\documentclass[border=3mm]{standalone}
\usepackage{luacoolprop}
\pgfplotsset{compat=1.18}

\begin{document}
\begin{tikzpicture}
\begin{axis}[
  lcp fluid=R134a,
  xlabel={$h/{\rm kJ\,kg^{-1}}$},
  ylabel={$p/{\rm bar}$},
  ymode=log,
  grid=both,
  auto node placement,
  auto node algorithm=repair,
  auto node bbox mode=oriented,
  auto node failure mode=error,
  auto node debug=summary,
  width = 20cm,
  height = 15cm,
]
  \LCPAddPHQuality[
    quality values={0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1},
    labels=true,
    sloped labels=true,
    label placement=autonode
  ]
  \LCPAddPHIsotherms[
    temperature values={-20,0,20,40,60,80,100},
    labels=true,
    sloped labels=true,
    label placement=autonode
  ]
  \LCPAddPHIsentropes[
    entropy values={1.0,1.2,1.4,1.6,1.8},
    labels=true,
    sloped labels=true,
    label placement=autonode
  ]
  \LCPAddPHIsochores[
    specific volume values={0.001,0.002,0.005,0.01,0.02,0.05,0.1},
    labels=true,
    sloped labels=true,
    label placement=autonode
  ]
\end{axis}
\end{tikzpicture}
\end{document}