Abstract: A test tool and related method for testing a blowout preventer (BOP). The test tool includes a first sub, a first pipe adapted to be connected to, and disconnected from, the first sub, the first pipe including an external spline, a second sub adapted to be connected to, and disconnected from, the first sub, the second sub including an internal spline adapted to engage the external spline of the first pipe, and a second pipe adapted to be connected to the second sub. The test tool includes an operational configuration in which the internal spline of the second sub engages the external spline of the first pipe so that a torque is transferable from the second sub to the first pipe via at least the engagement between the internal spline and the external spline. One or more high pressure low torque (HPLT) connections are incorporated into the test tool.