Structure and Advantages of the Check Valve

The closing element of a shut-off valve is a plug-shaped valve disc, with sealing surfaces that are either flat or conical. The valve disc moves in a straight line along the centerline of the fluid. The motion of the valve stem can be either lifting and lowering (the stem rises and lowers while the handwheel does not) or lifting and rotating (the handwheel rotates and rises or lowers along with the stem, with the nut set on the valve body).

Check ValveValves of this type are of the forced-sealed design, which requires pressure to be applied to the valve disc when closed to ensure a tight seal. As the medium enters the valve six from below the valve disc, the resistance that the operating force must overcome includes the friction between the valve stem and the packing material, as well as the thrust generated by the pressure of the medium. The force required to close the valve is greater than the force to open it, necessitating a larger diameter of the valve stem to prevent bending. In recent years, with the advent of self-sealing valves, the flow direction of the medium in globe valves has changed to entering the valve cavity from above the valve disc. Under the pressure of the medium, the force required to close the valve is reduced, while the force to open it is increased, allowing for a reduction in the diameter of the valve stem. Additionally, under the action of the medium, this type of valve is also more airtight. China's valves...“Three Dimensions Co.”It was previously stipulated that the direction of flow for check valves should always be from top to bottom.

Stop valves are categorized by the position of the valve stem thread into external threaded and internal threaded types. By the direction of medium flow, they are divided into straight-through, direct-acting, and angle types. According to the sealing form, stop valves include stuffing box sealed stop valves and bellows sealed stop valves.

Valve Installation and Maintenance

The handwheel and handle-operated needle valves can be installed at any position on the pipeline.

Handwheels, handles, and power-driven mechanisms are not to be used for lifting purposes.

The flow of the medium should be in the same direction as the arrow indicated on the valve body.

At the opening of the shut-off valve, the lift height of the valve disc is equal to the nominal diameter.25%～30%At this point, the flow has reached its maximum, indicating that the valve is fully open. Therefore, the fully open position of the shut-off valve should be determined by the stroke of the valve disc.

The shut-off valve boasts the following advantages:

1Simple structure, easy to manufacture and maintain.

2Our work schedule is compact, with shorter opening and closing times.

3Sealed well, with minimal friction between sealing surfaces, resulting in a longer lifespan.

The disadvantages of the shut-off valve are as follows:

1High fluid resistance, requiring significant force for opening and closing.

2Not suitable for media with granules, high viscosity, and a tendency to clog.

3Performance adjustment is subpar.

The types of stop valves are categorized by the position of the valve stem thread into external threaded and internal threaded. According to the flow direction of the medium, they are divided into straight-through, direct-acting, and angle types. In terms of sealing form, stop valves are classified into glanded seal stop valves and bellows seal stop valves.

Valve Installation and Precautions:

1Quarter-turn and lever-operated shut-off valves can be installed at any location on the pipeline.

2Wheels, handles, and伟动机构are not permitted for lifting purposes.

3The direction of the medium flow should be consistent with the arrow direction indicated on the valve body.

Characteristics of the shut-off valve structure:

1. The valve's cavity utilizes a pressure self-tightening sealing structure, with superior sealing performance..

2. The sealing surfaces of the valve disc and seat are spray-welded with Stellite cobalt-based hard alloy.,Abrasive-resistant, heat-resistant, corrosion-resistant, scratch-resistant, excellent performance.

3. High-Temperature Creep-Resistant Design.

4. The valve rod is made with an integrated forging structure.,Heat treated and surface-nitrided,Excellent corrosion and abrasion resistance.

5. Valve cover stuffing box depth is reasonably designed.,Filling Material with Corrosion Inhibitor,Sealed and Reliable.

For pipelines carrying water, metallurgical fluids, steam, oil products, and superheated steam in power plants, petrochemicals, and metallurgy industries, cutting off or connecting media.