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Heat exchanger tubes are made using the cold rolling process and the semi-finished product for these are used rolled steel tubes. Heat exchanger tubes are used in energy and chemical industry for heating the buildings, water etc. The heat exchanger tubes make it possible to transfer thermal energy from one media to another. The heat transfer may be linked with phase transformation of the media. Overview of the dimensional standards and the technical-delivery conditions according to which these tubes are manufactured and supplied is shown in aseparate overview.
Dimensions of the heat exchanger tube
The outside diameter of the heat exchanger tubes ranges from *6 mm to *1 mm according to DIN ****0 and from ½ inch (*2.7 mm) to 4 inches (**4.3 mm) according to ASTM A**9 The tubes for the heat exchangers may be supplied also in compliance with other standards starting with 4 mm. Detailed overview is shown in tables and according to BS, NF A, UNI, STN, ČSN, GOST standards, according to EN ****6 and according to JIS standards. 
Types of steel for heat exchanger tubes
Tubes for the heat exchangers are made of the following steels according to EN ******2: P**5GH, according to DIN ***9: St *7.0, DIN ****5: St*5.8, *5Mo3, DIN ****3: TTSt*5N and according to ASTM A**9. Additional types of steel according to BS ***6, NF A *****5, UNI ***2, GOST **0, GOST ***0, JIS ***1, JIS ***2, STN *2 ***1 and ČSN *2 ***1 together with its chemical composition and mechanical properties are shown in a separate overview. Steel is manufactured in electric arc furnace and it is killed. Other types of steel are possible to deliver upon request.

Delivery condition and tubes surface of the heat exchanger tube
Tubes are supplied according to agreed standards. The cold drawn tubes after the final forming go through thermal processing in shielding gas normalizing.

Tubes length destined of the heat exchanger tube
Upon request the heat exchanger tubes may be supplied in length up to *8.3 meters.

Straightness of heat exchanger tube
Straightness deviation for the whole length of a tube L can not exceed value of 0.***5 x L. In conversion to the 1 meter length it can not exceed 3 mm. 

Ends of the heat exchanger tube
The ends of the tubes are vertical to the longitudinal axis and are without burrs.

Marking of the tubes and tube bundles
Tubes are marked by spraying the agreed upon data. Tube bundles are marked with labels with the agreed upon data.

Surface protection of the heat exchanger tube
The inner and outer surface is protected by a light oil application. Upon request it may be protected with and easy removable oil application on the outer side. The tube ends may be enclosed by a plastic plug.

Packaging of the heat exchanger tubes
The tubes are usually packaged into bundles of a hexagonal cross-section and are bound with a steel band that has a paper underneath. The package is wrapped with a plastic sheet. Upon request the tubes may be supplied in wooden crates.

Testing of the heat exchanger tube
Besides the prescribed mechanical tests, each tube is tested with leak tightness test by eddy current. Based on an agreement it is possible to do the hydrostatic testing or ultrasound testing.

Certified test reports
EN ****4 2.2, 3.1 or 3.2
ASTM/ASME A**0
DIN ****9 2.2, 3.1.B