Mythbusters: It takes longer to install a Superbolt (MJT) than the solution you already have
The Myth: It takes longer to install a Superbolt (MJT) than the solution you already have.
The Truth: If only the time to turn or stretch an individual fastener is considered, other methods appear to be faster. However, if handling of heavy hydraulic equipment is considered, which often requires two workers to operate, it is much faster to mount MJTs in terms of man hours. An M48 Superbolt tensioner can be tightened in only 90 seconds with a standard manually operated torque wrench. Large MJTs can be tightened with pneumatic torque wrenches very quickly.
Example: (18) 5”-8 tpi (approx 130 mm diameter) MJT’s were tensioned on a boiler feed pump in 2-1/2 hours versus 10-12 hours with the old method using large hydraulic wrenches. MJTs tighten in pure tension and eliminate thread galling which causes damage and delays. Since only simple hand tools are required, no crane time or large tool sharing is needed, allowing several workers to install multiple MJTs at the same time.
