Copper Tube Information

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brass tube bending services

author:MF manufacturerstime:2022-03-15 14:12:24

Operation order:

(brass tube bending services)brass tube bending services

one、Copper pipe protection:

1、After passing the copper pipe input,The end of the pipe must be sealed during storage,The most common way is to use end cap blockage and tape;

2、The disk must be placed vertically.,To prevent self-weight caused by compression deformation;

3、The copper tube must be higher than the ground with a wooden bracket or the like.,Dust、water proof。

two、Copper pipe processing

(brass tube bending services)1、Main tool:

(brass tube bending services)brass tube bending services

brass tube bending services

2、Copper pipe cutting:Use a copper pipe cutter to cut in the direction of the pipe axis,Copper tube should be slowly clamped to clamp the copper tube when operating,The cutter should be rotated clockwise,Entry regulator that gradually rotates the knife,Gradually enter the knife。Cut the copper tube in the case where the copper pipe does not deform。Can't use saw blade or grinding wheel cutting machine。

3、Go to the burr:Copper tube cutting face will generate burrs,It must be removed and blown up the end of the tube and the tube end。First remove the end of the burr,Remove the burr of the pipe inside the piping with a twinkler or a doctor blade,Rethink the end face with a file,Return the burr of the pipe inside the pipe with a mound knife or a doctor blade。When performing the work of cutting,Please face the cut,To make the copper shovel do not enter the inside of the pipe。If you don't completely remove the burr, Phenomenon of leakage occurs in the expansion site,So remove the burrs carefully。

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Set the bulk to the pipe before processing,Select the model in line with the expansion,Correct expansion size,Should be substantially the same as the size of the connecting pipe。The size of the expansion size is as shown in the right. A Size effect。According to the manufacturer of the production tool,A Size will also be different,Please pay attention。

(brass tube bending services)brass tube bending services


According to the on-site installation requirements, the amount of bending size from the piping is taken and the size is taken from the left side.。

(brass tube bending services)(1)Take the size from the right end or left end quantity of the pipe to be curved。

(brass tube bending services)brass tube bending services

(2)Put the pipe in the elutier。

(brass tube bending services)Fixed lever『0』Dians and zero mark on the handle(No zero mark and the front end of the handle)。

(3)Adjusting the piping,On the side of the tube on the handle『R』or『L』Coherence。

(brass tube bending services)(4)Pressing handle,Bending to the desired angle。Bending slowly,To make wrinkles and deformation inside the pipe。Bending angle must not exceed 90°

(brass tube bending services)brass tube bending services


Φ6.4—Φ19.1After the copper pipe is implemented,Insert piping, This can be brazed between the pipe and the tube.,No need to use fittings to connect。

three Remove the burrs on the cut surface with a mound blade or a doctor blade。

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three、Copper pipe piping:Be sure to press the design map、Construction map construction。

Four、Copper tube installation

1、The copper tube arrangement must be horizontally vertical,Putting standard;

(brass tube bending services)2、Multi-copper tube is arranged in parallel,Uniform spacing;

(brass tube bending services)3、The distance between the two digesters must be greater than1Mide;

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4、Differential tubes must be greater than0.5Mide above can turn;

5、Bronze tube bracket hanging spacing。

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Fives、Nitrogen replacement

(brass tube bending services)Welding,The protective welding must be charged with no mounting in the tube.,To avoid oxide film;method:See below(Nitrogen pressure is0.2kgf/cm2about)

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Note:On the left side of the copper pipe, the cover is sealed.,Leave small void,Save nitrogen。

Main tool:

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six、Copper tube welding

1、Operators must be held,Because it is necessary to produce welding and flames,therefore,Please be sure to wear safety,Utensil(Blister、Leather gloves, etc.)。Please prepare fire devices such as fire extinguishers on the spot.。

2、Tools needed during welding:

(brass tube bending services)brass tube bending services

To ensure the safety of brazing,Acetylene regulating valve with devices that prevent backlash should be used。

(brass tube bending services)Brazing pipe outer diameter and a rough standard for selecting a weld aperture(French style):

brass tube bending services

Toolar pore size,It is difficult to preheat、Heating homework。in addition,Too small aperture,Spending the soldering time。 So use the weld tunnel suitable for the outer diameter of the brazing pipe。

(brass tube bending services)3、Welding step:


Preheated 5 Point:

(brass tube bending services)A、Equal heating for two main materials(Internal and outer tube and around)。

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B、Heating to solder input temperature ·640~780℃(The surface of the base material is dark red)

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C、Adjust the spray flame and its length,Work in the state of the restore flame(Carbonized flame long 5cm),The flame length changes according to the size of the main material。

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D、Flame and piping angle(Controlled heat),Flame and pipe angle control 80~85°

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E、Visual confirmation,Distance from the front end of the carbon,Flame contact location,Flame direction

brass tube bending services(brass tube bending services)

4、Filling solder:

Filling the solder 5 Point:

A、Confirm the range of the solder(Flow range expand)。

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B、Confirm the flow of solder(Different according to the range of the base material heating)。

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C、Let the solder begin to melt from the ace(Gently contact the solder to the base material,Melt at a small amount)。

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D、Flame and solder angle ·The flame is slightly erected from the preheating position。

