High pressure gate valve, also called pressure seal gate valve, is designed and manufactured in accordance with ASME B16.34, API600, featuring beautiful appearance, compact structure and reliable sealing. It is suitable for various pipes from classes 900 to 4500.
Pressure slide functional principle:
Before the high pressure spool valve is tightened, turn the tension screw to lift the cap so that the initial formation between the cap, piston ring and valve body creates a sealing condition – preload pressure on the sealing surface. As the medium pressure increases, the sealing pressure between the cap, piston ring and valve body gradually increases with the increase in medium pressure. In a self-sealing seal, the working sealing pressure at the sealing surface is composed of two parts: a preload sealing pressure and a pressure caused by the medium pressure. It should be emphasized that the media pressure in a self-sealing seal always tends to increase the seal preload pressure to improve seal performance. The higher the media pressure, the higher the operating sealing pressure and the better the sealing performance.
The main features of the high pressure valve:
① The self-sealing structure can make the connection between the valve body and the high-pressure valve cover watertight, saving labor and material, safe and reliable.
② The high pressure spool valve uses a combined structure in the self-sealing valve cover to achieve linear sealing, while the sealing ring is made of corrosion-resistant austenitic stainless steel, which prolongs the service life, thus ensuring the sealing of the valve does not leak under high pressure differences.
③ For high pressure spool valves with pressure of 2500 lb and above, the inner cavity of the valve body and the sealing ring contact area are welded with stainless steel to prevent the sealing area of the valve body from being corroded under high pressure differences by air and water, resulting in corrosion and leaks. This ensures safe and long-term operation of the valve.
High pressure valve self-sealing structure:
The pressure seal gate valve uses a sealing structure combined with the outer gasket seal and the self-sealing internal pressure seal on the stem seal to ensure that the medium does not leak. The outer shaft seal is filled with a polytetrafluorene gasket or O-ring, which is tightly pressed with the stuffing box. Under the influence of media pressure, upward pressure is generated. The higher the pressure of the medium, the greater the sealing force. This structure is suitable for high media.
