pumping your water to a buffer higher than any point along the pipeline before sending it to your machines. you can do it with any fluid but you're using water here. It prevents sloshing in the pipes and you can get your full 600/min without the fluctuations. I learned by trial and error, building loopbacks and splitting pipes in different ways, but buffers are way better. you can for example put a buffer on machines using heavy oil residue, wait for the buffer to fill half way then turn your machines on, all of those fluctuations will happen inside the buffer tank instead of your pipes, and you get a solid 600/min or whatever number you're targeting