Mechanical Design

Strength calculation

LEFFER's Engineering Department includes a special office of its own for the calculation of pressure vessels and heat exchangers to the appropriate international codes (e.g. EN 13445; ASME VIII Div. 1 & Div. 2; PD 5500; AS 1210 (incl. Supplement 1), AD-2000 Merkblätter, CODAP, etc.).

Calculation is effected to „Design by Rule“, using predominantly in-house developed programs, and to „Design by Analysis“ respectively. For the latter, the finite element program ANSYS® is used.

Design by Rule

LEFFER develops most of the calculation programs in-house. This ensures that the calculation engineers are familiar with all the details of the design concepts and backgrounds of the design codes.

This enables rapid calculation of less common designs, as are often required to meet very specific contingencies (space and/or weight limitations, compatibility of connections when replacing existing vessels). Such constraints can be sufficiently considered already at the bid stage and the customer will receive proposals for a tailor-made, while reliable, design.

It is self-evident that these programs developed in-house are subject to extensive validation by ourselves and, in addition, periodical verification by independent inspection organisations.

ANSYS is a registered trademark of ANSYS, Inc. in Canonsburg, Pennsylvania (USA).

Rechter Inhaltsbereich

Strength and Fatigue Calculation of blocking ring for Heat Exchanger

Nozzle Loads

Fatigue Calculation of Skirt-Vessel Connection

Design example: Fatigue Calculation of Skirt-Vessel Connection

Nozzle Loads

Design by Analysis

This powerful tool is finding its way into more and more international codes for pressure vessels. But long before the publication of EN 13445 and the re-write of ASME VIII Div. 2, LEFFER has been engaging in these topics and upgraded its in-house capacities to cover these calculation methods.

Due to its vast experience in this field, LEFFER is in a position to apply all design methods enabled by "Design by Analysis" (geometric linear and geometric nonlinear, elastic and plastic material laws) and thus to provide to its customers an equipment design reconciling functional optimisation with reliability regarding the strength required.

Job-related training at regular intervals guarantees now and in future that the knowledge of the engineers entrusted with these calculation methods will always be up to date.