Pneumatic globe valve of stainless steel J641W

Pneumatic globe valve of stainless steel J641W

Pneumatic valve opening and closing pieces are plug-shaped valve flap, the sealing surface was flat or conical surface, the valve flap along the centerline of the fluid for linear motion. The movement of the valve stem in the form of lift rod (stem up and down, hand wheel does not lift), but also lift the rotating lever (hand wheel and stem rotation with the lift, the nut is located on the valve body). The shut-off valve is only applicable to fully open and fully closed, not for adjustment and throttling.

Pneumatic globe valve is generally fully open type. From the flow characteristics of consideration, globe valve and ball valve with a short stroke, fast, reliable sealing, open and close static

Torque and other characteristics, so the two products have been applied. But from the reliability considerations, the mainstream product is still a pneumatic globe valve.

Pneumatic globe valve for the stereotypes of products, according to the mode of action can be divided into single-and double-role two. Single-acting product with reset cylinder spring, with a loss of gas automatic reset function, that is lost when the cylinder piston (or diaphragm) under the action of the spring to drive the cylinder putter back to the initial position of the cylinder (stroke of the original location). Double-acting cylinder without resetting spring, push-rod advance and retreat must rely on changing the cylinder air source import and export position. As the air supply moves from the upper chamber of the piston, the plunger moves downward. When the gas source enters from the lower chamber of the piston, the push rod moves upward. Due to the absence of the return spring, the double-acting cylinder has greater thrust than the single-acting cylinder with the same diameter, but does not have an automatic reset function. It is clear that the different air intake positions cause the push rods to move in different directions. When the air intake position in the back cavity of the putter, the air into the putter forward, this approach is called positive acting cylinder. And vice versa when the intake position in the putter, the intake valve to push back, this approach is called the reaction cylinder. Pneumatic cut-off valve because the general need to lose gas protection, usually single-use cylinder.

Uses: cut-off valve is a mandatory sealed valve, so the valve is closed, the valve must be applied pressure to force the sealing surface does not leak. When the media from the valve below the valve into the valve 6, the operating force to overcome the resistance is the stem and packing friction and the pressure generated by the medium of the thrust, the force off the valve than to open the valve force, so the valve The diameter of the rod to be large, or it will occur stem top bend of the fault. From the self-sealing valve appears, the flow of the valve to change the valve from the top of the valve into the valve chamber, when the pressure in the medium under the force off the valve is small, and open the valve force, the stem diameter can be . At the same time, the role of the media, this form of the valve is more stringent. China's valve "three to" has provided that the flow of cut-off valve, all top-down