Globe Valve

A globe valve is a linear flow valve used to stop, start, and regulate flow. Unlike ball valves, the medium in a globe valve does not flow directly in one direction. Instead, it enters the valve body, rises upward, and exits from the opposite end. The valve closes via a disc that is screwed into the seat using a handwheel or actuator. Rotating the handle causes the disc to descend or ascend. When fully lowered, water supply is shut off. When fully raised, flow reaches maximum velocity.

The most common application for globe valves is standard faucets, widely used in industrial piping systems.

Key Features of globe valves

- Wide range of body materials including cast iron, ductile iron, and stainless steel

- Flanged and threaded valve designs

Suitable for diverse applications and media based on product type, maintenance-free

Cold/hot water, steam, nitrogen oxides, gases, air, oil, chemicals, and various acids

Unlike gate valves, globe valves can regulate flow or pressure as well as completely shut off flow. Compared to gate or ball valves, globe valves exhibit significantly higher pressure loss at fully open positions. This occurs because the fluid changes direction as it passes through the valve.

A key characteristic of globe valves is that the seat is parallel to the flow line. This feature enables efficient throttling while minimizing wear on the disc and seat.

Coating:

             1).Fusion   Bonded Epoxy Powder Coating

             2).Akzo   Nobel Powder Coatings

A stop valve is a type of valve that controls the flow of medium by moving the disc along the centerline of the valve seat. Due to its simple structure, good sealing performance, and excellent regulating performance, it is widely used in various industrial and civil pipeline systems.

I. Core Advantage: Why Choose a Stop Valve?

Reliable sealing performance

The disc and seat of the stop valve adopt a "face-to-face" linear sealing structure. When closed, the disc closely adheres to the seat, effectively blocking the flow of the medium, and the leakage rate is much lower than that of other types of valves, such as gate valves. Especially under low-pressure conditions, even after long-term use, the wear on the sealing surface is relatively small, and it can maintain a stable sealing effect, making it suitable for systems that are sensitive to leakage.

Outstanding regulating performance

The lifting stroke of the valve disc has an approximately linear relationship with the flow rate. By controlling the opening degree of the valve disc, the flow rate of the medium can be precisely regulated. Therefore, it is often used in scenarios that require flow control, such as temperature regulation in heating systems and medium ratio control in chemical processes.

It has a wide range of applicable media.

Different materials of valve bodies and sealing surfaces can be selected according to the characteristics of the medium.

Cast iron or ductile iron valve bodies are suitable for neutral media such as water and steam.

The cast steel or stainless steel valve body can withstand high temperatures, high pressures, and slightly corrosive media.

When the disc and seat adopt metal-to-metal sealing, it can be used in high-temperature and high-pressure systems. When rubber or PTFE seals are used, they are suitable for low-temperature, corrosive, or clean media.

Ii. Structural Features: How to Achieve Efficient Work?

The typical structure of a stop valve consists of a valve body, valve cover, valve disc, valve stem, handwheel, or drive device. Its core design features determine its working performance:

Flow channel design: When the medium flows in from below the valve seat, it needs to make a "right-angle turn" before flowing out, resulting in relatively high flow resistance. This feature also increases the sealing force when the valve is closed. The medium pressure pushes the valve disc toward the valve seat, which further improves the sealing performance. 

Common forms of valve discs include flat top, plunger, and needle types. Flat-top valve discs are suitable for general shut-off scenarios. Needle disc valves are often used for precise control of small flow rates due to their small sealing surface and high regulating accuracy.

Drive mode: In addition to manual handwheels, it can also be equipped with electric, pneumatic, or hydraulic drive devices to achieve remote automatic control and meet the centralized regulation requirements of large industrial systems.

Iii. Applicable Scenarios: In which working conditions are stop valves more suitable?

High-pressure or high-sealing requirements occur

For instance, in the petrochemical industry, for oil transportation pipelines, gas pipelines, high-pressure steam pipelines, etc., the tight sealing of stop valves can effectively prevent the leakage of flammable, explosive, or toxic media, ensuring the safety of the system.

Small-diameter pipelines or intermittent operation scenarios

The small-diameter (DN15~DN100) stop valve features a compact structure and flexible operation, making it suitable for water supply pipelines and fire protection pipelines. At the same time, because of its reliable sealing when closed, it is also often used in situations where frequent opening and closing are required.

Iv. Precautions for Use

Installation direction: The valve should be installed according to the flow direction indicated on the valve body, which is typically labeled as "low in and high out." If the valve is installed incorrectly, with the flow reversed, it may cause the valve disc to have difficulty closing due to the pressure of the medium, resulting in a decline in sealing performance.

Maintenance Cycle: Regularly inspect the valve stem packing. If you notice any leakage of the medium, be sure to replace the packing promptly. If there are scratches on the sealing surface, they can be repaired by grinding to extend the service life.

Avoid using beyond operating conditions: Different materials of stop valves have clear temperature and pressure limits. Using them beyond these limits can lead to deformation of the valve body or failure of the seal.

To sum up, the stop valve, with its reliable sealing performance and precise regulating capacity, has become a key device for controlling the flow of media in pipeline systems. Especially in scenarios where both shut-off and regulating functions need to be taken into account, it demonstrates irreplaceable advantages.