空调铜管施工方案

Construction Plan for Air Conditioner Copper Pipe

空调铜管施工方案

一、Generals 工程概况

This project comprises roof air conditioning unit, indoor built-up type air conditioning box, and connection of copper pipeline in two equipment rooms. The site construction of copper pipe is the main quality point of construction.

本工程包括屋顶空调机组，室内组合式空调箱及两设备间的铜管管线的连接。其中现场铜管施工为本程的施工质量重点。

二、Copper pipe selection 铜管的选择

Category Standard outer

diameter

（allowable

deviation）DO

mm Wall thickness

（allowable

deviation）

t mm

Max. operating

pressure 最高

使用压力

PMPa

Allowable tensile

stress 充许拉

伸应力

o aN/mm2

O and OL 19.05(±0.03) 1.00(±0.09) 3.616 33(Temperature

at 125℃的)

allowable tensile

stress）22.22(±0.03) 1.15(±0.09) 3.563

28.58(±0.04) 1.45(±0.10) 3.49

类别标准外径（允许

差）DO mm 壁厚（允许差）

t mm

最高使用压力

PMPa

充许拉伸应力

o aN/mm2

O及OL 19.05(±0.03) 1.00(±0.09) 3.616 33(温度在125℃

的)充许拉伸应

力）

22.22(±0.03) 1.15(±0.09) 3.563

28.58(±0.04) 1.45(±0.10) 3.49

Category Standard outer

diameter

(allowable

deviation）DO

mm Wall thickness

（allowable

deviation）

t mm

Max. operating

pressure

PMPa

Allowable tensile

stress

o aN/mm2

1/2H or H 19.05(±0.03) 1.00(±0.09) 6.684 61(Temperature

at 125℃)

allowable tensile

stress）22.22(±0.03) 1.00(±0.09) 5.694

28.58(±0.04) 1.00(±0.09) 4.391

类别标准外径（允许

差）DO mm 壁厚（允许差）

t mm

最高使用压力

PMPa

充许拉伸应力

o aN/mm2

1/2H或者H 19.05(±0.03) 1.00(±0.09) 6.684 61(温度在125℃

的)充许拉伸应

力）

22.22(±0.03) 1.00(±0.09) 5.694

28.58(±0.04) 1.00(±0.09) 4.391

Category of tubing is distinguished by maximum operating pressure (design pressure), according to drawing designed and construction specification, refrigerating fluid shall use R407C

or equivalent other refrigerant. R407C design pressure is generally about 3.45MPa, R410A design pressure is generally about 4.15MPa.

配管的类别根据最高使用压力(设计压力)来区分的，根据图纸设计及施工说明，制冷剂采用R407C或相近的其它环保冷媒。使用R407C设计压力一般为3.45MPa左右，R410A的设计压力一般为4.15MPa左右。

5 Computation formula of wall thickness 壁厚的计算公式

The computation formula of the compulsory copper pipe (TP2M) thickness is as follows.

铜管(TP2M)必须厚度的计算公式、如下。

ｔ= [(Ｐ×OD)／(2σa + 0.8P)] +α(㎜)

ｔ：compulsory wall thickness 必须的壁厚(㎜)

P：max. operating pressure (design pressure) 最高使用的压力(设计压力) (MPa)

OD：standard outer diameter 标准外径(㎜)

σa：min. allowable stress at temperature 125℃在125℃的基本许可应力(N／㎜2)

＊σa = 33 (N／㎜2)

α：Corrosion thickness (mm) ＊but, for copper pipe, it shall be 0(mm).

