See a Double Diaphragm Pump in action here!

These pumps can be constructed in materials ranging from Aluminium, Cast iron, Stainless steel, Polypropylene, Acetal, Kynar (PVDF) and certain sizes in Hastelloy wetted parts

http://www.graco.be:8081/CISMBEN.nsf/fdf62a1dc9901317c1256e6a003156e1/53cec67eeaee50b8c1257ff70057f23e?