Power station flange globe valve

J41HPower station flange globe valveProduct Description

This utility model relates to a novel flange type power station cut-off valve body, which belongs to various technical fields of general mechanical equipment The current new type of power station cut-off valve body is composed of two components, the valve body inlet and outlet, and the sealing surface, which are welded together This technology ensures the machining accuracy of the sealing surface of the power station cut-off valve body, but it is not convenient for future maintenance of the sealing surface of the power station cut-off valve body The newly designed new flange type power station cut-off valve body is composed of two components: the valve body inlet and outlet, and the sealing surface, which are connected by flange connection This technology not only ensures the machining accuracy of the sealing surface of the power station cut-off valve body, but also solves the problem of repairing the sealing surface of the power station cut-off valve body in the future. It belongs to the forced sealing type 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 valve six from below the valve disc, the resistance that the operating force needs to overcome is the frictional force between the valve stem and the packing, as well as the thrust generated by the pressure of the medium. The force required to close the valve is greater than the force required to open it, so the diameter of the valve stem should be larger, otherwise the valve stem will bend due to failure.

The opening and closing component of a stop valve (Globe Valve) is a plug shaped valve disc, with a sealing surface that is flat or conical. The valve disc moves linearly along the centerline of the fluid. The movement form of the valve stem includes a lifting rod type (the valve stem is lifted and lowered without the handwheel lifting), as well as a lifting rotating rod type (the handwheel rotates and lifts together with the valve stem, and the nut is set on the valve body). Globe valves are only suitable for fully open and fully closed, and are not allowed to be adjusted or throttled.

Globe valves belong to forced sealing valves, 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 below the valve disc, the resistance that the operating force needs to overcome is the frictional force between the valve stem and the packing, as well as the thrust generated by the pressure of the medium. The force required to close the valve is greater than the force required to open it, so the diameter of the valve stem should be larger, otherwise the valve stem bending fault may occur. In recent years, with the emergence of self sealing valves, the flow of medium in shut-off valves has shifted from above the valve disc into the valve chamber. Under the pressure of the medium, the force required to close the valve is small, while the force required to open the valve is large, resulting in a corresponding reduction in the diameter of the valve stem. Meanwhile, under the influence of the medium, this type of valve is also relatively tight. The "Three Modernizations" of valves in our country once stipulated that the flow direction of globe valves should be from top to bottom.

When the shut-off valve is opened and the opening height of the valve disc is 25% to 30% of the nominal diameter, the flow rate has reached its maximum, indicating that the valve has reached the fully open position. So the fully open position of the shut-off valve should be determined by the stroke of the valve disc.

■ J41HPower station flange globe valveStructural features:

1. The material selection of the flange globe valve is exquisite, in line with relevant domestic and foreign standards, with a reasonable structure and beautiful appearance.

2. The sealing surface of the flange globe valve disc and seat is made of iron-based alloy welding or Stellite cobalt based hard alloy welding, which has good wear resistance, high temperature resistance, corrosion resistance, abrasion resistance, and long service life.

4. The valve stem of the flange globe valve has undergone quenching and surface nitriding treatment, and has good corrosion resistance and abrasion resistance.

5. Flange globe valves can adopt various piping flange standards and flange sealing surface types to meet various engineering needs and user requirements.

6. The valve body materials of the flange globe valve are complete, and the packing and gasket can be reasonably selected according to actual working conditions or user requirements, which can be suitable for various pressure, temperature, and medium working conditions.

7. The reverse seal of the flange globe valve is made of threaded connection sealing seat or welded austenitic stainless steel body, which is reliable in sealing. The replacement of packing can be carried out without stopping the machine, which is convenient and fast, and does not affect the operation of the system.

J41HPower station flange globe valveParts material

Note: 1. Forged steel globe valves can also be used for other materials required by customers. The matching of sealing fabrics is determined by the customer's internal part code.

2. CS=Carbon Steel; AS=alloy steel; SS=stainless steel;

150～600LB

NPS

900～1500LB

Specifications, dimensions, and weight (mm)

Technical requirements and precautions for the installation of globe valves

（1） Installation technical requirements
(1) During the transportation and installation process, the transmission device of the valve cannot be used as a lifting point.
(2) Carefully inspect the quality of flanges, bolts, and pads during installation, and there should be no defects such as burrs, unevenness, cracks, etc.
(3) During the installation process, check the installation of flanges and pipes, and there should be no misalignment, wrong holes, open mouth, deviation, or other phenomena.
(4) The flange sealing surface must be cleaned thoroughly during installation, and bolts and gaskets should not be contaminated with impurities.
(5) The cushion should be concentric with the pipe or fitting.
(6) When tightening the bolts, apply even force and tighten them symmetrically.
(7) Before installation, suitable sealing gaskets and bolts should be selected according to the operating conditions.
（2） Precautions
(1) Globe valves are only used to cut off or connect the medium in pipelines, and should not be used to regulate the pressure or flow of the medium. If used for long-term adjustment, the sealing surface will be eroded by the medium, and its sealing performance cannot be guaranteed. The parts that often need to adjust pressure or flow should be equipped with throttle valves or regulating valves.
(2) Straight through or direct flow globe valves should be installed in horizontal pipelines. Cut off valves with good valve disc neutrality can also be installed in vertical pipelines. Angle globe valves are installed at the turning points of vertically intersecting pipelines.
(3) During installation, it should be ensured that the flow direction of the medium is consistent with the arrow shown on the valve body (the medium should be low in and high out of the valve body, and cannot be installed in reverse). The valve chamber of the globe valve is asymmetric on both sides. It is necessary to allow fluid to pass through the valve port from bottom to top, so that the fluid resistance is small (determined by its shape), and opening is effortless (due to the upward pressure of the medium). After closing, the medium is pressurized and filled, making maintenance easier. This is the reason why globe valves cannot be installed in reverse.

Ordering Notice:

1、 ① Product name and model ② Caliber ③ Is there any accessory for us to correctly select for you ④ Operating pressure ⑤ Temperature of the medium used.
2、 If the company's model has already been selected by the design unit, please order directly from our sales department according to the model.

3、 When the usage situation is very important or the environment is complex, please provide design drawings and detailed parameters as much as possible, and our valve company experts will review and control them for you. If you have any questions: Please: We will do our best to provide you with high-quality service. We provide comprehensive and professional "valve system solutions" and are also willing to help users solve problems encountered in production.