Is there a way to render particles as if they were a single liquid? I don't want to use the fluid simulator beacuse i've been getting more controlled results with the particles system feature + using a guide as a force field.

What i'm trying to accomplish is water flowing inside a pipe. I don't need it to be realistic but i need an inner flow to be perceived. 

So i was thinking of using a particle system guided with the same curve that models the pipe (so it follows its shape) and maybe add a smooth modifier to the result, to make it appear as though the multiple particles are only one fluid.

Of course if you think there's a way to achieve this easily with the fluid sim, or maybe there are ways to control it more preciselly, I will be glad to listen to your suggestions. But if what i'm asking is possible i would like to go that way or even a lower-tech solution (without any kind of simulation at all!)

Thanks!
If you set up a particle system that works, you can use metaballs as the object it emits, so it looks like it's one smooth "fluid". Metaballs will merge together into one smooth shape. The result isn't perfect, but it's decent: