铜管道系统出现故障是罕见的。如果出现故障，则导致故障的可能原因是多种多样的。最常见的故障原因是：
Failure in a copper plumbing system is rare,
but may occur due to a variety of reasons. The most common causes
of failure are: |
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| 1. |
流速过快会导致管道或管件内部侵蚀-腐蚀或受到冲击（撞击或敲击）损伤。正是由于这个原因，铜管行业对于铜管道系统在下列不同环境下做出流速限制：
Excessive fluid velocity causes erosion-corrosion
or impingement (to strike or hit against) attack in the tube and/or
fitting. For this reason, the copper plumbing industry has establish
design velocity limits for copper plumbing systems to the following:
热水 > 60oC
Hot Water > 140oF (60oC)
| 0.6至0.9米/秒
2 to 3 feet per second
(0.6 to 0.9 meters per second) |
热水 < 60oC
Hot Water < 140oF (60oC)
| 1.2至1.5米/秒
4 to 5 feet per second
(1.2 to 1.5 meters per second) |
冷水
Cold Water
| 1.5至2.4米/秒
5 to 8 feet per second
(1.5 to 2.4 meters per second) |
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| 2. |
局部高流速和/或湍流。在焊料焊接之前，没有修整或清理毛刺的管道端口以及管道坑的存在，或者流体的突然转向，都可能产生导致局部高流速的原因。
Localized high velocities and/or turbulence.
The presence of a dent, tube ends which are not reamed or deburred
before soldering, and sudden changes in direction can all cause localized
high velocity conditions. |
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| 3. |
典型例子是由于针孔泄漏导致的焊剂侵蚀，通常发生在水平管道的底部。焊剂是一种带有轻微腐蚀性的液体或石油基的粘合剂，包含欣的氯化物和氨。除非焊剂从系统内冲洗掉，否则焊剂将残留在管道底部并且保持活性状态。美国材料实验协会ASTM
B 813“铜和铜合金管道焊料应用中的液体和粘合焊剂”标准中，限制焊料焊剂的腐蚀性，确保这些焊剂能够被冷水冲刷掉，并且在以后的安装过程中焊剂残留容易被清除掉。
Flux Corrosion is typified by pin hole leaks,
generally in the bottom of a horizontal line. Fluxes are mildly corrosive
liquid or petroleum-based pastes containing chlorides of zinc and
ammonia. Unless the flux is flushed from the system, it will lay in
the bottom of the tube and remain active. ASTM B 813, "Liquid
and Paste Fluxes for Soldering Applications of Copper and Copper-Alloy
Tube," limits the corrosivity of soldering fluxes and ensures
that these fluxes are flushable in cold water, which facilitates easy
removal of flux residue following installation. |
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| 4. |
电化腐蚀可以定义为在环境与材料之间电化学相互作用对材料结构所产生的破坏。通常这种过程是缓慢的，但且长期持续，并且以异金属的存在为条件。电化腐蚀要求在某个异金属表面区域存在电流流动。为了实现电路循环，必须存在两个电极，一个阳极和一个阴极，它们必须通过电解液（水）连接，通过电解液电流才能够流过。在阳极溶解的金属数量与电子流量成正比，它们与两种金属的电压和电阻密切相关。管道系统采用的异金属可能会也可能不会产生问题。例如，铜和钢可能是管道系统中最常见的异金属。在封闭系统内，例如制冷或热水管道，采用异金属可能不会产生严重问题；这是因为在水中实际上没有氧，因此腐蚀作用被抑制。在必须采用异金属的地方，有些规程要求这些异金属之间应该由绝缘活接头或类似的管件隔离开来。其效力取决于电动势系列（EMF）表上异金属之间的距离，阴极与阳极面积比，分解度，搅拌强度，温度，溶解盐的存在，以及其他因素。
Galvanic Corrosion may be defined as the destruction
of a material by electrochemical interaction between the environment
and the material. Generally, it is slow but persistent in character
and requires the presence of dissimilar metals. Galvanic corrosion
requires the flow of an electric current between certain areas of
dissimilar metal surfaces. To complete the electric circuit, there
must be two electrodes, an anode and a cathode, and they must be connected
by an electrolyte media (water) through which the current can pass.
