As safety requirements for the equipment of pressurized hot-water and steam installations and the associated facilities become increasingly stringent, Flowserve Gestra is responding accordingly. Complying with new and updated technical codes, Gestra will present two new safety systems, both of which will be on display at their stand.
Gestra will present two new level-limiting systems for the equipment of pressurized hot-water and steam plants: the NRG 1-50/NRS 1-50 for low levels, and the NRG 1-51/NRS 1-51 for high levels. Both products are approved according to EN 12952-11, EN 12953-9 and the VdTÜV bulletin “Water Level 100”. The units are certified to the SIL 3 requirements of IEC 61508.
The new level limiters offer several features that improve the functionality and ease of use of these products. With accessible, removable connection terminals, taking measurements is quick and easy. The units are supplied with 24 Vd.c. power, making them independent of different grids and suitable for secure battery networks without requiring additional components. 230 V 50–60 Hz and 115 V 50–60 Hz versions are also available. For increased precision, the measuring range can be adjusted over >10 to >0.5 μS/cm. Only one control cabinet and one controller is necessary for the two limiter electrodes.
The new level-limiting systems are set to launch in August 2009, while old units will be removed from the product range by the end of 2010. This innovation will initially have no effect on existing plants, though for new plants, the approval number will not be extended.
Gestra will also present a new conductivity-measurement system, which comprises the LRG 16-9 conductivity electrode with an integrated Pt100 resistance thermometer and LRS 1-7 conductivity switch. The system monitors the returned condensate of steam systems for the ingress of foreign matter. It is approved on the basis of “Water Monitoring 100” and supplements the TÜV-tested conductivity-measurement equipment for monitoring condensate returns.
Following the introduction of their electrode systems, Gestra integrated a two-electrode unit into a system for the monitoring of condensate, feedwater, cooling water and steam regeneration, resulting in this new conductivity-measurement product. The two-electrode system is well suited for installation in pipes, and can be mounted in an existing 1⁄2-in. coupling sleeve, or alternatively in measurement chambers or mounting flanges. The electrodes are designed for use up to a pressure rating of PN 40.
The LRS 1-7 conductivity switch has two volt-free relay contacts to actuate a three-way control valve or continuous blowdown valve, as well as to signal alarms or drive a solenoid valve. If actuating a continuous blowdown valve (which is achieved through a two-position controller), a purging interval can be set to act independently of the conductivity level.
An electrically isolated 4–20 mA current output is also available as an option. Referred to 25°C, the measuring range extends from 0.5 to 10,000 μS/cm. The system features a four-digit, seven-segment display that provides a visualization of the realtime temperature-compensated conductivity. The unit provides IP 65 protection and is available with preconfigured cables with plug-and-socket connections for easy installation.
The system can alternatively be arranged by connecting the conductivity electrodes to the LRS 1-7 switch. Then, the temperature compensation can then be implemented through an external resistance thermometer.
Gestra AG, Bremen, Germany
Hall 8, Stand U17 – V22