A test, drain and adjustable pressure relief module for a sprinkler system has a single body with three independent and fluidly connectable flow ports. A first port of the three flow ports is fluidly connectable at an inlet side thereof to the sprinkler system. A second port of the three flow ports has an adjustable pressure relief valve removably mounted to an outlet thereof. The valve is biased into a closed position and a threshold pressure is required to open the valve and discharge fluid is selectively adjustable. A third port of the three flow ports has an open outlet end configured to removably connect with a drainage pipe. The three ports form a Tee connection and have a flow valve therebetween to selectively direct flow between an outlet of the first port and at least one of the respective inlets of the second and third ports.