Gel pumps and pipes
Gel pumps are a very distinctive piece of senary and are found in the underground section of Portal 2.
Their purpose is to pump gel from the underground resivours of gel to the higher parts of the facility.
Gelpumps are easy to make, and can be used to add atmosphere and character to a map when used correctly.
You can find a prefab here: []
It contains the set of pipes, along with coresponding sounds, and is increadably useful if you want to implement a pump in a map of your own.
Gel pumps can be made using the following props:
place this where you want it:models/props_underground/pump_station.mdl (this is the pump)
place this prop on the side of the pump: models/props_underground/paint_distillery_tank.mdl (this is the tank on the side of the pump)
place a bended pipe on the otherside of the pump and a straight pipe on the top of the pump and you will get something like this: http://steamcommunity.com/id/commander_D/screenshot/540644195468243489/?tab=all.
heres a movie:http://www.youtube.com/watch?v=MWi5028qsK8
pipes are props and most of them is called paint_tube etc...
theres many diffrent pipes wit diffrent lod settings.
place them in your map and rotate them and move them so they are connected to whatever you want it to lead to.