\usemodule[t][luacoolprop]
\pgfplotsset{compat=1.18}
\starttext
\LCPDeclareFluid{R134a}
ConTeXt MkIV installed-tree test: \LCPFluidName,
$p_c=\LCPFluidPcritBar\,\mathrm{bar}$.
\LCPHSDiagram[fluid=R134a,quality values={0,1},labels=true,
  axis options={width=6cm,height=4cm,auto node debug=summary,
    auto node allow outside=true,
    auto node failure mode=error}]
\LCPPTDiagram[fluid=R134a,temperature axis unit=celsius,
  pressure axis unit=bar,
  axis options={width=6cm,height=4cm}]
\stoptext

.