With the adjustment and development of urban construction, various types of cables and pipelines buried under the road have gradually increased and are difficult to arrange. The traditional installation method of the pipe network valve is placed in the valve well on the road. When the well cover is impacted by rolling, noise will be generated. The top of the valve display can not be flush with the road surface, which will affect the bumpy operation of the traffic vehicles and affect the urban landscape. The repeated occurrence of well covers will also result in personal injury and death, vehicle damage and other safety accidents. The adoption of direct-buried installation can avoid the above problems and save investment.
In foreign industrialized countries, pipe network valves have long been used in direct burial. All gate valves that meet the requirements of the standard can be directly buried without valve wells.
The direct-buried valve can be directly buried underground, and it is not necessary to build a well and reduce the area of road surface excavation. The extremely small well room can keep the appearance of the road, reduce the construction difficulty, and save the construction cost. The direct-buried soft-sealed gate valve is divided into two types: telescopic type and fine-tuned fixed type, in which the retractable type is divided into metal type plastic type.
During the construction process, the telescopic type can be arbitrarily adjusted according to the distance between the buried depth of the valve and the ground, and the micro-adjustable fixed type can be used for on-site micro adjustment.
The direct-buried valve has small flow resistance, the media channel inside the valve body is straight, the medium is in a straight line, and the flow resistance is small. In addition, the opening and closing of the more dynamic, compared with the cut-off valve, whether it is open or closed, the direction of movement of the gate and the media flow direction is perpendicular.
The old residential community has a poor living environment, a large population of residents, and relatively complete supporting facilities. At the same time, the use of gas points is rather chaotic. The transformation of gas pipeline networks has a greater impact on residents' travel and daily use of natural gas. In order to ensure the safety of indoor air supply, to prevent the gas inlet valve from being installed in the resident's user's room, and to prevent the emergency closing of the valve, the residential house gas inlet valve should be installed outside the building. There are two ways: First, The outdoor valve protection box is set when the ground is introduced; second, the direct-buried valve is set when the underground floor is introduced.
When a residential building does not have the conditions to set up an outdoor valve protection box, a buried valve can be installed on the buried pipe before the construction as the inlet valve. The direct-buried valve should have good anti-corrosion performance, the service life should not be lower than the service life of the gas pipeline, and it should have the function of maintenance-free during the life cycle. Its supporting well application has anti-theft function. The adoption of direct-buried valves can optimize the management of gas operation management units to users and enhance the ability to handle emergencies.