RP2 pumps are only good for transporting liquids, not storing them and, unless you know something I don't, they dont connect up the the necessary machines to make the conventional process work. Railcraft puts in tanks that RP2 is compatible with, so you could use them to pump lava into , and then wooden liquid pipes to pump it out and into the correct machines. As I said originally, you would need railcraft, which would make the whole process more expensive and unecessary anyway. Also, setting it up in the first place would be a pain too. If I am wrong, someone please correct me, however, that is my understanding.