Electric straight-through globe valve maintenance process and processing technology valve knowledge sharing: Electric continuous high temperature globe valve common problems
The closing of the globe valve is through the working pressure of the stem, so that the valve head and the seat are pressed closely to complete the sealing. Its application scope is closed, can also roughly adjust the valve, but do not use as a relief valve. The globe valve generally has straight through type, Angle type or DC type three. Direct stop valve, Angle type stop valve, DC type stop valve.
1. Principle of globe valve
The closing of the globe valve is through the working pressure of the stem, so that the valve head and the seat are pressed closely to complete the sealing.
2, the main purpose of the globe valve
Its application scope is closed, can also roughly adjust the valve, but do not use as a relief valve. Stop valves are used very much in power stations, especially in relatively small safe passages, when good closing tightness is provided, most of these gate valves are used.
Its advantages are: compact structure, compact structure, manufacturing, convenient maintenance.
Main disadvantages: flow resistance, opening and closing force is relatively large, but with the increase of channel section and rapidly increase. Therefore, it is very difficult to make a reliable stop valve with a large channel section.
3. Classification of globe valve
The globe valve generally has straight through type, Angle type or DC type three.
(1) direct stop valve. Direct stop valve stem and medium channel axis at 90 Angle, this kind of stop valve is widely used in power plants. As shown in Figure 2-2.
(2) Angle type stop valve. The feature of the Angle globe valve is that the medium in the valve and the original inflow into 90, as shown in Figure 2-3.
(3) direct current type stop valve. Dc stop valve is a valve stem and medium channel axis of the Angle of view, as shown in Figure 2-4.
4. Structure characteristics and maintenance processing technology of electric straight-through globe valve
Following the electric straight-through globe valve as an example, a brief introduction to the structural characteristics of the globe valve and maintenance processing technology.
(1) Electric straight-through globe valve structure.
Electric straight-through globe valve connection for socket welding, gate valve support frame and valve seat flange connection, door rod and valve seat sealing, from inside to outside, the use of the first with the spare cap and valve seat flange connection, the top cover gasket, and then is the filling material, is the root screw cap, sealing performance is reliable. As shown in Figure 2-2.
(2) Maintenance and processing technology of electric straight-through globe valve.
1) The electric straight-through stop valve collapses.
① After the completion of the work ticket, ensure that there is no water in the pipeline, no pressure, you can start; (2) Prepare helpers and other safety equipment in advance, build a steel pipe scaffold, lifting point, contact the power distribution equipment staff to remove the power plug; (3) After manually opening the 1-2 buttons of the gate valve, lift the electric tissue with guide chain and galvanized steel wire rope, disassemble and install the electric mechanism and support frame, tighten the bolts, and withdraw the electric tissue smoothly and lift it up; (4) Remove the anchor bolt of gate valve marking roller and take out the shaft hole for safekeeping; ⑤ Turn the support frame counterclockwise to withdraw and lift it up; (6) Disassemble and install the fastening screw of the disc cap, take out the disc cap, dig out the filling material; ⑦ With special tools, the spare cap back, pull out the door stem and valve head, the valve seal.
2) Maintenance of electric straight-through stop valve.
(1) Check the valve seat and valve head surface, should be smooth, no abrasion, groove marks, black spots and other shortcomings, if there is, should be carried out grinding treatment according to the shortcomings level or repair grinding.
(2) Check the valve stem, no bending, damage, abrasion and other shortcomings. And the rotary seal, should be clean, no groove marks and other shortcomings, the screw in the valve stem has no damage, and the nut with good coordination, easy rotation, otherwise should be repaired. The stem should be bent within 0.1mm, and the depth of the wear pit should not exceed 0.1-0.2mm.
③ The gap between the valve stem and the spare cap should be measured accurately within the range of 0.2~0.25mm, and the gap between the valve seat and the disc cap should be within the range of 0.2~0.3mm.
(4) Check the connection screw between the support frame and the seat, there should be no damage, and the mutual coordination is good. Each fastening screw should be well matched with the screw cap.
The wear degree of the nut screw shall not exceed 1/3 of the length of the wire.
Check the transmission device, gear, rack wear, the damage should not exceed 1/3 of the tooth thickness, tooth integration part should not crack and tooth safety risks. Check whether the rolling bearing is damaged and rotates insensitively. Manual and automatic selection is easy and reliable, and the transmission system is cost-effective.
3) Assembly of electric straight-through stop valve. The assembly process of the electric globe valve is reversed with the disintegration process.
Electric continuous high temperature stop valve can be placed in all positions of the pipeline, the medium from the bottom to the upper stream. Product appearance design and manufacturing according to the national industry standard GB12235, reasonable structure, reliable sealing, excellent performance, beautiful shape. Carbon steel globe valve is suitable for heat-resistant steam and oil pipelines, with heat-resistant characteristics. Electric continuous high temperature globe valve is suitable for all kinds of corrosive medium pipelines, with good corrosion resistance and sufficient compressive strength. Valve body material variety is complete, filling material, gasket can be effectively selected according to the specific working conditions or user requirements, can be suitable for huge pressure, ambient temperature and medium working conditions.
Electric continuous high temperature globe valve main characteristics and main uses
1. The gate valve and the pipeline are welded together.
2, the surface is not easy to damage, chafing, sealing performance is good. Long service life.
3, simple structure, strong opening and closing, relatively small height, convenient maintenance.
4, can be water, steam, product pipeline road, with heat resistance, high pressure resistance.
Electric continuous high temperature stop valve common problems
Electric continuous high temperature stop valve can be placed in all positions of the pipeline, the medium from the bottom to the upper stream. Product appearance design and manufacturing according to the national industry standard GB12235, reasonable structure, reliable sealing, excellent performance, beautiful shape. Carbon steel globe valve is suitable for heat-resistant steam and oil pipelines, with heat-resistant characteristics. Electric continuous high temperature globe valve is suitable for all kinds of corrosive medium pipelines, with good corrosion resistance and sufficient compressive strength.
The characteristics of the electric continuous high temperature globe valve are shown as follows:
① Piston valve and valve seat surface are made of rigid spray welding, resistant to wear, heat resistance, corrosion resistance, abrasion resistance, strong and durable.
② Valve stem material is high frequency quenched steel, high frequency quenched valve stem hardness, wear resistance, abrasion resistance, corrosion resistance.
(3) Because of the environmental temperature, working pressure and other factors, the valve diameter within DN50 oil circuit plate and single flow valve are die forging parts, and the oil circuit plate and single flow valve above DN65 are stainless steel castings.
④ Valve body material variety is complete, filling material, gasket can be effectively selected according to the specific working conditions or user requirements, can be suitable for huge pressure, ambient temperature and medium working conditions.
⑤ Pay attention to the inflow of the medium when assembling the gate valve, and assemble in strict accordance with the direction indicated by the gate valve inflow arrow.
The electric stop valve as far as possible vertical assembly, stem up.
Post time: Mar-10-2023
