What exactly is a bare-shaft ball valve?

A free-stem version is a ball valve without a mounted operator, prepared with an ISO 5211 top and matching stem interface. You can later mount a lever, worm gear or actuator without replacing the valve. The ball switches 90° between open and closed with low pressure drop in the open position.

How do I prepare a bare-shaft valve for later automation?

Determine the required torque and choose the correct ISO 5211 flange size and stem square. Check the installation space and the load on the piping. Determine whether you need on/off or modulation and which fail-safe behavior is required.

When should I choose a worm gear instead of a lever?

A worm gear is suitable for higher torques, larger diameters or limited space. It reduces operating force and allows finer metering. Later an actuator can be mounted on the same ISO 5211 top.

Can I automate later without modifying the piping?

Yes, provided the valve has the correct ISO 5211 topworks and stem profile and there is space for an adapter or bracket. The line connections remain unchanged; we mount the actuator and accessories on the existing valve and perform a function test.

Which materials and seats are suitable?

Steel, brass and stainless steel are common; the choice follows medium and environment. We select seats for chemistry, temperature and wear; PTFE variants are widely used. For dry or abrasive media we calculate extra torque.

What if the required torque turns out higher later?

Choose now an ISO 5211 size and stem profile that allow a heavier actuator. We calculate with margin and take medium, pressure and temperature into account. If necessary we apply an adapter or worm gear.

Ball valve with free shaft for later automation

Ball valve bare-shaft

A bare-shaft ball valve is supplied without an operator, allowing you to automate later (pneumatic or electric) or to fit a handwheel/worm gear. The valve is technically prepared with an ISO 5211 mounting pad and matching stem interface, so you don’t need to replace the valve if the control method changes. This keeps investment low and the installation flexible. We supply bodies in steel, brass and stainless steel and match the seats to medium, pressure and temperature for a long, tight-shutoff service life.

What is a Bare-shaft version?

The valve is delivered with a bare stem and topworks without a mounted lever or actuator. The ball rotates 90 degrees between open and closed; in the open position the bore aligns with the pipeline (low pressure drop), in the closed position the bore is perpendicular (tight shut-off within class). Thanks to the ISO 5211 mounting pad and the correct stem square/drive size, an actuator or manual operator can be fitted later, optionally via an adapter or bracket.

Design, interfaces and materials

Preparation for automation starts with the right topworks: ISO 5211 flange (F03 to F10, etc.) and a stem interface that matches the chosen drive principle. Accessories (switch box, end stops) are easily added once you automate. Ball valves are available in steel, brass, plastics and stainless steel; seats (e.g., PTFE variants) are selected for chemistry, wear and temperature. End connections include threaded, welded or flanged in DIN/ANSI — the choice follows your process and piping.