es . Replacement Parts List Bac | | Zone Valves " SUPERSEDES: 104-005 dated April 18, 1987 FOR LIST PRICES REFER TO SHEET RPPS100-1. EFFECTIVE: February 1, 2000 Models 556 Medals 570 556 Models 560 571 557 561 572 5101 5 562 573 ITEM #10 ITEM #40 at DESCRIPTION VALVE AND SEAT POWER ASSEMBLY UNIT E55 T 556-2 02 WAY VALVE 125PS1 | 555-055RP 555.050RP 557.2 1 556.