The amount of metal which dissolves at the anode is proportional to
the number of electrons flowing, which in turn is dependent upon the
potential and resistance of the two metals. The use of dissimilar
metals in a plumbing system may or may not create a problem. For instance,
copper and steel are perhaps the most common dissimilar metals found
together in a plumbing system. In closed systems, such as a chilled
or heating water piping, the use of dissimilar metals may not create
a serious problem; this is because there is virtually no oxygen in
the water and corrosion relations tend to be stifled. Where dissimilar
metals must be used, some codes require that they should be separated
by dielectric union or a similar type of fitting. The effectiveness
depends upon; distance between the metals on the electromotive-force
series (EMF) chart, ratio of cathode to anode area, degree of aeration,
amount of agitation, temperature, presence of dissolved salts, and
other factors. |
本样本所采用的标准单位是美国常用单位；所提供的公制单位仅供参考。每个系统所列的参数值并不是准确的。
U.S. customary units in this document are
the standard; the metric units are provided for reference only. The
values stated in each system are not exact equivalents. |
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简略的EMF系列
ABBREVIATED EMF SERIES
（电动势系列；在海水中常用的管道材料）
(Electromotive-Force Series; Common Piping
Materials in Sea Water) |
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阳极（+）被动
CATHODE (+) Passive |
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金 -
GOLD - |
固定装置，水龙头，电镀
Fixtures, Faucets, Plating |
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白金，铂
PLATINUM |
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银 -
SILVER - |
铜焊合金，含银焊料
Brazing alloys, Silver-bearing solders |
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蒙乃尔（67%镍 - 33%铜） -
MONEL (67% Ni - 33% Cu) - |
特殊管道和设备
Specialty piping & equipment |
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铜镍合金 -
CUPRO-NICKEL - |
冷凝器，船舶，核能
Condensers, Marine, Nuclear |
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铜 -
COPPER - |
压力，排水、排渣与放气，气体，空气，制冷，等等
Pressure, DWV, Gases, Air, Refrigeration, etc. |
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红铜（85/15 - 红）-
BRASS (85/15 - Red) - |
铸造管件，阀门
Cast fittings, Valves |
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黄铜（70/30 - 黄）-
BRASS (70/30 - Yellow) - |
煤气旋塞，管件，连接件
Gas-cocks, Fittings, Connectors |
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铅 -
LEAD - |
焊料，管道，板材，涂层，衬料
Solder, Pipe, Sheet, Coating, Lining |
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锡 -
TIN - |
焊料，涂层，衬料
Solders, Coating, Lining |
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铸铁 -
CAST IRON - |
压力，排水、排渣与放气
Pressure, DWV |
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锻铁 -
WROUGHT IRON - |
压力
Pressure |
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软钢（低碳钢） -
MILD STEEL - |
消防，防火
Fire Protection |
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铝 -
ALUMINUM - |
制冷，灌溉，某些太阳能
Refrigeration, Irrigation, some Solar |
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镀锌钢 -
GALVANIZED STEEL - |
压力，排水、排渣与放气
Pressure, DWV |
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锌 -
ZINC - |
涂层，衬料，某些管件
Coatings, Linings, some Fittings |
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镁 -
MAGNESIUM - |
热水器阳极，管线的阴极保护
Water Heater Anodes, Cathodic protection for
pipelines |
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阳极（-）主动；贡献材料
ANODE (-) Active; Sacrificial Material |
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| 5. |
脱锌现象是一种类型的腐蚀，黄铜作为合金溶解成铜元素，然后从溶液中在作为金属沉积在黄铜表面，但是这种沉积却是多孔渗水的。锌元素可能从黄铜中分解出来以可溶解盐方式被带离，或者可能以无法溶解化合物方式沉淀在某个地方。脱锌现象通常发生在锌含量超过15%的黄铜阀门上。一般来说，在应力较高的区域，例如阀门阀杆和闸阀阀体，是受到脱锌现象危害的主要地方。
Dezincification is a type of corrosion in
which brass dissolves as an alloy and the copper constituent redeposits
from solution onto the surface of the brass as a metal, but in the
porous form. The zinc constituent may be carried away from the brass
as a soluble salt, or may be deposited in place as an insoluble compound.
Dezincification is normally associated with brass valves where the
zinc content exceeds 15%. Generally, areas of high stress, such as
valve stems and gate valve bodies, are primary targets of attack. |
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| 6. |
在个别情况下，存在着由侵蚀性水导致的腐蚀，这种腐蚀可能会由于设计问题或制造工艺问题而变得严重。导致蚀损斑的侵蚀性、硬质井水可以通过化学分析鉴别出来，然后通过处理使其化学成分限制在可接受的范围。典型例子是这些硬水具有很高的溶解总固体含量，包括硫酸盐和氯化物，pH值在7.2至7.8之间，二氧化碳气体含量高（百万分之十以上），还存在溶解氧气体。软酸性水可能会使固定装置出现令人头疼的绿斑现象或导致“绿水”现象。将这种水的pH值提高到7.2或更高，通常即可解决这种问题，但是应该咨询有资格认证的水处理专家。
On rare occasion problems of corrosion by
aggressive water, possibly aggravated by poor design or workmanship,
do exist. Aggressive, hard well waters that cause pitting can be identified
by chemical analysis and treated to bring their composition within
acceptable limits. Typically these hard waters are found to have high
total dissolved solids (t.d.s.) including sulfates and chlorides,
a pH in the range of 7.2 to 7.8, a high content of carbon dioxide
(CO2) gas (over 10 parts per million, ppm), and the presence of dissolved
oxygen (D.O.) gas. Soft acidic waters can cause the annoying problem
of green staining of fixtures or "green water". Raising
the pH of such waters to a value of about 7.2 or more usually solves
the problem, but a qualified water treatment specialist should be
consulted. |
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| 7. |
侵蚀性土壤环境可能是铜管系统外部腐蚀的一个原因。不一致的土壤特性，例如不同的土壤透气性，电阻系数，或吸湿性，在相邻的管道部件之间可能产生电化腐蚀单元。土壤中包含的氨，氯化物以及氮与水结合形成酸。任何金属管道铺设在灰或煤渣中都会受到其中的硫磺与水结合所产生的硫磺酸的侵蚀。
Aggressive soil conditions can be a cause
for external corrosion of copper piping systems. Non-uniform soil
characteristics, such as different soil aeration, resistivity, or
moisture properties, between adjacent sections of tube can create
galvanic corrosion cells. Soils containing ammonia, chlorides, and
nitrogen are known to combine with water to form acids. Any metal
pipe laid in ash or cinders is subject to attack by the acid generated
when sulfur compounds combine with water to form sulfuric acid. |
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