In cross head type engine, the combustion space, (formed by the cylinder liner, piston and cylinder head) and the scavenge space separated from the crankcase by the stuffing Box ( also known as Diaphragm )
The piston rod bolted to the piston and passes through a Stuffing Box (Diaphragm) mounted in the diaphragm plate. The stuffing box provides a seal between the two spaces. It stops oil from moving the scavenge space and scavenge air leaking into the crankcase.
