I have several HOA's that seem to have been designed years ago (average 15-18) and have the same problem... Several zones have anywhere from 17-30 heads on each one and there is not enough pressure. Not sure what moron did these systems, but they are now my problem children. All have 2" mains with reducers. Some zones have PGP's and others have PS style heads (for the smaller areas). The PS areas don't have enough pressure to even pop up the heads 2" !!! and that's with 4" heads! Any help is greatly appreciated, not sure if there are pressure boosters on the market or what. To go in and re-design would be a major deal.