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E、Visual confirmation(Confirm the front end distance of the carbon、Flame contact location、Flame direction、Final confirmation)。

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Downward、The horizontal direction is relatively easy to braze,And the difficulty is difficult to,Easy to cause refrigerant leakage,Please try your work as much as possible。

(brass tube bending services)5、Copper tube cooling:

The copper tube is not completely cool.,Please do not stop accessing nitrogen。Stop nitrogen in a state in which it is insufficient,Piping Internal oxide film。

seven、Copper pipe purge

Purpose:Remove the oxide film at the time of brazing,Remove dust and moisture。


1、Rose a nitrogen bottle pressure from a pressure reducing valve to5.0kgf/cm2;

2、Check the other end of the tube has no nitrogen;

3、Use wooden block to stay in the pipeline;

4、When the pressure rises to the point where the palm cannot support it,let go;

5、Press the wood block against the nozzle again,repeat④step;

6、Wipe the nozzle with gauze,Rinse repeatedly until dirt and moisture are free;

7、 If not connected or vacuumed right away,The tube must be sealed。

(brass tube bending services)brass tube bending services(brass tube bending services)

Eight、Copper tube air tightness test

1、gist:guarantee24Air pressure remains at40kgf/cm2;

2、Purpose:Verify that the piping system is free of leaks;

3、experiment procedure:Simultaneously pressurize the system liquid and gas pipes with nitrogen

(brass tube bending services)brass tube bending services

Notice:Because gas pressure varies with ambient temperature,Every1℃about0.1kgf/cm2pressure changes。The temperature at the time of pressurization and the temperature at the time of observation should also be recorded,for correction。

Test device diagram:

brass tube bending services

Notice:The outdoor unit valve must be closed during pressurization,Prevent nitrogen from flowing into the outdoor unit;

(brass tube bending services)assignment order:

brass tube bending services

The piping system is divided into several parts for air tightness test,easy to spot leaks,speed up the work process;

Leak detection method when pressure drops

A.Routine inspection:

(brass tube bending services)hearing:Hear loud air leaks;

touch:touch,Feel the leak;

soapy water:Air leaks will bubble。

(brass tube bending services)B.special inspection:

(brass tube bending services)put nitrogen in3kgf/cm2;

add refrigerantR134Ato5kgf/cm2,Nitrogen mixed with refrigerant;

Use a halogen detector、Alkanes(LPG)detector、Electronic detectors, etc. to check;

Still can't find,continue to pressurize to40kgf/cm2 check again,pressure cannot exceed40kgf/cm2。

Note:When the pipe is too long,should be checked in sections。

After the air tightness test,Keep the pressure gauge on the liquid pipe side of the outdoor unit,system remains40kgf/cm2pressure,The purpose is to prevent the airtightness from being damaged。

Nine、Copper pipe insulation

1、gist:There should be no gaps in the interface of the insulation material;

2、reason:Air pipe temperature is very low during cooling,will lose cooling capacity and cause condensation、dripping;High air pipe temperature when heating(50~100 ℃),can cause burns;In addition, the ability of the machine will be affected,even burn out the compressor;

3、Insulation material is foamed polyethylene,heat resistant than120℃(Liquid tubing available70 ℃ above);

Note:If the environment is hot and humid, the above thickness should be increased。

4、Gas and liquid pipes must be insulated separately,Tie it together with tape,See below:

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5、indoor、The interface of the external machine and the welding place of the refrigerant pipe should be insulated after the air tightness test.;

6、Pipe connections and wall penetrations must be insulated;

(brass tube bending services)brass tube bending services

7、Insulation of branch assemblies is particularly important,no gaps,And use the special matching insulation cover,shall not be replaced by other。

ten、Vacuum drying of copper tubes

(brass tube bending services)1、gist:Use vacuum at-755mmHgThe following vacuum pumps;

2、Purpose:Remove moisture from the system;

3、Use vacuum at-755mmHgthe following、Exhaust volume40L/minabove vacuum pump;

(brass tube bending services)4、Outdoor unit does not vacuum,Do not open the air side of the outdoor unit、Liquid side stop valve;

5、Confirm that the vacuum pump is working1more than an hour-755mmHgthe following;if3more than an hour still can not reach-755mmHgthe following,Indicates that there is moisture mixed in or air leakage,need to check;

6、If moisture gets in,must be carried out with nitrogen“vacuum break”:i.e. after vacuum drying,add nitrogen to0.5kgf/cm2,then vacuum again。Repeat this until you keep-755mmHgVacuum and no pressure rise。

7、After vacuuming,Close all valves of the meter diverter first,Turn off the vacuum pump again。

(brass tube bending services)8、It often happens that the airtight test does not leak but leaks when vacuuming,At this point, check the air tightness of the valve。

eleven、The copper pipe is additionally filled with refrigerant

1、gist:Record the amount of additionally charged refrigerant on the outdoor unit body and record book;

2、Under normal circumstances, additional refrigerant charging is required;

3、Vacuum drying is required before additional refrigerant filling;

(brass tube bending services)4、It is best to weigh the refrigerant with an electronic scale;

5、filled,interior should be inspected、Whether there is refrigerant leakage in the flared part of the external unit(with a gas leak detector or soapy water)。

This article comes from the Internet,Edited by HVAC South Society。

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