Abstract: A hydrogen sulfide analyzer that continuously samples waste water from a waste stream or reservoir and measures the concentration of purgeable H.sub.2 S present (H.sub.2 SP) This information, when combined with the volume of water present, provides a control quality signal that regulates the feed rate of the destructor chemical into the waste stream. This results in chemical savings for the user. A second result is the reduction in odor complaints and the corrosion problems associated with H.sub.2 S emissions. The analyzer measures only the purgeable H.sub.2 S contained in the liquid sample. The analyzer violently agitates the sample containing dissolved H.sub.2 S in solution to simulate actual conditions at points of agitation in the waste water stream. It also provides nearly optimal partial pressure conditions for the H.sub.2 S to exit the solution as a free gas. Any H.sub.

Abstract: A combination fuel pressure regulator and fuel filter apparatus for vehicle fuel systems has a fuel supply tank with a fuel pump therein for puming fuel to a fuel supply rail having fuel injectors attached thereto. A fuel filter is operably disposed between an inlet supply tube and a fluid outlet tube for filtering impurities from fuel passing therethrough. A valve in fluid communication with the inlet supply tube is provided with a regulator for causing flow to be short circuited back into the fuel supply tank when the pressure in the fluid outlet exceeds a predetermined level. The valve is biased to a closed position and will remain closed as long as the pressure on the clean side of the filter is below the predetermined pressure whereby all of the fuel in the inlet supply tube will pass through the filter.