of the central tool body section 28 as shown in fig1 a 1b sleeve 36 provides an upper enlarged portion 46 having one or more flow ports 43 sleeve 36 also provides a lower enlarged portion 47 check valve 40 is attached to the tool body 20 and can be attached to the lower enlarged portion 47 of sleeve 36 an o ring 39 can be provided as a seal in between sleeve 36 and check valve 40 check valve 40 provides a valving member 41 valving member 41 only allows flow in the direction of arrow 42 check valve 40 can be a commercially available check valve such as is sold under the trademark conbraco such as a series 61 stainless steel ball cone type check valve flow ports 44 extend between second channel 50 and first channel 23 at a position below larger diameter section 32 of first channel 23 and preferably below check valve 40 thus fluid flow can circumvent the balls plugs or darts 11 that are contained within the larger diameter section 32 or first channel 23 flow through second channel 50 thus begins in first channel 23 at a position near restriction 31 flow then circumvents the plug ball dart 11 by passing from first channel 23 via ports 43 to second channel 50 and.