Performance characteristics of pipeline expansion joint series products

Product description and model of large tie rod transverse corrugated compensator: dn100-dn5000 produced by our company, with pressure level of 0
1mpa-2
5mpa
Connection mode: 1
Flange connection 2
Transverse compensation of connecting pipe connection product: according to the user's requirements instructions: Calculation of the force of the large pull rod transverse corrugated compensator on the support: transverse elastic force: FY = KY & middot; Y bending moment: M = FY & middot; Where: KY - transverse stiffness n / mm, Y - transverse actual displacement (deformation) MML - distance from pipe support to the midpoint of compensator, M
1、 Application of large tie rod transverse corrugated compensator: large tie rod corrugated compensator has the advantages of large compensation, rigid turbidity, no medium pressure thrust, Anquan, no leakage and low cost
It has been widely used in heating pipe network in recent years
2、 Structure and working principle of large pull rod transverse corrugated compensator: the large pull rod corrugated compensator (also known as Fushi) is a flexible component composed of two identical bellows, end pipe, end plate and pull rod
The transverse displacement of pipeline Danping surface or multiple planes can be absorbed through the angular deflection of bellows
The four long pull rods can bear the internal pressure thrust and other additional external forces
The spacing of bolts at both ends of the pull rod has been adjusted before leaving the factory
Before installation, the large pull rod is loose
After the compensator is deformed, the large pull rod can protect the bellows
Pull rod III
characteristics and advantages of large pull rod compensator: 1
Large compensation, no internal pressure thrust and small thrust to the support
2
Anquan has no leakage and is correctly cold tight
3
Low cost
Precautions for the installation of large tie rod transverse compensator: 1
The necessary steps for the installation of compensator shall be planned in advance, and the installation personnel shall be familiar with these steps and the operation instructions and relevant technical data provided by the manufacturer
2
Before installation, check whether the model of the product is consistent with the pipeline design data
3
The large tie rod transverse compensator is a constrained compensator
The installation of this compensator will not make the pressure thrust act on the pipeline support, so the support connected to it is a secondary fixed support
4
On site Hanjie compensator must be well protected with corrugated pipe, which is usually protected with wet neutral asbestos cloth
5
If the length of bellows has been adjusted to the specified requirements when leaving the factory, but the length of bellows is inconsistent with the following table during transportation, the transportation pull rod shall be adjusted to the factory length
6
It is not allowed to adjust the installation deviation of the pipeline by the deformation (compression, tension and torsion) of the corrugated compensator, so as not to affect the normal function of the compensator, reduce the service life and increase the load of the piping, equipment and supports
It is recommended that a companion flange on the pipe system be kept until the compensator is in place
7
After the compensator is installed in the pipeline and before pressure test, on the premise of ensuring correct fixation and guidance, remove the transportation and fixing components (such parts are generally pasted with post installation removal mark or painted with yellow paint), or adjust the limit device to the specified position according to the design requirements
8
All moving elements of the compensator shall not be jammed by external components or within its moving range
There shall be no foreign matter preventing its deformation between the corrugations of the bellows, and the dirt of the bellows shall not be cleaned with cleaning agent containing Lu or steel wire brush
9
When used for steam pipeline, the horizontal pipeline shall have low point drainage, the vertical pipeline shall have drainage device on the horizontal pipeline, and cecum is not allowed to avoid water hammer
The oil pipeline shall be equipped with oil return device and Anquan valve to prevent sharp pressure rise during oil rise
Flammable and explosive pipelines shall be equipped with safety valves, and Youxiao protective devices shall be set around the compensator in flammable and explosive pipelines to avoid casualties caused by baozha
10
It is forbidden to connect the ground wire to the bellows during Hanjie
During the installation of the large tie rod transverse corrugated compensator, attention must be paid to the influence of the installation environment, circulating medium and temperature
Only considering the wide coverage can the probability of accidents be reduced in the future use
Product features of metal corrugated expansion joint: metal corrugated expansion joint is a device that absorbs the size change of pipeline, conduit or container and equipment caused by thermal expansion and cold contraction
Its metal corrugated pipe is the main compensation product
Its material is stainless steel, carbon steel, stainless steel lined with polytetrafluoroethylene, etc
It is widely used in petrochemical, electric power, heating, cement and other industries
It is relatively resistant to high temperature and pressure
Function and working principle of metal compensator: bellows compensator, also known as expansion joint and expansion joint, is composed of bellows, end pipe, support, flange and conduit of the main body
