solution extends the service life of older profilers and reduces the cost of maintenance. Moreover, the retrofit with new, improved actuators can be done at a considerably lower cost than a complete rebuild of older actuators. A major European newsprint manufacturer has seen the benefits. A steam profiler, installed in 1999, was showing its age and many of the actuators were failing regularly in the high temperature environment. Their replacement was a maintenance burden every six months when the profiler was taken out and overhauled. The 114 obsolete actuators were replaced in-situ with new bolt-on actuators that had been designed to perform reliably at high temperatures. The new Tasowheel STA-1015 can replace old model electromechanical steambox actuators types (EMA15, EMA1000 and STC900). The customer noted that the new actuators fitted perfectly with the same, originally-installed connections and gaskets. OVERHAULS EXTENDED The customer reports that the replacement cost was considerably less than alternative solutions since no original-design replacement actuator was available. Overhaul of the entire old actuator set was possible but would have required considerable downtime, manpower and lost production. With the reliability problem solved, the mill staff extended the steam profiler overhaul cycle to two years from the previous six months. This means lower maintenance costs and a longer lifetime with better reliability for the profiler. CASE STUDY 6 ZONE-BY-ZONE While some papermakers opt for a one-shot replacement of all actuators, some have replaced them gradually, thereby spreading the costs over a longer period. In the Zone-by-Zone method, CD profiling actuators and dilution valves can be replaced individually or many at a time. This flexible solution allows pulp and papermakers to gradually modernise their system and only replace what is necessary and when. This can extend the lifetime of the CD profiling system and help keep their budgets in check. Papel Aralar, a manufacturer of specialty paper in Amezketa, Spain, decided to take adopt this strategy whilst renewing the old CD actuators and dilution valves in one of their machines. As is common nowadays, the original spare parts were no longer available; furthermore, renovation was not practical and more costly. As a first step, two new actuators and valves were installed. After testing the new actuators under real circumstances for a couple of months, the customer ordered a change of the next 25 actuators to be made at the turn of the next year. This gradual approach is also suited to situations where the electronics need updating but the mechanics of the actuators are still in good shape. An electronic upgrade can sometimes satisfy both need and budget! Figure 6. New Tasowheel STA -1015 actuators. During the latter part of 1990s the market for steam profilers was at its peak, but many of those original investments are now starting to show their age WORLD PULP&PAPER 47