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brazing brass tubes

author:MF manufacturerstime:2022-03-13 10:11:48

brazing brass tubes

(brazing brass tubes)1、welding

1)Brazing operation

Brazing material:

Soft soldering and brazing2kind,Brazing must be used。


Copper+Copper:BrazingBcu93P(GB 6418),Noweight。

(brazing brass tubes)Gas flux:Can prevent the surface of the copper tube and a brazing,Recommended Use。

Brazing temperature:820-860℃(Brass tube is light red)。

2)Security confirmation before homework

a.Confirmation of the construction personnel。

b.Workwear confirmation(helmet、clothing、Safe bag、Safety shoes, etc.)。

c.Description of the workplace and operating environment。

(brazing brass tubes)d.Work division。Work content、Method and order。Countries。

e.production“Construction plan”。

f.Formulate the person in charge of each group。

g.Explain that there may be like electric shock、Fire and other accidents。

h.Guide correctly uses electric machinery。


j.Apply for application when using an open fire,And get the approval of the on-site safety person。

k.According to local regulations,Accept fire department guidance。

l.Clear tool。Please click on the tool after the receipt will also,If necessary, refrigerant piping system is supplemented,Unused。


a.Construction personnel must be eligible。

Be sure to follow local regulations,Flame operation by qualified personnel。

(brazing brass tubes)b.Wear a joint work suit(It is best to)、safety shoes、helmet、leather gloves、protective glasses、Dust mask, etc.。

Be sure to use the welding gun with back to prevent the valve,Be sure to ensure safety。

c.Be careful not to be burned by flames and heating parts。

d.Carefully operate gas storage bottle,Introduction。

e.Reward the flammable object around。If you can't move away,Do a good job in fire treatment(If you can use a fire cover, etc.)。

f.More ventilation to prevent harmful gases。

g.Measures must be taken in all places with security issues。

h.Differential pipe joint、Operation around the tube,Should be as best as possible,It is difficult to master heating at high work,Moreover, it is easy to melt the welding portion of the diverged tube itself and cause leakage.。


brazing brass tubes

brazing brass tubes

brazing brass tubes

brazing brass tubes

brazing brass tubes

brazing brass tubes

brazing brass tubes

brazing brass tubes

brazing brass tubes

i.To avoid difficult brazing,You can prefabricate one component below.。

4)assignment order

Welding operation basic process:

(brazing brass tubes)a.Brazing

Polish——Metal material grinding the connection。(Removation of oxide film,Non-woven fabric,Grinding cloth,sandpaper)

Degreasing——If there is oil,Sensating treatment with acetone or alcohol solvent。

At the same time0.8MPa(Gauge)Compressed air blows。The number of purge should not be less than3Second-rate,Until dilated。

b.Verify that the gap between the tube and the joint is suitable

(brazing brass tubes)Insert the connector into the pipe,Then put it down,If you can rely on friction without falling, it is considered appropriate.。

c.Nitrogen protection

Copper tube is fierce surface oxidation at the brazing temperature,In order to effectively reduce the production of intraoperative oxidation of copper tubes,Require nitrogen protection against copper tube。After the copper pipe assembly,Internal nitrogen in the copper joint。


Air pressure0.5±0.1kgf/cm2(Relative pressure),Ensure that the nitrogen flow charged in the workpiece is4~6L/min(Hand touchs the feeling of airflow)。

After the assembly begins to nitrogen nitrogen, cooling and continuing nitrogen10Second or more。

Key points for nitrogen(See below):

◆ Fast connector and inflatable gun should be closed when nitrogen,Make all nitrogen into the tube。

◆ Nitrogen is nitrogen to ensure that nitrogen reaches each welded joint,Effectively discharvation。

(brazing brass tubes)◆ At the time of continuous nitrogen, there must be a ventilation.,Otherwise, the gas is essential from the gap when welding.,Difficulties in welding packing,And easy to produce pores。

d.Welding heating

◆ Brazing is flame brazed,Must obey the relevant security operation regulations。

◆ Confirm that there is a nitrogen in the copper tube before heating.。

◆ Brazing purple copper,Use a neutral flame or a slightly reduced flame,Generally adopt a flame。The heat should be uniform at the copper joint,And pay attention to allocate heat according to the material size of the tube。Generally preheating insertion tube,Tube fit;Swing back and forth in the direction of the joint,Make it evenly heated to approaching brazing temperature,Surround copper tube to the brazing temperature(Copper tube is light red),At the same time, the solder is also surrounded by,Uniformly fill the joint gap,Slowly remove the torch,And continue to add a small amount of solder,Welding angle。

◆ When heating, you cannot directly use the flame after welding rod.,Heating time is not too long。

◆ Pay attention to the direction of the flame when welding,Avoid glue sleeve、sponge、Wire, etc.。

e.Welding treatment(cool down)

(brazing brass tubes)◆ After welding, there is a condition for nitrogen protection in the tube.,Can be heated to copper tube discoloration at the joint(200-300℃),Annealing processing。

◆ Before the weld is completely solidified,Can not move the solder or vibrate。

◆ Water-cooled welding,Should prevent water from entering the interior of the copper pipe,Still avoiding the surface residual water flow in the tube when placing the weld。

f.Brazing quality and inspection

Weld surface smooth,Uniform filling is even full,Naturally arc transition。Brazing joints have no burning、Welding block、crack、Weld surface rough surface、Burning and other defects。Welding no air hole、Slag、Unfair、Duvement、Water tumors and other defects。

(brazing brass tubes)5)other

a.When brazed below,Can be a simple stand。(Such as2Ladder)

b.Brazing operation,Easy to do or horizontally。Upward job,Then brazing is easy to fall,Requires high technology。

c.cool down

In order to prevent the burns of the subsequent operation,Wet cloth can generally be used(Low moisture,Mainly reflected in the cooling welding site, no drip is subject to,Due to different shrinkage rates of copper and weld materials,To prevent the brazing from cracking)Waiting for cooling welding。

d.After the completion, check the following

(brazing brass tubes)Welded seam no air hole and shrinkage hole。

Is there any obvious?“Brazing”Phenomenon。

2、Painting of pipeline

After the welding is completed,Pipeline must be blown。

Painting is the foreign matter in the tube with nitrogen pressure(dust,Moisture,Oxidized skin caused by welding)。

1)Main purpose:

a.Oxide caused by insufficient fillet welding in the tube。

b.Remove impurities and moistures in the tube due to improper storage and transportation。

c.Check if the connection between the pipeline system between indoor units and outdoor machines has large leaks。

(brazing brass tubes)2)Painting step:

a.Pack the pressure on a nitrogen bottle。

b.Pressure gauge high pressure end(Tube)Fluorine。

c.Blind plugAAll copper pipe interfaces outside the side are blocked。

d.Open a nitrogen bottle valve,Maintain pressure28kgf/cm2。

e.Check if nitrogen flows through the indoor unitATube。


With the insulation material in your hand,When the pressure is very unable to stay,Quickly release the insulator。Use insulator to the mouth,Such a few times,Then use the wooden plate with blank paper from the sewage300~500mmCheck,There is no obvious booty on white paper,Clean is clean。

g.Close nitrogen main valve。

h.Indoor unitBRepeat the above operation。

i.After the liquid pipe is blown,Painting the trachea,The purge step is the same as the purge the pipeline step.。

(brazing brass tubes)brazing brass tubes

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