BS EN 13121-1:2003 GRP tanks and vessels for use above ground. Design and workmanship
BS EN 13121-1 is the European standard that gives the requirements for the design, fabrication, inspection, testing and verification of GRP tanks and vessels with or without thermoplastics lining for storage or processing of fluids, factory made or site built, non pressurised or pressurised up to 10 bar, for use above ground.
Part 1 of this standard specifies the requirements and acceptance conditions for the raw materials - resins, curing agents, thermoplastics linings, reinforcing materials and additives. These requirements are necessary in order to establish the chemical resistance properties determined in Part 2 and the mechanical, thermal and design properties determined in Part 3. Together with the workmanship principles determined in Part 3, requirements and acceptance conditions for raw materials ensure that the tank or vessel will be able to meet its design requirements. Part 4 of this standard specifies recommendations for delivery, handling, installation and maintenance of glass reinforced plastic (GRP) tanks and vessels.
The design and manufacture of GRP tanks and vessels involve a number of different materials such as resins, thermoplastics and reinforcing fibres and a number of different manufacturing methods. It is implicit that tanks and vessels conforming to this standard should be made only by manufacturers who are competent and suitably equipped to fulfil all requirements, using materials manufactured by competent and experienced material manufacturers.
Metallic vessels, and those manufactured from other isotropic, homogeneous materials, are conveniently designed by calculating permissible loads based on measured tensile and ductility properties. GRP, on the other hand, is a laminar material, manufactured through the successive application of individual layers of reinforcement. As a result there are many possible combinations of reinforcement type that will meet the structural requirement of any one-design case. This allows the designer to select the laminate construction best suited to the available manufacturing facilities and hence be most cost effective.
In considering a layered GRP structure it is assumed that it is the glass reinforcement that provides the stiffness and strength required to resist mechanical loadings. Also, since the quantity of glass reinforcement is most readily assessed by weight, the weight of glass per unit area (m) is used instead of thickness in determining mechanical properties, thus the concepts of load and modulus are replaced by unit strength (U) and unit modulus (X), these being defined in the standard.
The terms vessels and tanks as used in this European Standard include branches up to the point of connection to pipe work or other equipment by bolting and supports, brackets or other attachments bonded directly to the shell.
BS EN 13121-1 covers vessels and tanks subject to temperatures between – 40 °C and + 120 °C.
It is possible that future advances in resin technology would allow tanks and vessels to be considered for operating temperatures above + 120 °C. Should such a situation arise and a manufacturer wishes to take advantage of such developments, then all other requirements of the standard shall be maintained and such tanks and vessels shall only be designed in accordance with the advanced design method given.
Contents of BS EN 13121-1 include:
- Foreword
- Introduction
- Scope
- Normative references
- Terms and definitions
- Symbols and abbreviations
- Information and requirements to be supplied and to be documented
- Material
- Mechanical properties
- Determination of design strain and loadings
- Design
- Design analysis
- Bolted flange connections
- Supports
- Structures and fittings
- Local load analysis
- Quality control
- Site built tanks and vessels
- Marking
- Product testing for volume or batch production process
- Derivation of laminate properties from lamina properties
- Pressure and leak testing
- Methods of tests
- Approval testing of laminators
- Approval testing of welders
- Loading from local loads - Methods of calculation
- Design method for filament wound laminates
- Pre-moulded flanges technical requirements
- Shells subjected to wind loading value from metallic codes
- Horizontal vessel design
- Bibliograph
