RIKAZ WELDING · PIPING · TESTING
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HYDROTEST PRO

Hydrotest Pressure Calculator

Minimum test pressure per international piping and pressure-equipment codes — free, offline, no data collected.

ASME B31.3 ASME B31.1 ASME B16.5 ASME VIII API 570 ASME B31.4 ASME B31.8 B16.48 B16.20 / B16.21
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Hydrotest Pressure

Minimum test pressure per applicable code
UNITS
APPLICABLE STANDARD
DESIGN PRESSURE (MAWP)
Maximum allowable working pressure of the system
Please enter a value
ALLOWABLE STRESS AT DESIGN TEMP (OPTIONAL)
Material allowable stress at max operating temperature (for stress ratio)
ALLOWABLE STRESS AT TEST TEMP (OPTIONAL)
Material allowable stress at ambient (test) temperature
+ Add Elevation Difference (Hydrostatic Head)
HIGH POINT ELEVATION
LOW POINT ELEVATION
WATER TEMPERATURE
+ Add System Volume (for Personnel Safe Distance)
SYSTEM VOLUME CALCULATOR (OPTIONAL) SYSTEM VOLUME
Optional — used to calculate a test-specific personnel safe distance below, based on the elastic energy stored in the compressed water. Leave blank to skip.
SCALED-DISTANCE CONSEQUENCE LEVEL (Rscaled)
Only affects the VERY HIGH tier (above 2,500 kJ), where distance is calculated rather than fixed. Adapted from PCC-2 Table 501-III-1-1 for internal consistency — not a PCC-2 requirement for hydrotest.
MINIMUM TEST PRESSURE
TEST PRESSURE FACTOR
STRESS RATIO
Code reference:
🛡️ Personnel Safe Distance
📋 Recommendations
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    Water Volume

    Total fill volume for pipe segments, manifolds and equipment
    PIPE SEGMENTS
    WATER TEMPERATURE
    ADDITIONAL VOLUME (VALVES, EQUIPMENT)
    Extra volume for inline valves, vessels, manifold bodies, etc.
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    Bolts & Gaskets

    Stud bolt count, size and gasket dimensions per ASME B16.5
    NOMINAL PIPE SIZE (NPS) FLANGE CLASS (ASME B16.5) FLANGE FACING TYPE
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    Pneumatic Test Pressure

    Minimum test pressure, preliminary pressure and step procedure
    🛑Pneumatic testing requires written engineering approval and a formal safety plan before execution.
    UNITS
    APPLICABLE STANDARD
    TEST MEDIUM
    DESIGN PRESSURE
    SYSTEM VOLUME CALCULATOR (OPTIONAL) SYSTEM VOLUME
    Total internal volume of all piping, vessels and equipment in test boundary
    SCALED-DISTANCE CONSEQUENCE LEVEL (Rscaled)
    Per ASME PCC-2 Table 501-III-1-1. Only affects cases above the fixed-distance table range (>200M ft·lb / ≈271 MJ), where distance is calculated rather than fixed. 20 (code default) is the least restrictive; 2 is the fatality threshold, not a "safe" distance.
    AMBIENT / SITE TEMPERATURE
    Used to accurately estimate gas mass in the system — actual site temperature (e.g. summer in KSA) can differ significantly from a fixed 20°C/68°F assumption.
    GAS CYLINDER SPEC (FOR CYLINDER COUNT ESTIMATE)
    Default is a typical 50 L / 200 bar industrial nitrogen cylinder — replace both values with your actual supplier's cylinder water capacity and charge pressure for an accurate cylinder count.

    Blind Flange

    Required thickness per ASME VIII-1 UG-34
    UNITS
    BORE DIAMETER (PIPE ID)
    DESIGN PRESSURE
    TEMPERATURE
    FLANGE MATERIAL
    FLANGE CLASS (ASME B16.5)
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    Spade / Vent & Drain

    Spectacle blind thickness and vent/drain sizing
    UNITS
    BORE DIAMETER (PIPE ID)
    DESIGN PRESSURE
    MATERIAL

    Stored Energy Check

    Isothermal expansion energy for pneumatic test safety assessment
    ℹ️ Stored energy and safe distance are calculated per ASME PCC-2 Mandatory Appendix 501-II/501-III: E = 2.5·Pt·V·[1−(Pa/Pt)^0.286] (isentropic expansion), with safe distance from the 501-III fixed-minimum table below ~271 MJ and an uncapped scaled-distance formula (R = Rscaled × W^⅓) above it.
    UNITS
    TEST PRESSURE (GAUGE)
    bar
    Enter gauge pressure (barg). Absolute pressure calculated automatically.
    TOTAL SYSTEM VOLUME
    Include all piping, vessels, and in-scope equipment within test boundary
    SCALED-DISTANCE CONSEQUENCE LEVEL (Rscaled)
    Per ASME PCC-2 Table 501-III-1-1. Only affects cases above the fixed-distance table range (>200M ft·lb / ≈271 MJ). 20 (code default) is the least restrictive; 2 is the fatality threshold, not a "safe" distance.
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    Water Specifications

    Physical properties and quality requirements for hydrotest water
    PIPE MATERIAL
    TEST WATER TEMPERATURE
    20°C
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    Manifold Design

    Hydrotest manifold volume, sizing and pressure class
    UNITS
    MANIFOLD HEADER
    Header length
    BRANCH CONNECTIONS
    Branch length · Number of branches
    PRESSURE & RATING
    FLANGE CLASS (ASME B16.5)