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    Layout & Access

    Layout & Access Tools

    First-pass plant layout you can defend. Each result is a typical value that points back to OSHA 1910.28, ASME B31.3, and the governing site standard — confirm before issuing.

    Pipe Rack Sizer

    First-cut rack width and level count from the pipe population, with a 20% growth allowance.

    Lines ≤ 2"
    Lines 3–6"
    Lines 8–12"
    Lines > 12"
    Rack length
    ft
    Rack Width
    15ft
    1 level
    Bays @ 20 ft
    6
    16 lines
    Rack sizing estimate

    Width sums pipe ODs plus spacing with 20% growth allowance; add a level above ~80 ft width. Bays at 20 ft, levels at 6 ft, 10 ft below-rack clearance. Verify structural design.

    Source:ASME B31.3

    Width sums ODs + spacing + 20% growth; a second level is added past ~80 ft. Bays at 20 ft, levels at 6 ft, 10 ft below-rack clearance. Confirm with structural design.

    Source:ASME B31.3

    Valve Access

    Check whether a hand-wheel is reachable from the standing surface or needs an operator aid.

    Hand-wheel elevation above surface
    in
    Reach Limit
    81in
    9 in to spare
    Hand-reachable

    Within the 6 ft 9 in (2050 mm) hand-wheel limit — no operator aid needed.

    Hand-wheels above 6 ft 9 in (2050 mm) from the standing surface need a chain-wheel, gear/motor operator, or a fixed access platform. Frequently operated valves should be at 3–5 ft.

    Platform & Ladder Access

    Check fixed-ladder fall-protection requirements and basic platform clearances.

    Fixed-ladder rise
    ft
    Min Headroom
    7ft
    over walkways
    Min Walkway
    3ft
    clear width
    Fall protection required

    Fixed ladders over 24 ft of rise require a personal fall-arrest or ladder-safety system (OSHA 1910.28 — the modern rule, not the old >20 ft cage requirement).

    Modern rule: fixed ladders with more than 24 ft of rise require a personal fall-arrest or ladder-safety system — the old "cage over 20 ft" allowance is being phased out (full compliance by Nov 2036). Keep 7 ft headroom and 3 ft walkway clearance.

    Plot-Plan Spacing

    Typical battery-limit setbacks and fire-protection spacing for an initial layout. Always verify against the site standard.

    Road Centerline
    50ft
    from battery limit
    Control House
    50ft
    from process
    Hydrant Spacing
    300ft
    along roads
    Hydrant Setback
    ≥ 50 ft
    from source
    Typical spacing — verify site standard

    Setbacks shown are common refinery/process practice (road CL 50 ft, control house 50 ft, hydrant spacing 300 ft, hydrant ≥50 ft from source). Always confirm against the owner's plot-plan and fire-protection standard.

    These are common refinery/process spacings for a first-pass plot plan. Insurer (e.g. FM Global / GAPS) and owner standards govern the final design — confirm before issuing.

    Instrument Straight Run

    Required straight run for accurate measurement, in pipe diameters, converted to feet for your line size.

    Instrument
    Pipe size
    Required Run
    20D
    Orifice (per β, up to)
    In Feet
    5.1ft
    3" line
    Straight-run requirement

    Maintain the listed upstream/downstream straight run (in pipe diameters) for accurate measurement. Insufficient run is the most common field metering error.

    Orifice upstream run depends on beta ratio and the upstream fitting — use 10–20D as a planning band and confirm against ISO 5167 / the meter datasheet. Downstream runs are shorter.

    Equipment Elevation

    Pump baseplate datum and the liquid level a supply vessel needs above the pump centerline to satisfy NPSH.

    Pump area
    NPSHr
    ft
    NPSH margin
    ft
    Baseplate Elevation
    100'-6"
    grade datum
    Vessel Level Above CL
    15.3ft
    NPSHr + margin
    Elevation reference

    Pump baseplate at 100'-6" (open) / 101'-0" (enclosed); set vessel liquid level NPSHr + margin above the pump centerline. Confirm against the project datum.

    Source:API 610

    Set the supply vessel's minimum liquid level at least NPSHr + margin above the pump centerline so NPSHa stays positive at low level. Baseplate elevations are typical datums — confirm the project standard.

    Source:API 610