2 of the cycle which is not depicted on a drawing fluid in conduit a1 will pass through stator port 70 rotor opening 66 crossover pipe 67 rotor opening 68 and port 69 in order to flow into conduit b2 during step 2 openings 62 and 64 and crossover pipe 63 will not serve as a fluid transfer path as they do during step 1 the ports are spaced 60 u00b0 apart while the openings are spaced 30 u00b0 apart the rotor assembly indexes through 30 u00b0 in moving from its step 1 position to its step 2 position opening 62 will not be in register with any port during step 2 it will be sealed or 34 blanked off 34 by the stator seating surface at a point located midway between ports 70 and 71 note that the rotor assembly of step 1 of fig6 has a configuration identical to the rotor assembly of the fig8 example and is depicted in the same position thus step 2 of fig6 also depicts the rotor of this example in its step 2 position during step 3 openings 62 and 64 and crossover pipe 63 will again serve as a fluid transfer path carrying fluid between a6 and b2 this pattern is consistent throughout the cycle and applies to all of the crossover pipes and rotor openings in this example there are twelve crossover pipes and six cycle steps so only six crossover pipes and associated openings are in use at any one time it is important to note that the complete cycle of six steps requires only 180 u00b0 of rotation of the rotor relative to the stator this.