28 ft is a manufacturer limit in feet (Godwin US Product Catalog 07.2015, sea-level dry-prime envelope). This page is a derived derate, not a published Nairobi curve. NPSHR is not invented here.
Interconnect — Wire navigates the six tools; Split Desk keeps the enquiry visible while you size.
Shared Duty object (proxico.duty.v1) carries Q, head/ΔP, T, medium, elevation.