Chemical process flow sheets TikZ/PGF

Question

I'm working with simulation and control of chemical process-systems and I'm trying to get a grip on how to make nice looking process flow sheets. On the web everybody is referring to Microsoft Visio, but I'm on a mac and I would like to make my flowsheets slightly more flexible when it comes to using different platforms. Ideally, I would like to use TikZ/PGF or similar.

Q1: Is there a TikZ library, for Chemical Engineering, similar to that of MS Visio?

Q2: Could one generate a diagram as presented below with TikZ? (...)

Q3: ... and make it easy to reproduce, i.e. start building your own library?

EDIT: Q4: How can one generate the picture? I have a problem with the repeating and rotating structures, e.g. the valves. I would prefer if I could be able to do something like this (beware pseudo code. I have no idea how I could implement this in tikz)

\documentclass{standalone}
\usepackage{tikz}

\begin{document}
\begin{tikzpicture}

def node makeValve(<relative position>)    % generates the entire valve structure as one node
def node makeCSTR(<relative position>)     % generates the entire reactor (Mr in the picture) as one node

\node[] (feedFlow) ;
\draw[->] (feedFlow)--(\makeValve(2,0))--(\makeCSTR(1,0)) ;

\end{tikzpicture}
\end{document}

Answer 1

I came across this looking for something else http://www.texample.net/tikz/examples/area/electrical-engineering/

Edit: Code for a Tikz valve is available from a link at http://old.nabble.com/Overflow-when-designing-a-shape-to31589669.html#a31589669 but from the webpage it seems the author had some problems with this, so some work may be required.

You may be able to modify some of the basic elements of these flow chart like diagrams without too much trouble.