腐蚀厚度(㎜) ＊但是，对铜管的话为0(㎜)。

Example of design selection （TP2M）:the following takes O-type (TP2M) copper pipe design as example

设计选择示例（TP2M）:以下以O型（TP2M）铜管设计为例

① Wall thickness selection of R407C refrigerating system exhaust pipe set, it is assumed

that the outer diameter of exhaust pipe set is φ19.05, the wall thickness selection method

shall be as follows:

R407C制冷系统排气管组壁厚选择，假设排气管组外径φ19.05，其壁厚选择方法如下：Maximum pressure of R407C refrigerating system at exhaust air side takes 3.45MPa, calculation is as follows:

R407C制冷系统排气侧最高压力取3.45MPa，计算如下：

Wall thickness 壁厚ｔ= [(P×OD)／(2σa + 0.8P)] +α(㎜)

=（3.45×19.05）/（2×33+0.8×3.45）+0

=0.9558mm

Taking round number 取整，t=1.0mm。

Note: φ19.05 copper pipe wall thickness deviation class V specified in GB/T1804 may be ±0.08mm, in this way, if supplier uses copper pipe with wall thickness deviation of -0.08mm to produce pipe set in order to economize cost, its wall thickness shall select 0.29mm. we can get to know from the calculation result, when design pressure of the pipe set is 3.45MPa, pipe cracking may happen. At this time, we must add copper pipe wall thickness to ensure the pipe set not cracked, or to explicitly stipulate in the technical requirement the pipe set wall thickness within suitable deviation, i.e. deviation range at （-0.4，+0.08）mm, to avoid the pipe set from cracking.

注：国标GB/T1804规定φ19.05的铜管壁厚V级偏差可以是±0.08mm，这样如果供货厂家为节省成本，采用壁厚偏差-0.08mm来生产管组，则其壁厚就会选取为0.92mm了，这样由计算结果可知，该管组在设计压力为3.45MPa时，就会有裂管的隐患了。这时必须通过适当增加铜管壁厚来保证该管组不会爆裂，或者在技术要求中明确规定管组壁厚在适当的偏差内，即偏差范围在（-0.4，+0.08）mm内，以免除管组爆裂隐患。

②R410A

Wall thickness selection of refrigerating system exhaust pipe set, it is assumed that the outer

diameter of exhaust pipe is φ19.05, the wall thickness selection method is as follows: 制冷系统排气管组壁厚选择，假设排气管组外径φ19.05，其壁厚选择方法如下：

R410A refrigerating system max. pressure at high pressure side is designed as 4.15MPa, its wall thickness calculation is as follows:

R410A制冷系统高压侧最高压力设计为4.15MPa，则其壁厚计算为：

Wall thickness 壁厚ｔ= [(Ｐ×OD)／(2σa + 0.8P)] +α(㎜)

=（4.15×19.05）/（2×33+0.8×4.15）+0

=1.14mm

Take round number t=1.2mm, such wall thickness can also meet design requirement according to GB/T1804. If the pipe set does not need folding, select O-type pipe with wall thickness of 1.2mm, the cost is increased by 20% to be compare with H/2 pipe with wall thickness of 1.0mm. Such design is uneconomical. Whereas, according to table 2, we may get to know that when we use H/2 (TP2Y) copper pipe, the wall thickness is 1.0mm, its resistance to pressure can reach 6.684MPa, fully conforming to the design pressure required. Therefore, under such a circumstance, we should select H/2 (TP2Y) copper pipe with wall thickness of 1.0mm.

进行取整t=1.2mm,此壁厚按照国标GB/T1804规定V级偏差也能满足设计要求。如果该管组不需要折弯，选择壁厚为1.2mm的O形管，相比选择壁厚为1.0mm的H/2型管，成本增加了20%，这样设计是不合算的。而根据附表2可以知道采用H/2（TP2Y）铜管，壁厚为1.0mm时，其耐压可达到6.684MPa，完成符合设计压力的要求，因此这种情况下应该选择壁厚为1.0mm 的H/2（TP2Y）铜管。

It also can be calculated as per formula, when H/2 (TP2Y) copper pipe bears 4.15Mpa pressure, the wall thickness required is t=0.584mm. Therefore, selecting H/2 (TP2Y) copper pipe with wall thickness of 1.0mm can fully meet the 4.15Mpa design pressure required, just it is a pity that the H/2 (TP2Y) copper pipe cannot be folded, however, we can use matched bend to solve it.

