expansion joint When the joint structure does not extend out of the bridge deck, fill the expansion gap at the end of the bridge with elastic materials and pave waterproof materials, then pave viscoelastic compliance materials on the bridge deck pavement layer, so that the bridge deck pavement at the expansion joint and the pavement form a continuum asphalt The deformation of concrete, elastoplastic body and other materials can absorb the expansion and contraction of the beam body, and provide a supporting structure for the wheels. The common forms are bridge deck continuity, TST gravel elastoplastic expansion joints, etc.
Butt joint expansion joint: it is an expansion device that bears the wheel load with the elasticity of the expansion body. The materials used for the expansion body are sand , crushed stone and rubber products of various shapes are also used Foam plastic board or synthetic resin The expansion body is always in compression state.
Supporting expansion joint: It is fabricated from steel and can directly bear the wheel load. This expansion device was used for steel bridges before, but now concrete bridges are also used. The steel supported expansion joint device has a wide range of types, status quo and dimensions, and the steel comb type is widely used. The structure of steel comb type bridge expansion joint device is composed of comb plate, connector and anchorage system. Some steel comb type bridge expansion devices are filled with synthetic rubber between the comb teeth to play a waterproof role, and some use special drainage channels to solve drainage problems.
The manual reversing valve is a common control valve, which realizes the fluid switching direction through manual operation, thus controlling the flow and pressure of the system. This article will introduce the structure, working principle, precautions for use and common troubleshooting methods of manual directional valve.
1、 Structure
Manual reversing valve is usually composed of valve body, valve core, handle and spring. There is one inlet and two outlets on the valve body, which are used to connect the system pipeline and the equipment to be controlled. The valve core is a baffle plate with two openings, which can control the flow direction of the fluid. The handle is connected with the valve core through the connecting rod, and the opening state of the valve core can be changed through the operating handle, thus changing the flow direction of the fluid. The spring plays the role of maintaining the position of the valve core. When the handle is loosened, the spring will restore the valve core to its original position.
2、 Operating principle
When the handle is in the closed position, the openings of both openings are small, and the fluid will not flow out through the opening of the valve core. When the handle is rotated to the open position, the opening of the valve core will change, thus changing the flow direction of the fluid. If the opening of the valve core faces the outlet A, the fluid will flow out from the outlet A; if the opening of the valve core faces the outlet B, the fluid will flow out from the outlet B. The fluid flow direction can be flexibly controlled by manually operating the handle.
3、 Precautions
1. Check whether the valve body and valve core are intact before operation to ensure that there is no leakage at the connection.
2. Pay attention to the force during operation, and do not use too much force to avoid damaging the valve core and spring.
3. After the operation, the handle shall be placed in the closed position and the spring shall be released to avoid long-term compression deformation.
4. The manual reversing valve shall be regularly inspected and maintained to ensure its normal operation.
4、 Common troubleshooting methods
1. Insufficient fluid flow: check whether the valve body and pipeline have leakage and whether the valve core is fully opened.
2. Unstable fluid pressure: check whether the spring is deformed or damaged, and whether the opening of the valve core is even.
3. The handle shakes during operation: check whether the connecting rod is loose, and tighten it if necessary.
4. The manual reversing valve cannot be reversed: check whether the valve element is stuck or deformed, and clean or replace it if necessary.
In a word, manual directional valve is an important control valve. Correct use and maintenance can extend its service life and improve the stability and efficiency of the system. Understanding the working principle and precautions of manual directional valve can help us better deal with common faults and ensure the normal operation of the system.
Modular bridge expansion device: it is an expansion device composed of longitudinal beam (profiled steel), cross beam, displacement control box rubber sealing belt and other components. The modular expansion device can increase the number of center beam steel and sealing body according to the actual expansion demand, which can form an expansion device that can meet large displacement, and is generally used for bridges with expansion greater than 80mm.
Bridge expansion joint: it refers to the expansion joint usually set between two beam ends, between beam ends and abutments, or at the hinge position of the bridge to meet the requirements of bridge deck deformation. It is required that the expansion joint shall be able to expand freely, firmly and reliably in both directions parallel to and perpendicular to the bridge axis, and shall be smooth without sudden jump and noise after the vehicle is driven; Prevent rainwater and garbage from infiltrating and blocking; Installation, inspection, maintenance and dirt removal shall be simple and convenient. At the place where expansion joints are set, the railing shall be disconnected from the deck pavement.
The function of bridge expansion joints is to adjust the displacement and connection between superstructure caused by vehicle load and bridge construction materials. Once the expansion device of skew bridge is damaged, it will seriously affect the speed, comfort and safety of driving, and even cause driving safety accidents.
Water stop copper plate is a kind of material with excellent waterproof performance, which has been widely used in industry and construction. This article will introduce the definition, characteristics and application scope of water stop copper plate, and elaborate the installation method and application examples. Finally, it summarizes the importance of water stop copper plate and puts forward suggestions for use and installation.
Water stop copper plate is a kind of waterproof material made of copper alloy. It has the characteristics of high strength, corrosion resistance and long service life. In the industrial and construction fields, the water stop copper plate is mainly used in waterproof projects such as basements, pools and tunnels to ensure the safety and durability of the project.
The use range of water stop copper plate is very wide. In the industrial field, the water stop copper plate can be used in the waterproof engineering of factories, power stations, chemical industry and other industries to prevent corrosion and leakage problems in the production process. In the field of construction, water stop copper plate can be used for waterproofing works of basement, garage, pool and other buildings to improve the service life and safety of buildings
