Task
Execution of upgrading and engineering measures on negative safety valves and designing of pneumatic anticipatory control valves in co-operation with RWE Power AG/MHKW Karnap. Including a short downtime, the implementation of the new anticipatory control valves and upgrading of control cabinets was to be conducted within a timeframe of less than 4 days, as requested by RWE Power AG.

Preparation
The refuse-fired power plant at Karnap, owned by RWE Power AG, had six negative safety valves installed. These safety valves were fitted with three anticipatory control valves, which protected the system against excess pressure. In accordance with AD 2000 (Technical Bulletin A2) this implied a safety selection one out of three. The anticipatory control valves were fitted with electrical eccentric slider-crank actuators and magnet plungers. Due to the long operating period of the plant the number of operational failures had increased during the last years considerably. Because of these disruptions and difficulties to procure spare parts RWE and KSB explored the possibilities of upgrading the system to modern anticipatory control valves. To safeguard plant operations the original control valves (electromagnetic controls) were examined and it was decided to upgrade the system to pneumatic anticipatory controls on the basis of the standard valves KSB Nori© 500. Decision-making included exploring the following points:

• Easy assembly of anticipatory control valves
   KSB Nori© 500.
• Long-time secure and efficient spare parts
   procurement.
• Comparably little time and effort on the
   piping system to install the valves.
• Control cabinet can be retained, simply
   exchanging the switchboard.
• Pressure line and pressure sensing line don't
   have to be changed.
• Order of monitoring devices does not have
   to be changed.
• Cost-efficient solution.
• Unaltered verifying function.

Contractor
KSB Service GmbH is the services subsidiary of KSB AG, founded in 1871 and today a global manufacturer of pumps, valves, and custom-made all-in-one solutions for the areas of industrial applications and water technology, energy and facility technology. World-wide, more than 1,600 service specialists take care of the complete life-cycle of products – rotating equipment and valves – to enable their continuous availability. KSB offers custom-made service solutions for assembling and commissioning equipment, furthermore maintenance and repairs, even offering complete overhauls, upgrading and integrated service packages, on request at a fixed price. Service certificates for power plants (KTA) and industrial processing plants (SCC**) are most important safety operations issues. In the year 2005 KSB AG had 13,000 employees and posted sales of € 1.39 billion.

Internet
http://www.ksb.de

Brief Description

• Risk analysis, project engineering and upgrading measures regarding six negative safety valves in the refuse-fired power plant Karnap/RWE Power AG. 
• Construction of modern pneumatic safety valves. 
• Maintenance services for the negative safety valves (main valve). 
• Installation of new pneumatic control valves within a restricted timeframe of four days per safety station.
• Measures to reduce spare parts stockpiling.
• Upgrading of control cabinets to modern instrumentation and control systems. 
• Compiling of technical documentation for the expert's report by RWTÜV.  

Customer's Benefit

• Optimisation of technical complex special fittings and stations. 
• Increasing availability of plant operations and increasing plant safety. 
• Lowering of maintenance costs. 
• Optimisation of spare parts stockpiling.
• Retention of existing peripheral equipment and testing operations.
  

In-depth Study
Click here to download an in-depth study in PDF format 
 

Return to overview case studies