Investment Casting Screwed Gate Valve

The stem nut of the hidden gate valve is directly contacted with the medium in the valve body. When the gate is opened and closed, it is realized with the rotating stem. The advantage of this structure is that the height of the gate valve keeps constant, so the installation space is small, and it is suitable for large caliber or gate valves with limited installation space. Such a structure should be equipped with an opening and closing indicator to indicate the degree of opening and closing.

KOSEN Cast steel Gate Valves are primarily used for stop valves fully opened or fully closed .They are not normally considered for throttling purposes,but more for slurries,viscous fluids,etc. Gate valves are characterized by a traveling wedge ,which is moved with the operation of the stem nut. Gate valves usually have a minimum pressure drop when fully open,provide tight shut-off when fully closed,and remain relatively free of contamination buildup.

KOSEN Pressure Seal Gate Valves is a valve realizing the closing and opening function by lifting the disc up&down as the closure member. The main advantages of API Stainless Steel Gate valve are smooth flowing passage, small flowing resistance and small operation torque, while the main disadvantages of this valve are: easy-damaged sealing face, long closing&opening time, large volume&weight. Gate valve is widely used on pipeline as it's suitable to be manufactured with big size. Gate valve is and generally for cutting off purpose but not intended to be used as a regulating valve because the sealing face would be corroded by the medium easily when valve is not in fully open or closed position.

KOSEN Forged Steel Gate Valves are suitable for using on various kinds of pipeline cut off or connect the flowing of medium. By using different material, the valves could be suitable for medium such as water, steam, oil, nitric acid, acetic acid, oxidizing substance, carbamide and etc. Molded flexible graphite is used for packing of Female Threaded Gate Valve. PTFE or combined packing material can be also used if being requested by the customer. The internal surface of the stuffing box, of which area is contacted with the packing, is of excellent finish (Ra 3.2μm). The stem surface, contacting with the packing, should be rolled and pressed after being precisely machined, so as to reach to the high finish and compactness (Ra 0.8μm) and ensure the reliable tightness of the stem area.