What is the current standard for copper fittings?

EN 1254 Parts 1 to 5.

Il verderame che si forma all'interno delle tubazioni per l'acqua potabile è dannoso per la salute?

No. Innanzitutto bisogna chiarire che quello che si forma nelle tubazioni non è verderame: l’equivoco nasce dal fatto che numerosi sali di rame hanno una colorazione verde o verde-azzurra.
Il verderame, che si usa in agricoltura, è oltretutto solubile in acqua quindi non potrebbe restare sulle pareti interne del tubo.
Qui si forma un sale di stechiometria non definita composto da numerosi anioni, che è protettivo, resistente e non dannoso per la salute umana.

Miedziane solarne sysytemy grzewcze

Publikacja przedstawiająca w skrócie proces projektowania i montażu miedzianych instalacji grzewczych.

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Why is copper so efficient in heat exchanger applications?

Because the thermal conductivity is so high – it is 23 times better than stainless steel or titanium and 1.6 times better than aluminum.

Korrosionshärdighet hos koppar i kontakt med olika kemiska ämnen

Korrosionshärdighet hos koppar i kontakt med olika kemiska ämnen

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Milyen tisztítást igényelnek a rézötvözetből készült ketrecek?

A rézötvözet-háló természetes módon gátolja a biológiai szennyeződés kialakulását, ezáltal javul a vízcsere és cirkuláció, a víz oxigén szintje magas marad, ami blokkolja a paraziták és patogén kultúrák fejlődését, azok nem fertőzik a halakat. Ezáltal csökkenthető a felhasznált antibiotikumok mennyisége, algagátló (antifouling) vegyszerek alkalmazása és a költséges ketreccsere. A rézötvözetből készült ketreceket átlagosan évente egyszer vagy kétszer kell tisztítani, ami lényegesen kevesebb, mint a hagyományos ketrecek esetében, főleg ha a számot az teljes élettartamra vetítjük.

Miedziane szyny zbiorcze - wytyczne projektowania i instalacji

Najnowsze wydanie popularnego podręcznika “Miedziane szyny zbiorcze. Wytyczne projektowania i instalacji” (ang. Copper Busbars: Guidance for Design and Installation) w wersji anglojęzycznej.

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What is the difference between a voltage regulator and a Dynamic Voltage Restorer (DVR)?

Both are used to mitigate the effects of voltage dips. Dips are characterised by the depth – the retained voltage – and the duration. Short and deep dips are best served by a DVR while long and shallow dips are the province of the voltage regulator.

A voltage regulator has no energy store. It has a transformer secondary winding in series with the supply. When the input voltage moves outside the tolerance band the primary of that transformer is driven to boost, or in anti-phase to reduce, the voltage appropriately. Because the load voltage is kept constant, the power to the load is constant so, when the input voltage falls, the input current increases. The current capability of the supply and the device itself limits the working range to about +/-30% of nominal voltage.

A DVR has an energy store, so requires no additional input power (in the short term) to boost the voltage during a dip. A DVR can correct a dip to 0% retained voltage. But the DVR has a limited energy store and so is suitable for short-term effects only – it cannot correct for long term under voltage, for example. Also, the store has to be recharged between events so it is not suitable multiple dips are expected frequently. Typically, DVRs use super capacitors, large secondary batteries or high-speed flywheels as energy stores.

Unsurprisingly, DVRs are more expensive than voltage regulators.

In long strip roofing what is the maximum length of a bay?

This depends on the pitch of the roof. For 3-4 degrees 14.6m, for 4-10 degrees 11.0m, for 10-30 degrees 9.7m and for over 30 degrees 8.1m.

Why is copper the preferred material for busbars?

There are several reasons. Firstly, the bars are more compact because copper has a higher conductivity than aluminium. Secondly, it is much easier to joint copper. A hard, highly insulating oxide grows very rapidly on the surface of aluminium, making it very difficult to make good reliable joints in the field. On the other hand, the thin oxide layer that forms, more slowly, on copper is not an insulator so jointing is simple. Finally, copper is much stronger than aluminium, less susceptible to creep and better at withstanding short circuit current forces.

Jakość zasilania-poradnik Harmoniczne. Jak rozumieć poziomy kompatybilności

Zeszyt omawia zagadnienie kompatybilności elektromagnetycznej.

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