brass flask tube

Factors that influence the choice of pipeline materials have a lot of：Process design conditions，Properties of materials、Economy、Workability，Contamination of the final product，Process Safety，Corrosion resistance, etc.。

(brass flask tube)

Classification of materials commonly used chemical pipeline

Chemical properties of the pipe material used

◆ ◆ ◆

Cast iron pipe

Ordinary cast iron pipe

(brass flask tube)

Mainly used for divination buried in the ground water mains、Gas main、Sewers, etc.，Its soil、acid、Base has good corrosion resistance。

But it's low intensity、Brittleness，So the higher pressure can not be used or toxic、Explosive medium pipe。

High pipe tubes ferrosilicon Ferrosilicon

(brass flask tube)

Resistant to corrosion of various acid，Its high hardness，Difficult process，By vibration and shock friable。Ferrosilicon is resistance to chlorine corrosion resistant tube is mainly various temperatures and concentration of hydrochloric acid。

◆ ◆ ◆

(brass flask tube)Carbon steel pipe

General corrosion intolerance，Under certain situations，Such as concentrated sulfuric acid，Lye (Room temperature)，Corrosion resistant to certain。Chlorine ions are not suitable occasion，Sensitive to stress corrosion。

◆ ◆ ◆

stainless steel pipe

Austenitic stainless steel

Austenitic stainless steel corrosion resistant steel are generally，It is the most widely used class of steel，Among them,18-8Stainless steel the most representative，It is better mechanical properties，Facilitating machining、Stamping and welding。

It has excellent corrosion resistance and good heat resistance in an oxidizing environment。But the solution containing chloride ions（CL-）Particularly sensitive media，Prone to stress corrosion。

(brass flask tube)

304Stainless steel

The most commonly used stainless steel，Containing a small amount of chromium and nickel，Very low carbon content，Easy to heat treatment。High temperature also better，The general temperature limit is less than650℃。

304Stainless steel has excellent corrosion resistance and good resistance to intergranular corrosion。Acid oxidation，In the experiment results：concentration≤65%Below the boiling temperature of the nitric acid，304Stainless steel with strong corrosion resistance。The alkali solution and most organic and inorganic acids also have good corrosion resistance。

304LStainless steel

Low-carbon version of304，Mainly for304Where the carbon steel penetration。Such that the lower carbon content in the heat affected zone near the weld to minimize carbide precipitation，And carbide precipitation may result in intergranular corrosion of stainless steel in certain environments（Welding erosion）。

321Stainless steel

(brass flask tube)

YesNi-Cr-MoAustenitic stainless steel，And its performance304very similar，However, due to the addition of titanium，It has a better intergranular corrosion resistance and high temperature strength。

(brass flask tube)

321Stainless steel having excellent high-temperature stress rupture properties and high temperature creep resistance properties，High grain boundary corrosion resistance of the applied chemical requirements、coal、Open field machinery, oil industry，Building materials, heat resistant parts and difficult parts。

316Stainless steel

Add toMo，So the corrosion resistance、Atmospheric corrosion resistance and high temperature strength in particular，Can be used under severer conditions。The excellent corrosion resistance304Stainless steel，And erosion resistant to marine and industrial atmosphere erosion。

With the addition ofMo, Therefore dilute sulfuric acid, There solution containing chlorine ions have a corrosion resistance。316Better corrosion resistance，Compare304More resistant to corrosion in high temperature environments。

316LStainless steel

316LFar lower than the carbon content316；The high amount of carbon content are the main factors causing corrosion of the intermetallic，So important conditions in the chemical industry，316La lot of uses，but316LHigh prices，316LRatio in resistance to chloride corrosion316Okay。

(brass flask tube)

High alloy content stainless steel

(brass flask tube)

Nickel content29%~30%，Chromium content in20%above，Has good corrosion resistance to acid and hydrochloric acid， Of course, more expensive。

◆ ◆ ◆

Monel tube

(brass flask tube)Nickel alloy known as Monel，Nickel is a metal base added copper、iron、Other elements from an alloy of manganese,。

(brass flask tube)

Monel good corrosion resistance，A maximum amount、Most widely、Excellent overall performance of corrosion resistant alloy。

This alloy has excellent corrosion resistance in hydrofluoric acid and fluorine gas medium，Hot concentrated alkali is also excellent in corrosion resistance。Also resistant to neutral solution、water、seawater、atmosphere、Corrosion and other organic compounds。

An important feature of the alloy is generally no stress corrosion cracking，Good cutting performance。 Temperature can go to500℃，It is more expensive than stainless steel，However, under the environment chloride，It is not sensitive to stress corrosion cracking。

