BT1000A CONTROL VALVE Parts group BT1000A B20001 CONTROL VALVE B21001 CONTROL VALVE (COMPONENT PARTS) B21201 SWING SPOOL SECTION [COMPONENT PARTS] B21301 BOOM SPOOL SECTION [COMPONENT PARTS] B21501 STABILIZER SPOOL SECTION [COMPONENT PARTS B21601 DIPPERSTICK SPOOL SECTION [COMPONENT PART B21701 BUCKET SPOOL SECTION [COMPONENT PARTS] sale parts diagram catalog online construction equipment excavator tractor