Analysis of the application of online leak sealing technology in petro-chemical industry
 

Abstract:This paper introduces the online leak sealing technology and application principle of the technology.The real application of sealants injection of online leak sealing technology is emphatically introduced.Through the real operation, the sealants injection type and experience of online leak sealing are described.The effect of leak sealing technology in petro-chemical industry is also analyzed.
 

Key words: online leak sealing,clamps design,sealing compounds,sealants injection type in leak sealing technology.
 

1. Overview:

With the rapid development of industrialization and continuous enhancement of industrial continuous production, the long term running of the system becomes the key about benefit.But due to the fluctuation of process system and corrosion of pipeline and equipment, leakage is inevitable.Because of the different physical and chemical properties of different media, the impact on environment is also different.If we use normal method to repair the leakages,first is that it is difficult to implement,second this way takes a long time to stop leak.Especially when some key parts leak, it is possible for the system to shutdown and the economic loss is large.The function of online leak sealing technology can eliminate leakage online, avoid unwanted plant shutdown, stabilize the system for a long period, and be favored by a lot of production enterprises.Now,many petro-chemical manufacturers pay more and more attention to the application of online leak sealing,professional pressure leak sealing team has been set up, especially the sealants injection type of leak sealing is widely used.But how to apply the online leak sealing technology successfully and implement properly,it has become a problem that more and more clients are discussing.

 

2. Introduction of online leak sealing:

2.1.The basic principle of online leak sealing technology:

Online leak sealing is the technology that when there are leaks on pipes,valves,flanges,elbows,T-pipes or any other equipments,leaking mediums have the temperature, pressure, toxic, flammable, great harmful,people build a sealing cavity on leakage position,use the special tools to pump the injecting pressure higher than the leaking pressure to inject sealing compounds into the sealing cavity properly,and make the sealing compounds full fill in the sealing cavity(the sealants has the characteristics of heat resistance, pressure, resistance to corrosion medium),the sealing compounds are becomed cured and solid when leaking temperature heating them,then the clamps and online leak sealing compouns are in forming a new seal structure based on leaking location,to seal the leak and avoid the plants shutdown, make the system runs for a long period of time.

 

2.2 The online leak sealing technology application scope:

Online leak sealing technology is suitable to repair the medium including water vapor (different levels), air, gas, liquid ammonia, methanol, transformation and hydrocarbons, gas,etc.,whatever the leaks are on the valves, flange, bonnet packing,line hole, crack, nipple and so on.

Applicable temperature range is - 185 ℃ ~ 800℃;

Applicable medium pressure range is vacuum ~ 35 mpa

.Fully meet the requirements of pro-chemical plants production.

 

2.3 The technical features of online leak sealing:

Clamp materials mainly are choosen according to leak medium physical and chemical properties

,must consider the strength and corrosion resistant materials

.Under special circumstances, such as explore risk in the medium environment should also be considered when installation process may cause the sparks.

 

2.4 The fixture design and strength calculation of clamps:

Clamps are the key to leak sealing, it is divided into ring type,cas type,parial type.

The sealing gap size of clamp is an important factor to ensure the sealing effect.For the reasonable design of leaking clamp becomes the embodiment of the leak level.The gap is as small as possible, of course, the smaller the gap, the higher success rate.But the higher precision requirement, the higher production costs.How to design clamps reasonable,it is a problem to each client.

Clamps sealing cavity is used to contain the online leak sealing compounds when injecting compounds.The cavity size is directly affects its sealing result,general requirements of sealing cavity is 10 ~ 15 mm.

If the flange leakage, generally it adopts the ring clamp type.

In such clamp design, people can consider to add seal groove on the surface of the clamp,if flange wrong side we can consider adding amount of convex platform to make up for the wrong side.

 

2.5 How to choose the proper leak sealing compounds:

Sealants are divided into heat curing sealant, the thermal curing sealant and filling type of sealant.The main decision and the selection of sealant are depends on the leaking medium and system temperature.Correct selection of sealants can ensure the successful sealing result.

 

3.Analysis of online leak sealing effect:

Adopting the online leak sealing technology, not only from the economic, but also from the environment and production safety,all have made significant gains.

 

3.1 The economy save:

If mother steam pipe or feed gas pipeline are leak, conventional processing methods are only packing, replacement cushion, or welding, but before that plants must shutdown the system firstly,which cause a big raw materials wasted, and environmental pollution,and un-scheduled plants shutdown is a heavy lost of energy.

 

3.2 Online leak sealing cost:

The cost is depends on clamps cost,sealants cost and tools cost,as well as manpower cost,which these are very low cost compare with the plant shutdown cost.

 

3.3 Environmental protection:

To repair the leaks,it can avoid the leaking medium pollution of the environment.

 

3.4 Safety:

When the leaking medium is explosive or toxic,if people can not repair the leaks timely,it will cause fire, poisoning, or explosion,which are big accidents.

Through the above analysis, generated by the online leak sealing efficiency is obvious.Rational utilization of this online leak sealing technology, it can greatly reduce lost and save energy.Namely protect the equipment and environment,reduce emissions, but also save the materials.This is the reason why many petro-chemical enterprises are paying more and more attention on this online leak sealing technology.

 

4.Conclusion:

Online leak sealing technology is not only injecting sealants type,but also adhesive repair type,and valve stuffing box repair type,valve bonnet repair type,SS strip wrapping type,composite wrapping type,etc.How to use the suitable application in the field, it depends on the actual situation, choose proper types of method to stop leak,in order to achieve the best sealing effect.

Not all leaks are suited for online leak sealing operation.Some too dangerous cases can not be applied leak sealing method,such as leaks on ultra-high pressure and self-seal valve.

If the leaking pipe is corrosion terrible,the pipe wall is very weak,this case is not suitable for normal injecting sealants method,we must apply a special clamp structure.Wrong operation can cause terrible accident.
If the Leakage of medium is toxic or explosive,when do not take appropriate security operation,it can lead to poisoning and explosion accidents.

So in the application of online leak sealing technology, we must be in strict accordance with the safety operations,the scene of serious investigation, and understand the medium & equipment property, and then go ahead to do the work.

 

Because the online leak sealing operation is belongs to the scope of special operation and high risk,we suggest: 1,the online leak sealing personnels must be in professional training;2,to avoid risks, jobs shall be handled by a professional online leak sealing service company;3,Engineers must be equipped with complete safety and protective devices before doing online leak sealing operation.