Injector

An injector comprising:

• a main body portion having upper and lower sections,
• means defining a passage through said lower section of main body portion for the flow of a first fluid under pressure through said passage,
• means for interconnecting said passage with a source of said first liquid under pressure,
• a removable, cylindrically shaped orifice member received in said passage for controlling the flow therethrough,
• means defining a first opening through said lower section of said main body portion into said passage upstream of said orifice member,
• a liquid-tight canister having a flexible diaphragm mounted therein and dividing said canister into first and second pressure chambers,
• conduit means interconnecting said first opening and said first pressure chamber,
• means defining a second opening into said lower section of said main body portion at a point spaced from said passage,
• a second conduit interconnecting said second chamber and said second opening to permit the passage of a second liquid from said second pressure chamber into said second opening,
• first port means formed in said upper portion of said main body portion,
• a transparent sight gauge interposed between and interconnecting said second opening and said first port means for permitting observation of the flow of said second liquid therethrough,
• second liquid flow regulating means disposed in said first port means for regulating the flow of said second liquid therethrough,
• second port means formed in said lower section of said main body portion and communicating with said first port means in said upper section of said main body portion and said passage through said lower section of said main body section at a point downstream of said first opening,
• valve means controlling the flow of said second liquid through said second port means into said passage,
• said passage including a venturi-shaped portion for sucking said second liquid from said second port means into said passage,
• trigger means straddling said main body portion and interconnected to said valve means for controlling actuation of said valve means,
• latch means for engaging said trigger means and holding said valve in an open position thereof, and
• a calibration opening formed in said lower section of said main body portion in communication with said second port means.

In combination with a liquid-tight canister having a diaphragm separating said canister into first and second chambers, means for withdrawing a first liquid from said first chamber while filling said second chamber with a second liquid comprising:

• a flow line connected at both ends with a supply of said first liquid,
• means for pumping said first liquid through said flow line,
• means defining a venturi-shaped section of said flow line opening downstream in the direction of flow through said flow line,
• conduit means interconnecting said first chamber of said canister and said venturi-shaped portion of said flow line,
• a supply of said second liquid, and
• a conduit means interconnecting said supply of said second liquid and said second chamber of said canister,
• whereby as said first liquid is pumped through said flow line said venturi portion thereof sucks said first liquid from said first chamber of said canister and causes said second liquid to flow from said source thereof into said second chamber of said canister.