% Minimal plain-TeX example using the format-specific wrapper.
\input p-luacoolprop.tex
\pgfplotsset{compat=1.18}
\LCPTSDiagram[
  fluid=R134a,
  temperature axis unit=celsius,
  isenthalp=true,
  quality step=0.2,
  enthalpy values={200,250,300,350,400,450},
  labels=true
]
\bye

.