Casting steel female thread globe valve

The globe valve, also known as the cut-off valve, belongs to the forced sealing valve, so when the valve is closed, pressure must be applied to the valve disc to force the sealing surface not to leak. When the medium enters the valve from under the disc, the resistance that the operating force needs to overcome is the friction between the valve stem and the packing and the thrust generated by the pressure of the medium, and the force to close the valve is greater than the force to open the valve, so the diameter of the valve stem should be larger, otherwise the failure of the stem top bend will occur

Needle valve specification

Main material sheet

Product Characteristics

1.Female thread globe valve has three kinds of connection types, they are flange globe valve, screwed globe valve and welding globe valve .

2.Globe valve is one of the most widely used valves, it is widely popular, because of the small friction between the sealing surfaces in the process of opening and closing, relatively durable, the opening height is not large, easy to manufacture, convenient maintenance, not only suitable for medium and low pressure, but also suitable for high pressure.

3.The closing principle of the globe valve is to rely on the pressure of the valve bar to make the sealing surface of the valve disc and the sealing surface of the valve seat closely fit to prevent the flow of medium.

4.As one of the most important shut-off valves, globe valves play an important role in the aerospace field. As an important component of aerospace equipment, the globe valve realizes the functions of medium transportation, cut-off and adjustment, and its sealing performance directly affects the safe and reliable operation of aerospace equipment. The influencing factors and influencing laws of typical globe valve sealing characteristics are studied, which has guiding significance for the structural design of valve sealing pairs, so as to improve the sealing performance and reliability of valves .

5.Shut-off valves are relatively simple and easy to manufacture and repair. In terms of service life, the sealing surface of the globe valve is not easy to wear and scratch, and there is no relative sliding between the valve disc and the sealing surface of the seat during the valve opening and closing, so the wear and abrasion of the sealing surface is small, so the service life of the sealing pair is improved, and the valve disc stroke is small in the process of total closure, and its height is smaller than that of the gate valve. The disadvantage of the globe valve is that the opening and closing torque is large and it is difficult to achieve rapid opening and closing, because the flow channel in the valve body is relatively tortuous, the fluid flow resistance is large, resulting in a large loss of fluid power in the pipeline.

Advantages

1.The structure of the globe valve is simpler than that of the gate valve, and the manufacturing and maintenance are more convenient.

2.The sealing surface is not easy to wear and scratch, the sealing is good, there is no relative sliding between the valve disc and the sealing surface of the valve body when opening and closing, so the wear and abrasion are not serious, the sealing performance is good, and the service life is long.

3.When opening and closing, the disc stroke is small, so the height of the globe valve is smaller than that of the gate valve, but the structural length is longer than that of the gate valve.

4.The opening and closing torque is large, the opening and closing time is more laborious, and the opening and closing time is longer.

5.The fluid resistance is large, because the medium channel in the valve body is tortuous, the fluid resistance is large, and the power consumption is large.

6.When the nominal pressure PN≤16MPa in the direction of medium flow, the downstream flow is generally used, and the medium flows upward from under the valve disc; When the nominal pressure PN≥20MPa, the reverse flow is generally used, and the medium flows down from above the valve disc. to increase seal energy. When in use, the shut-off valve medium can only flow in one direction, and cannot change the flow direction.

7.When fully open, the valve disc is often eroded.
The stem axis of the globe valve is perpendicular to the seat sealing surface. The relatively short opening or closing stroke of the stem and the very reliable shut-off action make this valve suitable for use as a medium for shut-off or regulation and throttling.