Dual string orbital drilling system

Dual string tension - set, tension-release well packer

Dual string tubing rotator

Dual string well packer

Dual stripper assembly for slick cable

Dual subsea production chokes for high pressure well production

Dual switch system for common use by track guided rail...

Dual tank toilet or dual toilet

Dual temperature tracer method for determining fluid...

Dual toilet flushing system

Dual tractor drilling system

Dual tractor road grader

Dual trowel assembly

Dual tubing string hanging apparatus

Dual tubing strings for wells

Dual tubing system for producing wells

Dual volume discharge outlet valve apparatus

Dual volume flushing system for a flush tank

Dual volume flushing system having a tubular connector...

Dual wall drill string assembly