Appearance	Type	General Characteristics
	WAFER	The valve to be installed with long bolts between the  flanges at adjacent pipe without flange on the valve.  Easy handling and light weight.  Less quantity of bolt and easy installation.  Convenient maintenance of adjacent pipe.
	SEMI-LUG	Similar as wafer type except a pair of the thread bolt hole  in way of the upper and lower sides for easy maintenance of  adjacent pipe.  Easy handling and light weight.  Less quantity of hole and easy installation.  Keep liquid remained during repairing adjacent pipe.
	FULL-LUG	Ring shape bolt hole for bolting with flange.  Keep pressure inside during repairing adjacent one side pipe.  Different flange shape.  Possible damage on full face gasket.  Hard repairing corroded bolt.  More man-hour for installation.  Heavy weight and more cost
	FLANGE	Both ends with complete flange.  Suitable for general pipe flange.  Suitable for shipside valve in the ship.  Heavy weight and more cost.  More man-hour for installation.