The People's Republic of China shipping industry standard
CB/T4248-2013 Bottom discharge screw plug
SHIP’S BOTTOM PLUGS AND SPANNERS

Bottom discharge screw plug Scope of application:
CB/T254-97 Bottom release screw plug is suitable for steel bottom oil tank, screw plug for discharging oil water, not suitable for small boats with a bottom plate thickness of less than 6mm.

An example of the marking of CB/T254-97 bottom release screw plugs is as follows:

Type A shoulderless bottom release screw plug

The cork is hexagonal, the nominal size is 30mm, the seat version h = 30mm, the stainless steel shoulderless bottom discharge screw plug used in the oil tank: discharge screw plug - bottom discharge screw AO30-30N CB/T254-97
The cork is hexagonal, the nominal size is 42mm, the seat version h = 35mm, stainless steel shoulderless bottom relief screw plug for oil tank: oil tank discharge screw plug - bottom discharge screw AO42-35N CB/T254-97
The cork is hexagonal, the nominal size is 52mm, the seat version h = 45mm, stainless steel shoulderless bottom discharge screw plug for oil tank: discharge screw plug - bottom tank discharge screw AO52-45N CB/T254-97

Type B has a shoulder bottom discharge screw plug

The plug is hexagonal, the nominal size is 30mm, the seat version h = 30mm, the stainless steel shoulderless bottom discharge screw plug used in the water tank: discharge screw plug - bottom discharge screw BO30-30H CB/T254-97
The cork is square in shape, the nominal size is 42mm, the seat version h= 35mm, the stainless steel shoulderless bottom relief screw plug for the water tank: the oil tank discharge screw plug - the bottom discharge screw BW42-35H CB/T254-97
The cork is hexagonal, the nominal size is 52mm, the seat version h = 45mm, stainless steel shoulderless bottom discharge screw plug for water tank: discharge screw plug - bottom water tank discharge screw BO52-45H CB/T254-97