Final acceptance – Is carried out before delivery to the customer depending on the classification of the pressure equipment. Here, pressure equipment is to be subjected to the acceptance process as described below.
a) Final inspection
Pressure equipment must be subjected to a final inspection, where a visual inspection and test of the related documentation is to be carried out in order to check that the requirements of this guideline are fulfilled. In doing so, inspections carried out during manufacturing may be taken into account. If required for safety reasons, the final inspection of the inside and outside of all parts of the equipment must be carried out during the manufacturing process (e.g. if testing during final inspection is no longer possible).
b) Pressure test
The acceptance of the pressure equipment must also include a pressure strength test which is normally carried out in terms of a hydrostatic pressure test where the pressure for this is clearly specified. For equipment of the category I manufactured in series this inspection can be carried out on a statistical basis. If the hydrostatic pressure test is disadvantageous or infeasible, other tests can be carried out which have proven effective. For tests other than the hydrostatic pressure test, additional measures such as non-destructive tests and other equivalent procedures must be used first.
c) Testing safety equipment
For components, the acceptance must also comprise a test of the equipment parts with a safety function, whereby it must be tested that the requirements have been fully satisfied.
Flooding point/flooding speed – The term flooding point refers to the speed at which droplets can no longer fall down and are pressed through the knitted wire of a demister. If the flooding point is not exceeded the formation of secondary droplets is prevented, too.
Flow cross-section – When reacting, a bursting disc frees a cross-sectional area for discharging the medium. The required free cross-section partly depends on the medium, the particular construction of the bursting disc, the bursting pressure, the temperature and the volume to be discharged and is determined on an individual basis for each specific application. Considering all these parameters, the minimum nominal size of the bursting device can be determined for each single application.
Flow rate – The flow rate (or flow velocity) is a physical size and defines the speed in a flow, in a directed movement of particles or in continuous bodies (liquids).
Flow velocity=(Volume flow )/(Area of pipe cross-section)
The flow rates of the individual particles are differentiated from the medium flow rate using a vector line element, a surface element, a volume element or a time interval. The flow rate is the spatial change of a single point along its trajectory. Medium flow rates can be determined for instance via the flow cross-section, the flow rate or a flow line. In literature, the flow rate is specified in a variety of ways. It is known under the symbols ω (small Omega), ν and c.
Alongside the viscosity the flow rate is an important factor influencing pressure loss and thus flows into the calculations for static mixers, demisters and heat exchangers.
Forward acting rupture disc – Bursting discs are pressure relief devices protecting a vessel or a system from damaging high or low pressure by making a disposable membrane burst. Bursting discs consequently act as a type of predetermined breaking point. STRIKO process technology disposes of a comprehensive range of bursting discs and differentiates for instance between forward acting and reverse acting rupture discs. STRIKO forward acting rupture discs are aligned with the concave side to the process medium, i.e. the bulge of the bursting disc points away from the process. If the process pressure exceeds the permitted operating pressure the tensile strength of the material is reached; the disc bursts. In the production of forward acting rupture discs, STRIKO process technology also uses ultra-modern, laser-based production technology. Forward acting rupture discs made of metal of the STRIKO series SZ-X are installed in the standard holder SHZ or in the pre-loaded holder SHZ Pro between flanges. They are particularly suitable for safeguarding medium to high working pressures, can be used as sole pressure safety protection or in combination with a safety valve, dispose of a fragment-free opening behaviour, are suitable for gases, steams and liquids and are available in various materials such as high-grade steels, nickels and special materials such as Hastelloy® or Tantal. Alongside a multitude of design options the forward acting rupture discs made by STRIKO can also be combined with an optional burst indicator installed on the discharge side.
Fouling – Refers to general contaminants / impurities. In relation to the heat exchanger, fouling may occur in the jacket area (heating medium) and in the product tubing. Particularly when tempering viscous media (e.g. cooling silicon), fouling may occur as the dynamic viscosity (flowability) of the medium to be tempered increases exponentially as the temperature drops. Fouling inside the product tubing of heat exchangers can be counteracted by using the patented STRIKO S-Helical technology. Fouling reduces the heat transfer and in turn the efficiency of heat exchangers.
Fragmentation – The term fragmentation refers to the area characteristic of a bursting disc upon reaching the burst pressure. Depending on various factors, bursting discs may open with or without fragmentation. Due to the material, STRIKO graphite bursting discs e.g. always open with fragmentation. For multilayer STRIKO metal bursting discs, the area characteristic depends on the pressure and temperature at which the discs are used.