Split Case Turbine

Problem: The awkward bolting of this turbine amplifies the difficulties of the traditional hot bolting method. It previously required 30-45 minutes per stud to tighten using heating rods. Workers complained of the safety hazard of the heating rods and the time and effort for the bolting process.

Solution: Utilizing small air impact tools and hand torque wrenches, the entire turbine is bolted in under 4 hours at a leisurely pace. The management of the company timed the installation for each size, start to finish, for 1 worker. Following the current Superbolt® procedure, air impact tools were used for most of the tightening of the jackbolts. Final calibration is done with the hand torque wrenches. The times were as follows:

2" size: 1-2 minutes
3" size: about 3 minutes
3-1/2" and 4" size: 4-5 minutes

Keep in mind, with Superbolt® products, multiple workers can work simultaneously if room permits. This can be very valuable if the turbine work goes over schedule and unit generation is being lost.

With Superbolt® products and enough workers, it is possible to bolt or unbolt even the largest steam turbines in only a couple of hours!