Rheodyne Analytical Sample Injector, 7725

The patented Rheodyne MBB valve design is illustrated below. In the LOAD position, mobile phase flow from pump port to column port travels through both the rotor seal groove and the MBB passage(Position A). As the rotor seal grooves rotate to change from LOAD to INJECT, there is continuous mobile phase flow through both one rotor seal groove and the MBB passage(Position B) until the rotation stops and both rotor seal grooves are connected by the loop. Sample flow begins through the loop to the loop to the column just as all flow stops through the MBB passage(Position C). Sample flow never enters the MBB passage. Valve flow passages are 0.6 mm (0.024”) in diameter.