Abstract: A Y-ram tester for the testing of the blowout prevention apparatus of a gas or oil well. There is a well casing, a well casing segment mounted thereon, and a blowout preventer which has a pair of pipe rams and is mounted on the well casing segment. The rams are adapted to tightly seal around the two pipes. A test plug is mounted in the well casing in a manner so that the test plug would not move any further into the well casing. Two pipes extend through the center passage of the blowout preventer to a position past the pair of rams. There is also means for injecting water at high pressure into the cavity formed by the central passage of the blowout preventer below the pair of rams, the central passage of the well casing segment and the central passage of the casing of the well casing above the test plug.