也可以根据公式计算，H/2（TP2Y）铜管承受4.15Mpa的压力时，需要的壁厚是

t=0.584mm。所以选择壁厚为1.0mm的H/2（TP2Y）铜管是完全符合4.15Mpa的设计压力要求的，只可惜H/2（TP2Y）型铜管都不能折弯，但可以使用与其相配套的弯头来解决。

As per the above calculation and analysis, TP2Y type shall be selected as copper pipe material for this project.

根据以上计算及分析，本工程铜管材料选择为TP2Y型。

三、Copper pipe welding 铜管的焊接

1、Get ready for tubing 准备与配管

1.1 examine the oxygen cylinder and acetylene cylinder for enough quantity

检查氧气瓶和乙炔瓶内的量是否足够。

1.2 check drawing requirement, ensure all parts are complete and undamaged, with good function.

核对图纸要求，保证各部件的齐全无缺，功能完好。

1.3 ensure pipeline flat and upright, note all valve fittings directivity.

保证管路光路横平竖直，注意各阀件的方向性。

1.4 use tape measure to measure relative length as per sizes and pipe diameters required in drawing and record the location with marker pen.

根据图纸要求的尺寸和管径，用卷尺量取相应的长度，并用线号笔几下位置。

1.5 for larger copper pipe, after it is fixed, use cutting knife to remove it, ensure cutting opening flush and non-deformation.

较粗的铜管要固定后，再用割刀拆下，要保证割口平齐，不变形。

1.6 rasp the cutting opening sharp edges with file, and wipe it with cleaning cloth.

用锉把割口毛边锉平，并用抹布擦拭干净。

1.7 clean the welded pipe fitting surface or flaring, horn mouth should be smooth, circular, burr-free and no cracking, even thickness, polish clean the copper pipe connector to be welded with abrasive paper, and wipe it clean with dry cloth finally. Otherwise, it will influence welding flux flow and welding quality.

将要焊接管件表面清洁或扩口，扩完的喇叭口应光滑、圆正、无毛刺和裂纹，厚度均匀，用砂纸将要焊接的铜管接头部分打磨干净，最后用干布擦干净。否则，将影响焊料流动及焊接质量。

1.8 in addition to welding between red coppers, all pipe fittings should be cleaned with gauze or stainless steel wire before welding, revealing glossy metal surface.(inner surface should also be cleaned, metal filing and sand grains should be removed and cleaned)

除紫铜与紫铜焊接外，所有管件在焊接前都应用纱布或不锈钢丝刷清理，露出光亮金属表面。（内为表面均要清理，金属屑及砂粒应清除干净）

1.9 overlap the copper pipe to be welded and insert into (note the sizes) and align center of circle.

将要焊接的铜管互相重叠插入（注意尺寸）并圆心对准。

1.10 copper connector and insertion depth of copper pipe and clearance see the table. (insertion depth approximately equivalent to pipe diameter)

铜管接头与铜管插入深度及间隙见表。（插入深度约等于管径）

Min. clearance Max. clearance Insertion depth Copper wire size DO

mm

19.05 0.002 0.006 5/8"

22.22 0.002 0.006 3/4"

28.58 0.002 0.007 29/32"

铜管规格DO mm 最小间隙最大间隙插入深度

19.05 0.002 0.006 5/8"

22.22 0.002 0.006 3/4"

28.58 0.002 0.007 29/32"

2 Protection 保护

2.1 Pipe to be welded connect to low velocity nitrogen when welding to avoid oxidation.

焊接时应在被焊管通低速氮气，防止氧化。

2.2 Acetylene gas should get through non-oxidation welding generator to prevent the outside surface of weldment from oxidation.

乙炔气应通过无氧化焊接发生器，防止焊接物件外表面氧化。

2.3 Welding 焊接

2.3.1 during welding, preheating should be done to the weldment, heat the copper pipe welding point with flame. When copper pipe is heated to purple red, move away the flame and remain the welding flux on the welded junction, make the welding flux melt, flow into copper pipe welded. Heated temperature can reflect temperature by means of colors, dark read: about 600℃; crimson: about 700℃; orange red: about 1000℃.