Metal expansion joint is a kind of compensation product that uses the expansion deformation of the elastic element of bellows compensator to absorb the size change of pipeline and conduit caused by thermal expansion and cold contraction
It can be absorbed axially, horizontally and angularly
It is used for heating displacement, mechanical vibration and noise reduction of pipeline equipment and system
The following two points shall be noted during production: 1 Clean the plate before welding
Hydrogen arc welding requires high surface quality of materials, which must be strictly cleaned before welding
Oil stain, moisture, dust and oxide film on both sides of the surface near the weld junction of the workpiece within at least 20mm
Otherwise, it will affect the arc stability, deteriorate the weld formation, and may lead to pores, inclusions, non fusion, etc
2
You can use Youji solvent to remove oil and dust, such as gasoline, ethylene, carbon tetrachloride, etc
, or prepare special chemical solution for cleaning
Mechanical cleaning or chemical cleaning can be used to remove the oxide film
It should be noted that the storage time from cleaning to before is generally no more than 24 hours, and the process parameters should be reasonably controlled
For 0 & middot; The current of stainless steel plates below 5mm is small, generally not more than 30a, and the welding speed is generally more than 22m / h (see Table 2 for specific parameters)
At the same time, the influence of welding speed on gas protection effect should be considered: excessive welding speed and serious deviation of shielding gas will expose tungsten, arc column and molten pool to the air
Therefore, corresponding measures must be taken, such as increasing the flow of shielding gas or tilting the welding torch forward at a certain angle, so as to maintain good protection
Installation requirements of metal corrugated expansion joint: regardless of the structure and installation form, the bellows expansion joint is used to compensate the relative displacement of the pipeline between the fixed supports at both ends, that is, only one corrugated expansion joint is allowed to be installed between the two fixed supports, otherwise the compensation amount of the expansion joint will become an uncertain value
The fixed support shall be able to meet the combined force of axial inward pressure thrust, elastic force, friction force, weight of pipeline and medium in pipeline and other forces caused by wind load on the fixed support under working conditions
The strike length at the bend of directly buried pipeline is less than 30d or the pipe diameter & gt; A fixed support shall be set at 325
For the fully balanced corrugated expansion joint, the main fixed supports on both sides only need to bear the force of elasticity, friction and other forces on the fixed support, but cannot be mixed with the non fully balanced corrugated expansion joint
If they must be mixed, the two main fixed supports shall be designed to bear the internal pressure thrust, that is, the blind plate force shall be considered, For corrugated expansion joints with axial displacement (except pressure balance type), intermediate fixed support and main fixed support shall be set at the place where the flow direction of elbow changes, the diameter change of straight pipe section, the place where the branch pipe equipped with compensator enters the main pipe, and the connection of intermediate valves of two compensators
When the forces at both ends of the pipe system are completely symmetrical or the pressure thrust is completely borne by the expansion joint, Considering the occurrence of accidents, the bearing capacity shall consider the sum of not less than 0
75 ~ 0
8 times of elastic force and pressure thrust
The pipeline pressure and thrust of large tie rod transverse and angular expansion joints are borne by tie rod and hinge
If the pipeline is subject to the overall hydrostatic test, the secondary fixed pipe support at the end of the pipeline equipped with corrugated expansion joints shall be reinforced
Make sure that the pipeline does not move or rotate reversely, bixu check whether the fixed supports at both ends of the compensation pipe section of the corrugated expansion joint are firm with the pipeline and bearing components according to the design requirements, and check whether the main fixed support is designed according to the bearing capacity of 1
5 times the internal pressure thrust
If the support and pipe section are not fixed or the bearing capacity of the support is insufficient, the hydrostatic test shall not be carried out, otherwise the corrugated expansion joint will be damaged due to the internal pressure thrust, and the auxiliary components on the corrugated expansion joint cannot be regarded as bearing the internal pressure thrust instead of the fixed device
Because there is a small amount of unbalanced force in the pressure balanced bellows expansion joint, the requirements for the fixed support can be designed according to the factors such as pressure thrust, friction and the Fantan force of the bellows
For the corrugated expansion joint installed in the pipe system, according to the displacement requirements, the linear guide sliding support and plane guide sliding support shall be designed at the moving end of the corrugated expansion joint to ensure that the corrugated expansion joint will not twist and other deformation during operation
After the hydrostatic test, the ponding in the wave shell shall be drained as soon as possible, and the outer surface of the wave shell shall be dried quickly