A bolus control device for use with an injection device, the bolus control device including a valve body having a proximal end opposite a distal end. The valve body defines a fluid channel therethrough to allow a passage of medical fluid from the proximal end to the distal end. A connector is provided at the proximal end and configured for connecting to a fluid inlet line. A connector subassembly is provided at the distal end and configured for connecting to a fluid outlet line. A compressible check valve is disposed within the fluid channel, such that the compressible check valve is adjustable to control a cracking pressure at which the compressible check valve closes.