of the bowl 26 this device 30 rests on a series of ribs 35 so that the existing port 8 of the cartridge is driven upward relative to its position in the bowl 4 as the bowl 4 is attached to the head 2 ensuring a good seal with the port 10 of the head 2 additionally the device 30 either is of a width or has flanges wings or other such devices 36 extending from it at a width that ensures the cartridge 6 is concentrically aligned within the bowl 4 such that the two ports 8 10 are aligned for proper sealing a third embodiment shown in fig6 uses an alignment device 40 similar to that of the second embodiment except that the width of the device or any of its features does not provide vertical alignment or centering of the cartridge 6 with the port 10 of the head 2 this embodiment adds a second alignment device 42 that is releasably secured to the body 44 of the cartridge 6 somewhere along its length intermediate between the end 32 adjacent the bottom and the end adjacent the port 8 this second device 42 provides the centering capabilities to the.