내부식성이 필요로 하는 배관에 주로 사용되며 Seat가 일체형으로 하는 경우와 분리형으로 하는 경우 두 가지가 있다.Gate Valve의 용도는 Disc를 완전히 열거나 닫아서 사용하는 것으로 유체를 차단하는 것이 주된 용도이다.기본적으로 급속 하거나 빈번한 개폐 조작을 중요시 하지 않는 배관에 사용된다.
■ YOKE SLEEVE
The upper portion of the Yoke Sleeve is hexagonally tapered to fix the handwheel. The standard material of the Yoke Sleeve is Nodular Ni-resist D2 with over 1150℃(2100℉) dissolution point in accordance with API Std. specifications.
The body-bonnet bolts are manufactured in accordance with API Std. 603 specifications. The nuts also strictly conform with ANSI B 1.1 The stud-bolt nuts, hexagonal, rigid and hot-forged, bear material notation as well as do the bolt nuts made according to ANSI B18.2.2
The bonnet and valve body have the same wall thickness. The body-bonnet flange drilling is spot-faced to exactly meet studbolt nuts. The bonnet back seat bushing guarantees packing replacement even when the valve is fully opened. The stem packing dimensions of the stuffing box are in accordance with API
The machined forged stem comes with a T-shape head, which connects the slot of the wedge. The spherically shaped contacting surface of the head gives greater strength and durability. The stem dimensions are in accordance with API Std. 603 specifications. The stem delivers adequate mechanical properties as well as excellent surface hardness. Further, opening/shutting friction is minimized by accurate machining and lapping.
■ FLEXIBLE WEDGE
The standard disc of our valves is a one-piece flexible wedge. Slots are machined on both sides of the wedge to allow it to travel correctly in the integrally cast body guides. The wedge seating surfaces have been accurately machined, grind and lapped to a mirror finish to prevent leakage and eliminate galling.
The cast stainless steel body is designed to insure a wall thickness which is greater at any point than the minimum specified by API Std. 603. Special care has been taken with the design of the Class 150 valve body so that the elliptically shaped center section is free from intensified stresses in the critical area. The body of above Class 300 are made circular in shape as much as possible to minimize distortion even under extreme operating conditions. Inlet and outlet port dimensions conform with ASME B16.34 Pipe Fitting. The weldedin type seat ring is standard to insure interchangeability. Except for Class 150, the standard body-bonnet joint is male and female.