81 and output block 82 spacer 86 is optional but may be desirable to enable an embodiment of the invention to be assembled from existing components other embodiments of the invention may accomplish the same result by extending the top of the stem of opening valve 2 or the bottom of the piston of low pressure pilot valve 3 if required it is also preferred but not required to include an output fitting 16 such as a polyconn plymouth minn model pc122b brass hex nipple in any required size e g u00bc u2033 npt m dampening oriface 5 may be a commercially available component such as a type ia oriface available from o 39 keefe controls company monroe conn fig3 and 4 illustrate preferred components and constructions of two way normally closed valve 2 low pressure pilot valve 3 and adjustable sequencing latch valve 4 fig3 shows that two way normally closed valve 2 comprises valve stem 22 and three o rings 21 low pressure pilot valve 3 comprises low pressure piston 31 and u cup 32 two way normally closed valve 2 and low pressure pilot valve 3 are arranged on a common central axis and separated by spacer 86 fig4 shows that adjustable sequencing latch valve 4 comprises spring retainer 41 broached insert valve guide 42 spring 43 x ring.