lowest applicable) maximum velocity.

Unit system

US Customary Metric (SI)

Inputs

Scenario

Transfer scenario

Filling stage

Pipe / hose geometry

Pipe size preset (optional)

Selecting a preset will fill the internal diameter field.

Internal diameter (ID)

Upstream microfilter / fine strainer present

If checked, enter downstream length (and verify it is conductive/bonded).

Downstream line type (if using a microfilter)

Length after microfilter to receiving vessel

Enabled when “Upstream microfilter / fine strainer” is checked.

Liquid (material) properties

Liquid selection

“Add” creates an in-session custom liquid preset.

Conductivity κ

pS/m

Relative permittivity εr

—

Kinematic viscosity ν (optional)

cSt

Conductivity unknown / not available

When enabled, κ input is ignored.

Electrostatic risk modifiers

Dispersed phase / contamination present (e.g., entrained water)

Use this if you suspect water-in-oil, emulsions, or suspended solids.

Post‑initial velocity cap (storage tanks)

Display rounding

Results update automatically.

Results

Most conservative maximum average velocity (minimum of applicable models)

—

Max volumetric flow rate (based on ID)

—

Governing model(s)

—

Conductivity class (IEC-style)

—

Relaxation time constant τ

—

Microfilter downstream residence time

—

Submergence guidance (informational)

—

Model outputs: each model below produces a maximum velocity. The highlighted row(s) are the most conservative and govern the final recommendation.

For engineering use, verify applicability and inputs. This tool does not replace professional judgment.

Assumptions & Applicability

Intended for liquid transfer/filling where electrostatic ignition of a flammable atmosphere is a credible concern.
Assumes appropriate bonding/grounding of conductive equipment and use of conductive fill pipes/hoses where required. Nonconductive hoses/liners can change charge behavior and may require a dedicated assessment.
Limits are based on commonly applied guidance models, including slow-start limits, vehicle loading v·d limits with a velocity cap, microfilter residence-time guidance, and a conservative approach when dispersed phases are present.
This tool does not model streaming current in detail, spark energy, turbulence factors, two-phase flow dynamics, additive chemistry, or temperature dependence. Use measured product properties and site procedures.

References

API Recommended Practice 2003, Protection Against Ignitions Arising Out of Static, Lightning, and Stray Currents
NFPA 77, Recommended Practice on Static Electricity
IEC/TS 60079-32-1, Explosive atmospheres – Part 32-1: Electrostatic hazards, guidance: