I just got my first few bronze machines and I am trying to set up the boiler. I have some buildcraft liquid pipes pumping in water to the small coal boiler from the right, and steam going out the top to another BC pipe to some tanks for storage, but after I got it going, it started trying to send steam into the water input pipe. How do I prevent this ? I was thinking an iron pipe, but I'm sure there is another (better) way. Any help is appreciated