#5 give a good answer. P, i+ C. [ k' k9 x8 l" T/ j/ i2 A( P. K- S7 B) q8 ^0 g
cause different pressure areas , we can just apply a small pressure to enable the poppet out ) X7 Z7 u- l. [8 k$ F. n& N; @7 @! \7 ?* c$ A. o8 C
it should be a two stage valve. a little bit complex kind. once you get its working function. then it is easy for. u