Selection and preparation for automation
Record process conditions (medium—lubricated or dry—, pressure and temperature) and determine the required operating torque (break/run/seat) with margin. Choose the ISO 5211 size and stem square so that future actuators and worm gears fit without modification. For electric or pneumatic automation we take into account the available power supply or compressed air, desired travel time, fail-safe behavior and feedback signals. Prefer manual operation for now? Then we fit a lever or worm gear that can later be easily replaced or combined with an actuator.
Why a bare-shaft ball valve?
- Flexible & future-proof: automate later without replacing the valve; lower total cost.
- Fast retrofitting: ISO 5211 top and correct stem interface make installing an actuator or worm gear easy.
- Material to suit: steel, brass or stainless steel with seats according to your medium and temperature.
Valve Automation Center
Ebora provides adapters, assembly and testing in the Valve Automation Center. You receive test reports and documentation on request; we supply the set fully assembled and validated.
Options: manual operation, worm gear and automation
- Manual: compact lever for simple open/close functions and low investment cost.
- Worm gear: increases ease of operation at high torques; suitable for position locking and fine metering.
- Automate: choose later for pneumatic (fast, fail-safe) or electric (modulating, bus).
Valve Automation Center
Ebora provides adapters, assembly and testing in the Valve Automation Center. You receive test reports and documentation on request; we supply the set fully assembled and validated.
Advice or quote
Send your process data (medium, pressure, temperature, desired connection, ISO 5211 size and required options). We size the free-stem valve and prepare it for your future automation.
Contact us for advice or a quote.
Frequently asked questions about free-stem ball valves
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. This makes the valve flexible and cost-efficient in changing installations.
How do I prepare a bare-shaft valve for later automation?
Start with the required torque (break/run/seat) under your process conditions and choose the correct ISO 5211 flange size and stem square. Check that there is sufficient space for an actuator or worm gear and that the allowable load on the piping remains within the standard. Determine whether you need on/off or modulation and which fail-safe behavior fits. This avoids rework or replacement when you automate later.
When should I choose a worm gear instead of a lever?
A worm gear is ideal for higher torques, larger diameters or limited installation space where a long lever is impractical. It offers finer metering and can be supplied with locking. The gear reduction lowers operating force and improves ergonomics and safety. Later an actuator can be mounted on the same ISO 5211 top.
Can I automate later without modifying the piping?
In most cases yes, provided the valve has the correct ISO 5211 topworks and stem profile and there is space for an adapter or bracket. Connection dimensions (DIN/ANSI, threaded/welded/flanged) remain unchanged because the valve stays in line. We mount the actuator, switches and optionally a worm gear on the existing valve.
Which materials and seats are suitable?
Generally applicable are steel, brass and stainless steel, depending on medium and environment. We select seats for chemical resistance, temperature and wear; PTFE variants are widely used. With abrasive or dry media we calculate extra torque and choose wear-resistant seats. This keeps the shut-off class within specification over the service life.
What if the required operating torque turns out higher later?
Preferably choose now an ISO 5211 size and stem profile that also allow a heavier actuator. We calculate with torque margin and take into account medium changes, pressure fluctuations and temperature peaks. If necessary we provide an adapter/bracket or switch to a worm gear for manual operation. Our Valve Automation Center can perform the upgrade quickly and in a controlled manner.
