A frock for stern central siphon tightness test

The utility model provides a frock for stern central siphon tightness test includes at least: two apron, the connecting rod, the connecting hole has all been opened on two apron, in the connecting hole of upper end cross -under on an apron of connecting rod, in the connecting hole of its lower extreme cross -under on another apron, two apron lie in the await measuring top of the up end of examination stern central siphon and the below of lower terminal surface respectively, two apron can be followed the connecting rod and reciprocated, and can move respectively on the up end of the examination stern central siphon that awaits measuring under and on the terminal surface, and sealing closure is on the up end of examination stern central siphon that awaits measuring and on the lower terminal surface. The utility model discloses set up the connecting rod between two apron to through two apron of threaded connection, and the nut fastening, thereby the position of two fixed apron makes its last lower extreme to the