1.Overview
Butterfly type microresistance slow closing check valve (WZHF) is mainly used in water conservancy, electric power, water supply and drainage, municipal engineering, petroleum, petrochemical, metallurgy and other industries. It can effectively eliminate the water hammer in the pipeline and realize the reliable check of the pipeline so as to protect the pipeline system.
2.How it works?
When the water pump is started, the check valve will open automatically under the action of water pressure, the heavy hammer will lift up. The check valve will slowly open to the maximum opening. When the water pump is running, the check valve will work stably at a large opening. When the pump stops normally or in case of accident, the check valve is automatically closed in two stages: fast stage and slow stage.
Fast closing stage: under the action of dead weight moment, weight hammer moment and backflow water, the check valve plate quickly closes the valve about 75% - 85% of the angular travel, and cuts off a large amount of backflow water.
Slow closing stage: after the fast closing stage, the hydraulic oil circulating in the oil cylinder is throttled by the throttling element set in the oil cylinder of the slow closing device to produce damping, and the slow closing performance is good.
3.Structural features
Butterfly type structure, short length and light weight.
The valve plate is inclined and double offset, and the opening and closing movement of the valve is reasonable.
Wear resistant rubber soft seal or all metal seal can be used.
The slow closing device is completely separated from the medium with reliable performance.
Large diameter products are equipped with double oil cylinders to make valve closing more safe and reliable.
In order to ensure that the check valve can be sealed when the return water pressure is too low, the adjustment hole is set on the heavy hammer arm. And the weight hammer is placed outward, which can increase the specific pressure between the check valve sealing surfaces so as to ensure the valve sealing effect. If the system return water pressure can fully meet the valve sealing requirements, the weight can be adjusted inward to minimize the system pressure loss.
4. Main standards and specifications
CJ/T 282 butterfly slow closing check valve
GB/T 12221 structural length of metal valves
GB/T 9113 integral steel pipe flange
GB/T 17241.6 integral cast iron pipe flange
GB/T 13927 pressure test for industrial valves
GB/T 700 carbon structural steel
GB/T 12227 specification for ductile iron castings for general purpose valves
GB/T 12229 specification for carbon steel castings for general purpose valves
Butterfly type microresistance slow closing check valve (WZHF) is mainly used in water conservancy, electric power, water supply and drainage, municipal engineering, petroleum, petrochemical, metallurgy and other industries. It can effectively eliminate the water hammer in the pipeline and realize the reliable check of the pipeline so as to protect the pipeline system.
2.How it works?
When the water pump is started, the check valve will open automatically under the action of water pressure, the heavy hammer will lift up. The check valve will slowly open to the maximum opening. When the water pump is running, the check valve will work stably at a large opening. When the pump stops normally or in case of accident, the check valve is automatically closed in two stages: fast stage and slow stage.
Fast closing stage: under the action of dead weight moment, weight hammer moment and backflow water, the check valve plate quickly closes the valve about 75% - 85% of the angular travel, and cuts off a large amount of backflow water.
Slow closing stage: after the fast closing stage, the hydraulic oil circulating in the oil cylinder is throttled by the throttling element set in the oil cylinder of the slow closing device to produce damping, and the slow closing performance is good.
3.Structural features
Butterfly type structure, short length and light weight.
The valve plate is inclined and double offset, and the opening and closing movement of the valve is reasonable.
Wear resistant rubber soft seal or all metal seal can be used.
The slow closing device is completely separated from the medium with reliable performance.
Large diameter products are equipped with double oil cylinders to make valve closing more safe and reliable.
In order to ensure that the check valve can be sealed when the return water pressure is too low, the adjustment hole is set on the heavy hammer arm. And the weight hammer is placed outward, which can increase the specific pressure between the check valve sealing surfaces so as to ensure the valve sealing effect. If the system return water pressure can fully meet the valve sealing requirements, the weight can be adjusted inward to minimize the system pressure loss.
4. Main standards and specifications
CJ/T 282 butterfly slow closing check valve
GB/T 12221 structural length of metal valves
GB/T 9113 integral steel pipe flange
GB/T 17241.6 integral cast iron pipe flange
GB/T 13927 pressure test for industrial valves
GB/T 700 carbon structural steel
GB/T 12227 specification for ductile iron castings for general purpose valves
GB/T 12229 specification for carbon steel castings for general purpose valves
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