焊接时，必须对被焊件进行预热。将火焰烤热铜管焊接处，当铜管受热至紫红色时，移开火焰后将焊料靠在焊口处，使焊料熔化后流入焊接的铜件中，受热后的温度可通过颜色来反映温度的高低，暗红色：600摄氏度左右；深红色：700摄氏度左右；橘红色：1000摄氏度左右。

2.3.2 during welding, gas welding flame shall not directly heat welding rod (phos-copper solders), adding welding rod location shall be in opposite of the heating direction.

焊接时，气焊火焰不得直接加热焊条(磷铜焊料)，加焊条位置应与加热方向相反。

2.3.3 the components easily deforming and damaging at high temperature condition shall have relative protective measures. Equipment close to the welding points should be wrapped with wet gauze and the perform welding.

对于高温条件下易变形，损坏的部件应采取相应保护措施。靠近焊接点的设备要用湿纱布包扎接口后再进行焊接。

2.3.4 during welding, when anneal copper pipe after welding, annealing temperature is not less than 300℃.

焊接时，在焊完后将铜管进行退火时，退火温度不低于300摄氏度。

2.3.5 After welding, cool down, clean internal oxide and welding slag with dry nitrogen gas.

焊接完毕后，冷却，用干燥氮气清理管内氧化物和焊渣。

2.4 Repair welding 补焊

2.4.1 repair welding the leak point of weld found during pressure test. Repair welding should let out the nitrogen gas for system pressure test, and after welding conduct pressure test again.

在试压过程中发现焊接有渗漏的地方应进行补焊，补焊时要将系统试压的氮气放掉，焊后要重新试压。

2.4.2 before repair welding, wipe cleaning the oxide layer of surface with gauze. After welding, remove the scale cinder.

补焊前要将表面的氧化层，用纱布擦净。补焊后，要将氧化皮清除干净。

2.4.3 After all welding work completes, blow down the system with nitrogen gas.

全部焊完后，要用氮气将系统吹净。

2.5 Pressure test 试压

2.5.1 After completion of copper pipe welding, close the pipeline for airtight test. Connect the test pipeline to the nitrogen gas cylinder with high pressure hose, and install a pressure gauge with a range of 5 MPa.

在铜管焊接完毕后，封闭需要作气密性试验的管路。将该试验管路用高压软管与氮气瓶相连、并装一只量程为5 MPa的压力表。

2.5.2 force pressure to 0.3MPa, remain pressure for 3 minutes, examine it for pressure drop. If pressure drop exists, the system has large leak point, it can be easily found.

加压到0.3MPa，保持压力3min，检查有否压力下降。若压力有下降，系统有大的漏点，很容易找到。

2.5.3 if force pressure to 0.3MPa, remain pressure for 3 minutes and no pressure drop is found, slowly force pressure to 1.4MPa, remain pressure for 10 minutes, examine it for pressure drop. If pressure drop exists, check leak point and repair welding.

若加压到0.3MPa，保持压力3min后无压力下降，则缓慢加压到1.4MPa，保持压力10min，检查有否压力下降。若压力有下降，则查漏补焊。

2.5.4 if force pressure to 1.4MPa, remain pressure for 10 minutes and no pressure drop is

found, continue step by step (each step force pressure 0.28-0.3MP, each step remain pressure for 10 minutes), force pressure to 2.8MPa (applied for R407C refrigerating fluid), remain pressure for 24 hours, examine for pressure drop. If there is pressure drop at this time, it means the system exist less leak point.

若加压到1.4MPa，保持压力10min后仍无压力下降，则继续逐级（每级加压0.28-0.3MP，每一级保压10min）加压到2.8MPa（适用于R407C制冷剂），保持压力24h，检查有否压力下降。此时若有，表示系统存在微小的漏点。

2.5.5 if R410A refrigerant is applied, boost the max. test pressure to

3.8MPa, measuring the range of pressure gauge shall be boosted. The rest procedure shall be the same.

如是R410A制冷剂适用则应将最高试验压力提高到3.8MPa，测量压力表的量程也要随之增大，其余程序相同。