The failure of valves on residual oil pipeline and oil steam pipeline is mainly due to the coking inside. Although the damage degree and position of these valve parts are different, the failure caused by coking inside the valve accounts for almost 90%. Therefore, the coking inside the valve is quite harmful to these high-temperature pneumatic ball valves on the coking unit. During the operation of the device, the failure of the valve shall be checked online at any time and a preliminary judgment shall be made.

Analysis of product characteristics of non-metallic compensator
Characteristics of non-metallic compensator:
⑴ It can compensate multi-dimensional direction. Various ways, large compensation amount and long service life;
⑵ It can effectively compensate or eliminate the device error;
⑶ Low rigidity and small elastic reaction force;
⑷ High temperature range and good corrosion resistance;
⑸ It can effectively isolate vibration and reduce noise;
Use of non-metallic compensator
It is widely used in iron and steel plants, smelters, petrochemical plants, thermal power plants, cement plants, atomic power plants and other equipment such as flue gas desulfurization, dust removal equipment, air heating, flow assist blower and other equipment at the entrance and exit. It is much better than metal compensators, so it is deeply criticized by users and vigorously promoted.
The thrust free compensator applies Pascal theory in fluid mechanics and ingeniously applies a dense annular steam chamber in design structure. This steam chamber has two annular pressure surfaces, one is the fixed end face of the steam chamber, and the other is the annular surface of the shoulder of the expansion tube sealed in the steam chamber, which can be moved with the expansion tube. The area of the movable annular pressure surface is exactly the same as the cross sectional area of the expansion pipe. When the compensator works, under the action of the medium pressure, the pressure on the annular surface is equal to the pressure on the cross sectional area of the expansion pipe, but the direction is opposite, so the two pressures cancel each other. In this way, only the friction force between the compensator and the packing is considered in the design of the support, and the thrust on the fixed support caused by the pressure of the working medium is not calculated in the calculation of the thrust on the fixed support. Therefore, the fixed support is a load reducing support, which can save a lot of support information, as well as human and financial resources.
Device request
(1) When the wall thickness of the pipe section welded to both ends of the compensator is ≥ 6mm, the groove treatment must be stopped, and the hydraulic leak detection test must be stopped as required after welding.
(2) The sliding support and the fixed support are based on the design device and ZTWB type. Except that the thrust of the working pressure of the medium is not calculated, the others are the same. In order to ensure that the pipeline does not have lateral displacement, but expands and contracts along the axial direction, guide sliding supports should be installed at both ends of the compensator, and fixed supports must be installed at the turning of the pipeline.
(3) The thermal insulation protection structure of the compensator is the same as that of the pipeline, but there is no binding force on the expansion part of the expansion pipe.
(4) Under various ambient temperatures, the compensator can stop the device according to the maximum device length LMax, without stretching or tightening. Understand the characteristics of the packing type compensator and the cause of its damage
1. During the pipeline operation, the sliding sleeve of the compensator is strictly subject to the external lateral thrust, and should always be concentric with the pipeline axis, and prevent the normal sliding of the sliding sleeve from being obstructed.
2. During maintenance, check the installation condition of the seal and tighten the bolts in time to ensure that the seal has no leakage.
3. If the outer surface of the sliding sleeve of the compensator is severely corroded and the anti leakage effect is not obvious after the bolt is tightened, the compensator should be replaced.
According to the market demand, the packing type sleeve compensator is also designed and manufactured. Its model and specification are the same as those of the front sleeve compensator. Its main characteristics are:
1. Packed sleeve compensator has high reliability, long service life and little maintenance.
2. The packing sleeve compensator can be repaired under normal operation of the pipeline, and the maintenance process is simple. (Special filling tools and sealing packing are required.)
3. The filling type shall be indicated when ordering.
Some customers always complain that the service life of the compensator is short, and the effect of maintaining the thermal expansion and cold contraction of the pipeline is lost before it is used. What is the corrosion damage of the compensator related to? What causes the damage?
In fact, the corrosion damage of the corrugated compensator is related to both the internal recommended medium and the external environmental conditions. When the internal medium meets the requirements of the specification, the corrosion of the external environment is the main reason for the damage of the compensator. There are two kinds of installation environments for the compensator. One is the overhead pipe network. After the completion of the installation, the pipeline and the corrugated contraction joint are usually wrapped in the sealed outer sheath. When the outer sheath is not sealed satisfactorily, corrosive media in the atmosphere, such as acid rain, salt spray in coastal areas, will form corrosion of the bellows. But so far, there is no report of corrosion damage of overhead pipelines. The other is buried and paved high. It is the most common way for urban central heating projects. When sewage, open water containing saline alkali, snow melting brine and other corrosive media exist in the trench, corrugated pipes made of 300 series stainless steel usually use one to three heating cycles to corrode and fail. Beijing, Tianjin and other places present the above situation. The ideal trench environment is the most suitable for the normal operation of the corrugated compensator.
There are many types of corrugated compensators, and the directly buried corrugated compensator is the most vulnerable to corrosion damage. Because the pipeline is directly buried in the open, it is difficult to complete the ideal density connection between the contraction joint and the pipeline interface, so the directly buried pipe network is most vulnerable to damage due to external corrosive media.