Cast Steel Flange Lifting Check Valve H44H

H44H-PN16~PN64 cast steel flange lift check valve. When the medium flows into the valve body as indicated by the arrow on the valve body, the pressure of the medium acts on the valve disc to generate an upward thrust. When the medium thrust is greater than the gravity of the valve disc, the valve opens. When the force exerted by the pressure of the medium behind the valve on the valve disc plus the gravity of the valve disc itself is greater than the force exerted by the pressure before the valve on the valve disc, the valve closes to prevent the medium from flowing back.

Check valve is one of the important links in the production process regulation system, which is a valve type product that controls the one-way flow direction of the medium in the pipeline and prevents the back flow of the medium. Strictly designed and manufactured according to GB12235 standard, the valve disc moves up and down along the center positioning, and the lining is made of special materials with good wear resistance and low friction coefficient, making it flexible and reliable in operation Excellent sealing performance. H41H/H41W/H41F flange lifting stainless steel check valves are widely used in pipelines in various working conditions such as petroleum, chemical, pharmaceutical, and power industries. It has the advantages of simple structure, reliable operation, and convenient maintenance.

 

Product features:

1) The selection of materials is meticulous, in accordance with relevant domestic and foreign standards, and the overall quality of the materials is high.

2) The lifting check valve is the type of check valve with the best back flow sealing effect among all types of check valves.

3) The product is designed and manufactured according to the national standard GB/T12235.

4) Various piping flange standards and flange sealing types can be used to meet various engineering needs and user requirements.

5) The valve body material variety is complete, and the 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.

 

Execution standards:

Design and manufacturing: GB/T12235

Structural length: GB/T12221

Flange standard: JB/T79

Inspection and testing: JB/T9092

Logo: GB/T12220

Supply goods: JB/T7928

 

Operation of check valve:

The operation of check valves should avoid the following situations:

1) Excessive impact pressure caused by the closure of the check valve.

2) The valve closing component quickly oscillates.

To avoid excessive shock pressure caused by closing the check valve, the valve must close quickly. To prevent the formation of excessive back flow velocity. The back flow velocity is the reason for the formation of shock pressure, so the closing speed of the check valve should be correctly matched with the attenuation velocity of the downstream medium.

However, the attenuation rate of the downstream medium may vary greatly in liquid systems. For example, if a liquid system uses a set of parallel pumps and one of them suddenly fails, the check valve at the outlet of the failed pump must be closed almost simultaneously. In addition, if there is only one pump in the liquid system and this pump suddenly fails, such as if the delivery pipe is long and the back pressure and pumping head at the outlet end are low, it is better to close the check valve with a smaller speed.

If the moving parts of the check valve wear out too quickly, it can lead to premature failure of the valve. To prevent this situation from happening, it is necessary to avoid the rapid oscillation action of the closing component. This rapid oscillation action of the closing component can be avoided by selecting a valve that forces the closing component to stably respond to the medium velocity that stops flowing.

This ideal situation is not often obtainable. For example, if the velocity variation range of the downstream medium is large. The minimum flow rate is not enough to force the closing component to stop steadily. In this case, the movement of the closing member can be within a certain range of its movement stroke

Use dampers inside the enclosure to suppress it. If the medium is pulsating flow, the check valve should be placed as far away from the pulsating source as possible. The rapid oscillation of the closing component may also be caused by extreme medium disturbance. In cases where this occurs, check valves should be installed.In the place where the disturbance of the medium is minimal.

Therefore, the first step in choosing a check valve is to understand the operating conditions under which the check valve is located.

 

Installation precautions for check valves:

The installation of check valves should pay attention to the following matters:

1) Do not let the check valve bear weight in the pipeline. Large check valves should be supported independently to prevent them from being affected by the pressure generated by the pipeline system.

2) During installation, pay attention to the direction of medium flow, which should be consistent with the arrow direction indicated on the valve body.

3) Lift type vertical disc check valves should be installed on vertical pipelines.

4) The lifting type horizontal disc check valve should be installed on the horizontal pipeline.