Calculators — Pumps & NPSH

Two calculators sharing one physics core (frontend/lib/calculators/pumpSizing.ts): the NPSHa head balance (Crane TP-410), the ISA barometric atmospheric-pressure model, and Darcy-Weisbach + Swamee-Jain suction-line friction. pump-sizing adds a 2-point parabolic pump-curve fit and a closed-form pump/system operating-point intersection; npsh-available is a thin wrapper that imports the same npshaBreakdown() core and adds ANSI/HI 9.6.1 margin-ratio classification.