an open ended section 36 34 section 36 34 includes valve seat 38 valve chamber 40 and outer end 42 connected to valve chamber 40 is bore 44 having a fluid flow restrictor 46 located at the inner end thereof and inlet 24 located at the outer end thereof in the preferred embodiment flow restricter 46 is formed with a small hole of 0 016 0 050 inch diameter valve chamber 40 has gradually increasing circular cross sections having a diameter of 0 375 at valve seat 38 and a diameter of 0 385 at location 52 the diameter of the circular cross section of section 36 34 of bore 36 from location 52 to the outer end 42 is constant for reasons to be explained below in an alternative embodiment of the housing 33 bore 34 may be positioned so that the closed end of section 36 39 of bore 36 is located on the interior wall of bore 34 as is illustrated in fig2 b the components that make up the operational valve are shown in position in fig3 tubular shaped sections 54 and 56 are located at inlet 28 and outlet 32 or bore 34 respectively so that the ends flexible tubing 26 and 30 may be slipped over the outer ends thereof in a fluid tight condition it is obvious that sections 54 and 56 may be formed integrally with housing 33 if so desired stainless steel compression spring 58 is located in section 36 39 bore 36 as shown so that in a noncompressed position one end thereof is positioned in section 36 34 of bore 36 just past vavle seat 38 and into.