Addition of a stem, clamp and nuts

You could draw your own, like in this example. You can then use the rput command to shift it to the desired position.

documentclass{article}
usepackage{pst-labo}

newcommand{pstClamp}{
    colorlet{myfill}{brown!60}
    % potence
    psframe[fillstyle=solid, fillcolor=myfill](-.5,-2.625)(-.25,13)
    psframe[fillstyle=solid, fillcolor=myfill](-1,8)(1.75,7.75)
    psframe[fillstyle=solid, fillcolor=myfill](-1,8.25)(-.75,7.5)
    pscircle[fillstyle=solid, fillcolor=myfill](-.375,7.875){.2}
    psframe[fillstyle=solid, fillcolor=myfill](1.5,8.15)(3,7.6)
    psframe[fillstyle=solid, fillcolor=myfill](-1,4)(1.75,3.75)
    psframe[fillstyle=solid, fillcolor=myfill](-1,4.25)(-.75,3.5)
    pscircle[fillstyle=solid, fillcolor=myfill](-.375,3.875){.2}
    psframe[fillstyle=solid, fillcolor=myfill](1.5,4.15)(3,3.6)
    % support elevateur
    pspolygon[fillstyle=solid, fillcolor=myfill, linearc=.05](.25,-.25)(3.25,-1.25)(.25,-2.25)(1.25,-2.25)(4.25,-1.25)(1.25,-.25)
    pspolygon[fillstyle=solid, fillcolor=myfill, linearc=.05](4.25,-.25)(1.25,-1.25)(4.25,-2.25)(3.25,-2.25)(.25,-1.25)(3.25,-.25)
    psline(.25,-1.25)(4.5,-1.25)
    psframe[fillstyle=solid, fillcolor=myfill](4.5,-1)(4.75,-1.5)
    psframe[fillstyle=solid, fillcolor=myfill](0,0)(4.5,-.25)
    psframe[fillstyle=solid, fillcolor=myfill](0,-2.25)(4.5,-2.5)
    % base
    psframe[fillstyle=solid, fillcolor=myfill](-1,-2.5)(5,-2.75)
}

begin{document}

psset{unit=0.5cm}
psgrid[subgriddiv=1, griddots=10, gridlabels=5pt, gridwidth=0.5pt](0,0)(20,20)
pstBallon[refrigerantBoulles, glassType=ballon]

pstClamp

rput{0}(8,8){pstClamp}

end{document}