Electricity + Control February 2018

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CONTROL VALVES + ELECTRIC ACTUATORS

Automatic flow regulating valve regardless of fluctuating inlet pressure. The principle is impressive, yet uniquely simple. The constant flow is generated by two stainless steel spring plates of the reg- ulating orifice, riveted together across each other, and which, depending on the differ- ential pressure, open or close to a greater or lesser extent the ring or regulating fun- nel thus created. For the most extreme differential pres- sure (around 10 bar) the flexible regulating orifice is in complete contact with the regu- lating funnel so that only the rivet hole cross section is available for flow and from this point the valve operates as a fixed orifice. The REG flow limiter can be used wherev- er a constant flow rate is required despite pressure fluctuations in the system, for ex- ample switching a consumer unit on and off. Notable Benefits • No auxiliary power required

• Reliable - no wearing parts • Energy-saving • Easy to fit

What usually happens when several ho- tel guests all start to shower at the same time? The water temperature suddenly changes from pleasant to horribly cold or unbearably hot! Sometimes there is less water flowing sometimes there is more; the day has hardly begun but it starts with a basically avoidable annoyance. It would be avoidable, if the planners had thought beforehand to install Kobold’s REG flow restrictors/regulator that keeps constant quantities of liquids in pipework systems. The REG rate regulators are ideally suited for the simple restriction to a preset value of throughputs of water, or of liquids similar to water. The flow restrictors ensure equilibri- um, particularly in systems with many users and resulting pressure fluctuations caused by random flow conditions. In other words, the desired throughput is not exceeded. The REG valve operates without pow- er supply, keeping the flow rate of fluids constant with great accuracy (± 0,2 L/min) PED Certified The South African valve manufactur- er AZ-Armaturen South Africa has been successfully certified according to the Pressure Equipment Directive (PED) 2014/68/EU − Module H. This is a great achievement for the South African production plant of the AZ-Armaturen Group. Valves manufactured by AZ-Ar- maturen South Africa which are in ac- cordance with the PED requirements, can now be affixed with the internation- ally recognised ‘CE’ mark. The Pressure Equip-

So, it is not only in the sanitation and heat- ing fields that unwanted fluctuations in flow and temperature occur, but also in many areas of general industry and plant construction. Kobold’s REG valves are avail- able in brass and stainless-steel.

Enquiries:Tel. +27 (0) 10 595 1831 or email sales@instrotech.co.za

• Easy to assemble • Compact design

New detonation flame arresters Now available in Southern Africa through EnergasTechnologies , is a new, innovative range of detonation flame arresters from leading US-based manufacturer, Protectoseal, which sets a new era with its ability to act as a deflagration and detonation flame arrester simultaneously. The new Protectoseal Series 26000E/ 36000E bi-directional overdriven/ unstable detonation arresters, now available in southern Africa through EnergasTechnologies, effective August 2017, usher in a new era in flame arrester technology with their versatility, allowing them to withstand both deflagration and detonation flame fronts. Deflagration and detonation are two forms of combustion. If the combustion process propagates outward at subsonic speeds and pressures less than 0,5 bar, it’s a deflagration. If the explosion moves outward at or above the speed of sound (343 m/s), it’s a detonation. On the other hand, a detonation is a dramatic, often destruc- tive form of an explosion. Detonation is divided into two types: Stable detonation and unstable detonation. Stable detonation is characterised by the speed of sound, while unstable detonation is characterised by supersonic speed in excess of the speed of sound and up to 2 000 ms with significant overpressure of up to 40 bar. In piping applications, selecting the right flame arrester – whether for deflagration or detonation – often involves the trouble of determining the probable type of combustion, location and other factors. “The beauty of our new Series 26000E/ 36000E bi-directional overdriven/ unstable detonation arresters is that the flow and pressure drop performance for these units are extremely competitive compared to other manufacturers’ devices,” says Lavenda Sekwadi, Process Engineer at Energas. “Protectoseal’s Series 26000E / 36000E detonation flame arresters are designed to withstand deflagrations, as well as stable detonations overdriven/ unstable detonations. These arresters are bi-directional, capa-

ment Directive reg- ulates the manufac- turing of Pressure Equipment such as pressure vessels, pip- ing, and valves within the

European Union. Globally, PED has be- come the most recognised standard for pressure equipment.The certification to Module H refers to a Full Quality Assur- ance System including the design of the valves under the scope. Enquiries: Tel. +27 (0) 11-397-3665 or email info@az-armaturen.co.za

ble of stopping a flame or detonation approaching from either direction of a piping system,” adds Sekwadi. Available in sizes from 2 inches (DN50) to 12 inches (DN300), the new range has a maximum operating pressure of 1,22 bar and maximum operating tem- perature of 60ºC.

Enquiries:Tel: +27 (0) 11 397 6809 or email lavenda@energas.co.za

Electricity + Control

FEBRUARY 2018

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