◆ ◆ ◆

Hastelloy tube

(brass flask tube)

It is a nickel-base alloy，Currently divided intoB、C、GThree series，Mainly for iron-basedCr-NiorCr-Ni-MoStainless steel、Corrosive media case non-metallic material can not be used，In foreign countries it has been widely used in petroleum、Chemical industry、Environmental protection and other areas。

The main moisture chlorine、Various oxidizing chloride、Chloride salt solution、Sulfuric acid and oxidizing salt，In the low temperature acid and has very good corrosion resistance。

(brass flask tube)

therefore，Since nearly three decades、Corrosion in harsh environments，Such as chemical、Petrochemical、Flue gas desulphurization、Pulp and Paper、Environmental protection and other industries have a very wide range of applications。The earliest，Hastelloy is toHCLCorrosion developed occasions。

◆ ◆ ◆

Copper and copper alloy tube

Chemical industry, mainly made of brass(Alloy of copper and zinc)， There are bronze(Brass adding tin)， Aluminum Bronze，Copper-nickel alloy（Copper-nickel alloy）Wait。

Excellent resistance to water and atmospheric corrosion of copper alloys having，In general based medium to uniform corrosion。

Brass atmosphere，Variety of aqueous media，Organic acid has good corrosion resistance；Bronze exhibits better corrosion resistance than brass in a variety of corrosive media。

In the process of the copper alloy and the interaction with the marine environment in the atmosphere，The surface protective film can generate a passive or semi-passive state，The various corrosion inhibited。 therefore，Most of the copper alloy in the atmosphere exhibits excellent corrosion resistance。

Brass and bronze in the chemical industry mainly used in valves and fittings，There are heat exchanger tube bundle。 Copper-nickel alloy is often used in the same sea water heat exchanger bundle material。

◆ ◆ ◆

(brass flask tube)Titanium tube

Mainly used to deal with chlorine solution，Such as sea water and wet chlorine，A layer of oxide film is resistant to corrosion。Titanium material is dealingHCL，Chlorine solution，Sea water and other occasions。

◆ ◆ ◆

Polyvinyl chloride tube

Most of the most inorganic acids，Inorganic salt solution，Strong sulfuric acid/Strong nitric acid，Not applicable to most organic solvents。In most cases，PVCSuitable for wire pipelines and sewage pipes。

◆ ◆ ◆

Polytetrafluoroethylene tube

In addition to molten alkali，Fluoride，Almost all chemicals 。 Temperature can be reached250C，The linear expansion coefficient is steel10～20Multiplication；Expere，Molding difficulties，Poor thermal conductivity。

Corrosion，Aging，Low friction coefficient，Incompatibility，Wide temperature resistance。，Conveying tube that is often used in transport corrosive gases，Exhaust pipe, etc.。

(brass flask tube)

◆ ◆ ◆

FRP tube

(brass flask tube)Small density，light in mass，The quality of the glass steel pipe has only cast iron pipes.1/6，When installing the same quality pipeline，The length of the glass steel pipe is longer than the cast iron pipe6Multiplication，This greatly accelerated the progress of the construction，Save construction costs。

High mechanical strength，Excellent impact resistance，Not susceptible to impact damage； Excellent durability；Excellent chemical resistance；Environmentally with low temperature and thawing such as low temperature and thawing in the cold area，Tube does not expand and freeze，Do not produce burst accidents。

Pipe inner wall、Small fluid resistance、Sediments，Medium exercise friction loss is only steel pipe30%，The conveying efficiency is higher than the steel pipe and cement tube。

Non-conductive、Not heat，Good insulation，Good insulation，The surface of the pipe is not easy to say，So a large amount of thermal energy delivery line。

(brass flask tube)

Its raw material cost is slightly higher than the cast iron pipe and concrete tube，Close to steel pipe，But because of its many excellent features and transportation、Decrease in construction costs，Its comprehensive cost is lower than traditional pipes.。

Large diameter tube applies to buried drains、Phase tube, etc.；Small-diameter tube is excellent in resistance，Many halfway used as rain water pipes。Foreign extensive application of large-diameter glass fiber-wrapped glass steel pipe is treated as a water pipe，Replace cast iron pipe and prestressed reinforced concrete tube。

Chemical common pipeline material selection

☆A—Ability to be successfully applied

☆B—Application process should be noted☆C—Cannot be applied☆LL—Lack of information

The recommendation in the table is not absolute，Because the material is corrossed and the concentration of fluid、temperature、Compact factors such as pressure and impurities，This table can only be used as a guide。