The failure of the over-pressure secondary intake valve caused by the failure of the secondary intake valve also causes the valve to leak and is leaked. In the case of heavy trucks, the inhalation process is normal. During the compression and exhaust process, once the pressure in the cylinder is higher than the first-stage pressure, the gas in the cylinder leaks into the first-stage exhaust chamber through the fault point of the intake valve. This causes the gas to accumulate and overpressure. In another case, the intake valve pressure fork should not be pressed to the intake valve plate under heavy vehicle conditions. If the secondary intake valve pressure opening device is improperly adjusted, the pressure fork always puts the valve of the individual valve or all the valves. Partially or completely open, so that the second stage is in a partially or completely empty state, and at this time, the first stage is working in the normal heavy truck, which will inevitably cause the first stage pressure overpressure. When the vehicle is empty, since the intake valve is fully opened (normally open) by the pressing device, even if the secondary intake valve leaks, it cannot be reflected. Therefore, when the heavy vehicle is overpressured, the fault is in the secondary intake valve.

When the rack piece is soldered and assembled, the center line position is marked and marked. In order to understand the shrinkage after welding and heat treatment. Use a slab to control its angular deformation. After the 6mm round steel, the process lacing and the Π-shaped plate are welded, the welding of the frame piece is performed. First weld one side of the weld, then turn the rack piece over and clear the root with a gouging. Weld the weld on the other side and weld it with J507, 4mm, 5mm welding rod. The welding current specification parameters are selected and the low current interval is applied. After all welds have been welded, the end of the weld is cleaned with a gouging. After cleaning, seal the ends and smooth them. The dimensions of each part are measured after cooling to room temperature after welding, and the measurement results meet the requirements of drawings and process technology.

Post-weld heat treatment is performed after annealing to eliminate stress treatment. After the heat treatment, the process lacing and the slab are removed, and the weld is smoothed. After ultrasonic and magnetic particle inspection of the weld bead, ultrasonic and magnetic particle inspection were carried out according to JB1152-81II standard. No flaws were found in the inspection results, and the weld quality was fully qualified. Assembling and welding technology requires that the dimensions of the parts that make up the frame are not in accordance with the drawings and process requirements; the assembly and measurement of each part size and assembly position are first performed, and the assembly must not be forcibly assembled; The 50mm steel plate shall be preheated at 50 ~ 100 °C for welding. It shall be welded by gas shielded welding. The difficult welding part shall be manually arc welded. When the assembly gap is enlarged during the welding process, the welding shall be stopped, and measures shall be taken to meet the process requirements before welding; In order to facilitate the welding, the 9 component parts are first welded.

Assembly welding and correction of components to facilitate welding, some parts are pre-packed separately; after component assembly, spot welding, welding, individual deformation, with flame or press leveling, after measurement meets the technical requirements. Assembly and welding of the rack Place the spacers on the platform to facilitate assembly of the components. The welding position line is drawn based on the rack piece. Install the parts that are attached to the rack plate in order. The assembly sequence is based on the principle of facilitating the welding and deformation of the weld. After the point is solid, the welding is performed. When welding, the groove is deep and the welding meat is large. In order to reduce the deformation, weld the weld to 1/3 1/2 and then weld the other parts.

Pay attention to the symmetry of the two sides when welding, so as to minimize the deformation caused by welding. Use the necessary process lacing (channel steel, etc.) to control the amount of deformation. The welds that are connected to the rack piece should be welded over 1/3~1/2 and cannot be welded to avoid excessive welding stress and large welding deformation. Small welds can be welded in place at one time. Layered welding is used to control the amount of deformation. After the above-mentioned weldment is turned over, the welding of the frame piece to the remaining part of the peripheral weld is completed. On this basis, turn over again, and weld the joint with the rack piece and continue to weld the remaining parts on the side. After turning over again, the remaining parts are welded and all welds are welded.

Conclusion The quality of the stock before welding is directly affected by the final quality of the weldment. Therefore, it is necessary to pay attention to it, and a single piece that has been qualified for loading can be welded. For larger welded structural parts such as coiler frames, weld distortion is difficult to correct. Therefore, the use of rigid fixation is the main means to ensure the quality of the weldment. Due to the large size of the weld, layered welding must be used to control the thermal stress and deformation. The welding of the main process lacing and support shall be completed by a certified welder to ensure the quality of the weld and obtain the desired control effect.

BS Flanges

In strict accordance with ISO 9001:20015 and BS Flanges;
1.Make process card and quality plan
2.Choose the qualified raw material and do incoming test, not allowed
nonconforming material to enter into production process;
3.Producing and testing followed the quality documents
4.Be good at Quality records and product identification to ensure the product
traceability
5.Do the final inspection to ensure 100% of pass.

Bs Flange,900Lbs Flange,1500Lbs Flange,2500Lbs Flange

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