Machining seal-ring grooves is part of the hectic production schedules in manufacturing of components for oil and gas production. With high functional security norms, American Petroleum Institute (API) grooves are made in Inco cladding, stainless steel, steel and even solid Inco alloys to precise tolerances and surface finish.
The scope for improving the manufacture of seal-ring
grooves was recognized by Stefan Persson, component manager within the
Sandvik Coromant energy industry segment, and his team. Component
feature machining is a speciality within this segment. Metalworking
World asked Persson about what has been achieved.
What is so special about American Petroleum Institute (API) groove machining that warrants this attention?
components in this sector are made with expensive materials and have
already incurred high manufacturing costs by the time one or several
grooves must be made. Mistakes can result in costly consequences,
security demands are high, and productivity is essential. Reliable,
stable machining that provides a smooth, flexible and efficient process
is the objective for manufacturers involved with this component feature.
But a satisfactory general solution to achieve this has not been
available, so there was huge potential for improvement.
to the production pressures, there are considerable metalcutting
challenges in making API grooves, including machinability of component
materials, chip control, consistency and reliability in fulfilling
quality demands and often the location of grooves on the component as
regards accessibility and tool overhang.
Early on we saw that the application requires a dedicated
solution to be successful and to be considerably better in all ways than
So what is this new solution for API groove machining: SpiroGrooving?
all, it is a patented innovation in machining methods – a simple yet
sophisticated manufacturing process. Clever use is made of a dedicated
cutting tool rather than using brute force. The process utilizes the
capability of modern CNC machinery and control. The program, with the
relevant values for an application, is generated using a proprietary
calculator/generator with a user-friendly interface. A post processor is
the brain behind the process related to the machine tool.
Tooling is based on state-of-the-art, proven standard concepts,
where modularity provides broad groove application flexibility. This is a
new type of indexable insert tool, based on proven concepts in an
innovative way, performing very efficient, light-cutting circular
ramping simultaneously on the outside and inside diameter of the groove.
Conventional methods require a new set of tools for every groove type
or size, but one SpiroGrooving tool covers a range of diameters,
providing flexibility in production and a minimized tool inventory.