Grout Diverter Station

The ROV Grout Diverter Station uses an ROV to connect a flexible-hose umbilical to a rotary selector valve station mounted on the jacket at some point near the tops of the pile sleeves. The inflatable-seal stinger described on the previous page is also used with this system. The GDS system minimizes ROV and vessel moves and expedites the grouting operation, so it is typically recommended for structures having four or more pile sleeves at depths greater than 500 ft (152 m).

The rotary selector valve has up to nine outlet ports to accommodate up to eight grout lines and one flush line. The only moving part is the valve rotor, which is easily operated by the ROV. Check valves at the entrance of each port prevent grout back flow into the selector valve.

The station typically incorporates a grout packer inflation manifold, as shown in the illustration at right. The inflation manifold comprises ROV-operated valves and pressure gauges that allow packer inflation pressure to be monitored by the ROV. This arrangement totally eliminates lines to the surface.

Advantages
   • Minimizes grout equipment weight

   • Minimizes ROV movement and umbilical

     deployment

   • Eliminates all fixed lines from the

     surface

   • Cuts structure fabrication and

     installation cost

Contingency Systems
Secondary packer inflation and grout injection is typically via stabbing receptacles mounted on each pile sleeve. These receptacles are similar to the one on the Grout Diverter Station.

Operation
The ROV guides the stinger into the receptacle on top of the station. Nitrogen or compressed air supplied through the umbilical inflates the stinger seals, locking the stinger in place and isolating the packer-injection port.