AMTEC Newsletter July 2015
Dear Reader,
since we are experiencing these high summer temperatures in Germany, it seemed like a good idea to introduce our high-temperature equipment; the for gasket testing at temperatures up to 900 °C (1,650 °F). In addition we also want to tell you about our comfortable and simple assembly procedure of stuffing box packings using our hydraulic system TEMESstb.ctrl which has been is successfully applied in the industry for many years.
In this newsletter, we want also to inform you about our latest experiences with the revision of the calculation method for of flanged joints according to EN 1591-1.
Have fun and gain new insights with these and other news items from AMTEC!
Your AMTEC team from Lauffen, Germany & West Conshohocken, PA, USA
high temperature test rig

high temperature test rigHigher, faster, further - this seems to apply to many situations in daily life. The same applies for all of the sealing elements, especially for higher temperature testing The operating temperatures, for which gaskets are required, are exceeding the usual limit of 400 °C (750 °F) from previous years. For future highly efficient power plants or for molten carbonate (MCFC) and solid oxide (SOFC) fuel cells, temperatures above 700 °C (1,300 °F) are now seen as a more realistic application area.
For this temperature range it’s been is important to determine in research projects not only the long-term behavior of metallic materials for pipes and forgings, but also new demands on the sealing technology have to be identified.
AMTEC has developed the multifunctional testing equipment TEMESfl.ai1 for gasket testing, in which sealing elements can be examined up to a temperature of 600 °C (1,100 °F). Deformation, recovery (elasticity) and creep/relaxation properties can be determined in this test rig in standardized test sequences. For higher temperatures, there is now a new testing machine available: The high temperature test rig
For this new test device, the heating power of the test modules was increased to 2.7 kW, and the insulation between the test platens and the rest of test stand, as well as the thermal shield to the environment, have been completely revised. With this new configuration now test temperatures of 900 °C (1,650 °F) can be achieved. The maximum axial load remains at 1000 kN (225,000 lbf) and the maximum internal pressure for leakage tests is still 200 bar (2,900 psi).
Are you interested in such a test machine? If not we offer you testing in our accredited laboratory as a service. Please send your inquiry to TEMES, we will contact you immediately.
EN 1591-1

Fatigue SeminarSince two leading German software providers have expressed themselves very critically or by refusing to use the new version of EN 1591-1 (issue December 2013) for their customers, it is time to put some things back in the right light.
The new edition of the standard was jointly developed by various standard committees as a compromise to bring different existing flange calculation standards in consistency. The EN 1591-1 should be the basis for all other European rules in this case, i.e. the annexes in EN 13445-3 (Unfired pressure vessels) or EN 13480-3 (Industrial piping) should have only references to the EN 1591 -1, but do not include their own calculation procedures anymore.
Since the new standard has been issued, it has been discovered that some of the modifications can cause, in certain applications, significant differences to the old standard. This relates primarily to the following points:
  • Use of the additional deformation ΔeGC instead of the creep /relaxation factor PQR: For gaskets with low PQR value it can happen that a significantly higher bolting force is required so that the creep or relaxation of the gasket do not lead to an impermissible high unloading in the later operating conditions.
  • •Lower permitted plastification of the components: If the assembly condition is determinative for the maximum permissible forces, no differences in the results will occur. But if this is an operating condition, the allowable bolting force can (but need not) be lower within the new standard. This has to be proved in each application case.
  • •Consideration of lateral forces and torsional moments: In order to consider the counterbalance to the shear loads, friction factors between gasket and flange face surfaces are required. These factors are currently limited available, and published literature values should be regarded as very conservative. But in many cases no detailed pipeline statics are existent, therefore equivalent external forces and moments (i. e. additional internal pressure, additional loads as per EN 1092-1, etc.) are treated in the calculation, whereby nothing will change in the calculation results.
In summary, it must be noted that differences in the calculation results cannot be excluded and that they are mostly restricted to individual types of gaskets. Moreover, in any case the new standard provides conservative results, an overstressing of the components cannot be caused by the new algorithm.
We therefore advise our customers to use the new edition of EN 1591-1. In our software there is the option to switch to the calculation algorithm of the old standard in order to compare the results with each other. This will give you the necessary confidence in dealing with the new version of EN 1591-1.
You can learn more details on the standard EN 1591-1 in our training workshops, in which we explain the theory of the standard as well as practical examples of industrial applications. The next training course is scheduled on September 14 & 15, 2015, during the Heilbronn Wine Village, the largest and most popular wine festival in the region.
 » More . . . 
assembly of packing rings

hydraulic clampingThrough the new edition of ISO 15848-1, the tightness of the stem seals has gained further importance. The ISO standard describes the way valves have to be classified and ultimately also have to be branded. In addition to the operating temperature and the mechanical cycles (number of spindle movements), the tightness of the housing cover, and the stem seal, plays a decisive role in the classification procedure.
The valve manufacturers are thus obliged to use high-quality sealing elements in order to achieve a correspondingly good tightness classification. Unfortunately, the importance of assembling the packing sets is often ignored or at least underestimated. AMTEC has carried out extensive investigations for over 20 years ago and developed a method for the installation of packaging rings using a hydraulic system.
Using this method, a good adaptation of the packing materials is achieved on the housing wall or to the spindle; the packing rings are uniformly deformed in itself, and also creep behavior can be anticipated by a higher pre-deformation in comparison to the later pre-stressing of the packing rings at the end of the assembly procedure. The use of disc springs, so called live loading systems, is thus superfluous in most cases.
The long experience in the nuclear industry can now also be applied in other industries, because our method is used in order to achieve the highest defined tightness class AH when the valves are tested according to ISO 15848-1.
A hydraulic pump, two hydraulic cylinders with matching tension nuts, hydraulic hoses and a manometer are all you need to install stuffing box packings for highest tightness requirements! And with the modular design of the cylinder, virtually all types of valves can be assembled hydraulically with a few different cylinder sizes and the associated tension nuts.
In addition to the hardware TEMESstb.ctrl, we also offer the assembly of your valves with our equipment on site as a service.
 » More . . . 
dates of training courses

    Assembly of bolted connections: EN1591-4

  • September 7, 2015 (German)
  • October 15, 2015 (German)
  • December 1, 2015 (German)
    Calculation of Bolted Flange Connections: EN1591-1
  • September 14 & 15, 2015 (English)
  • September 16 & 17, 2015 (German)
  • March 8 & 9, 2016 (German)
    Keeping fatigue low for LTO
  • October 20 & 21, 2015
 » More . . . 
contact us
AMTEC Advanced Measurement
Messtechnischer Service GmbH
Hoher Steg 13
74348 Lauffen
Tel.: +49 7133 9502-0
Fax: +49 7133 9502-22
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AMTEC North America, Inc.
Four Tower Bridge
200 Barr Harbor Drive, Suite 400
West Conshohocken, PA 19428
Tel.: +1 610-941-2751
Fax: +1 610-941-2990
» Email AMTEC NA» Website
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