PP Globe Valve characteristics PVDF Globe Valve advantages PPH Globe Valve Working principle

July 13, 2022

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

Valve plays an cut off in its line in the medium and the important role of throttle, cut-off valve, as a kind of extremely important truncated class valves, which exert torque on the valve stem seal, valve stem in axial direction to the pressure on the disc, the valve sealing surface and the valve seat sealing surface fit closely, prevent leakage of medium along the gaps between the sealing surface.

Globe valve (Stop valve,PP Globe Valve) opening and closing parts are plug shaped valve disc, sealing surface is flat or conical, valve disc along the center line of the seat for linear movement. Stem movement form, (common name: dark rod), there are also lifting rotary rod type, (common name: bright rod) globe valve refers to the closure of the piece (disc) along the center line of the valve seat movement. According to the moving form of the disc, the change of the valve seat opening is directly proportional to the disc stroke. Due to this kind of valve stem open or close stroke is relatively short, and has a very reliable cut off function, and because of the change of the valve seat opening and the stroke of the disc is directly proportional, very suitable for flow regulation. Therefore, this type of cut-off globe valve is ideal for cut-off or regulation and throttling.

Working principle and characteristics of globe valve: Valve plays an cut off in its line in the medium and the important role of throttle, cut-off valve, as a kind of extremely important truncated class valves, which exert torque on the valve stem seal, valve stem in axial direction to the pressure on the disc, the valve sealing surface and the valve seat sealing surface fit closely, prevent leakage of medium along the gaps between the sealing surface. The sealing pair of globe valve is composed of disc sealing surface and seat sealing surface, and the valve stem drives the disc along the center line of the seat for vertical movement. In the process of opening and closing, the opening height of the globe valve is small, and it is easy to adjust the flow, and it is convenient to manufacture and maintain, and the pressure is widely applicable.

Compared with another commonly used cut-off valve in industrial production - alarm valve, in terms of structure, globe valve is simpler than the former, easy to manufacture and maintenance. From the service life, the globe valve sealing surface is not easy to wear and scratch, valve opening and closing process and no relative sliding between the disc and the sealing surface, so the wear and scratch of the sealing surface is small, so improve the service life of the sealing pair globe valve in the full closing process of the disc travel is small, its height is relatively small alarm valve. The disadvantage of PVDF globe valve is that the opening and closing torque is large and it is difficult to achieve fast 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.

The characteristics of PPH Globe valve: (1) Globe valve structure is simpler than gate valve, manufacturing and maintenance are more convenient.

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

(3) when opening and closing, the disc stroke is small, so the globe valve height is smaller than the gate valve, but the structure length is longer than the gate valve.

(4) the opening and closing torque is large, the opening and closing is more laborious, and the opening and closing time is principal.

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

(6) Medium flow direction nominal pressure PN≤16MPa, the general use of downstream, medium from the lower direction of the valve disc; Nominal pressure PN≥20MPa, the general use of countercurrent, medium flow from the direction of the disc. To increase the sealing energy. When used, the globe valve medium can only flow in one direction, can not change the direction of flow.

(7) When fully open, the disc is often eroded.

Stem axis of globe valve is perpendicular to sealing surface of valve seat. Stem opening and closing stroke is relatively short and has very reliable cutting action, making this valve suitable for medium cutting or regulating and throttling use.

Using the advantages: 1, double sealing design (bellows + packing) if the bellows fail, stem packing will also avoid;

2, external leakage, and in line with international sealing standards;

3, no fluid loss, reduce energy loss, improve the safety of factory equipment;

4, long service life, reduce the number of maintenance, reduce operating costs;

5, strong and durable bellows seal design, to ensure the stem of zero leakage, provide no maintenance conditions.

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Author:

Mr. Zheng

E-mail:

zheng@rmiplast.com