Severn’s patented OCT TOV butterfly valve technology advances traditional triple offset valve (TOV) sealing technology even further, maximising sealing performance for critical flow control applications and high‑integrity isolation valves.
The Oblique Cone Technology (OCT) moves away from the traditional elliptical sealing shape and introduces a circular sealing geometry, enabling proven double offset butterfly valve sealing principles to be applied within the Severn OCT TOV Butterfly Valve design. This makes it ideally suited for high‑performance butterfly valves, severe service valve applications, and demanding process control environments.
In addition, trims traditionally associated with double offset butterfly valves — such as anti‑cavitation trims for control valves — can be incorporated into the TOV butterfly valve design. This versatility positions Severn’s OCT TOV Butterfly Valve as an ideal solution for combined isolation and control valve applications, where process stability, accurate flow regulation, and reliable shut‑off performance are essential.
Hybrid Sealing Technology – Advancing Butterfly Valve Performance
Severn’s significant investment in control valve research and development has been instrumental in introducing hybrid sealing technology into the OCT TOV butterfly valve.
By combining a hybrid polymer‑metallic valve seal, Severn applies the self‑compensating sealing benefits of triple offset valve technology to a polymer sealing system. The addition of a metallic sealing element ensures that if the soft seal becomes damaged during operation, the metal seal automatically engages, continuing to provide a reliable zero‑leakage butterfly valve seal.
This fault‑tolerant butterfly valve sealing system makes the OCT TOV butterfly valve particularly suitable for:
- Challenging and variable process conditions
- Severe service valve applications
- High‑cycle control valve duties
Proven Testing and Validation
The hybrid butterfly valve sealing system has undergone an extensive and rigorous testing programme, including:
- High‑cycle endurance testing
- Fire‑safe valve testing
- Extreme operating condition validation
These tests confirm that even in harsh operating environments, the OCT TOV Butterfly Valve delivers a high‑integrity sealing solution.
This level of performance would not be achievable with a conventional double offset butterfly valve, where seal damage typically necessitates seal replacement, resulting in unplanned plant downtime, increased maintenance intervention, and potential production losses.
Self‑Compensating Design and Reduced Wear
Severn’s OCT TOV Butterfly Valve is fully self‑compensating for wear, ensuring consistent sealing performance throughout the valve lifecycle.
The third‑offset camming action significantly reduces seal wear by minimising seal contact. Disc‑to‑seal contact occurs only during the final 1–2 degrees of valve closure, substantially lowering operating torque, friction, and mechanical wear.
In comparison, a standard double offset butterfly valve typically maintains seal contact over approximately 10 degrees of rotation, leading to increased wear and reduced long‑term reliability.
Built‑In Safety and Compliance
The standard OCT TOV Butterfly Valve design incorporates the requirements of the most stringent international valve standards.
Key safety features include a dual anti‑blow‑out shaft design, supplied as standard, ensuring the valve shaft cannot be ejected during operation — enhancing plant safety, asset protection, and operational integrity.
The hybrid polymer valve seal is fully compliant with EN ISO 90079‑36 (ATEX) requirements, making the valve suitable for hazardous area installations and ATEX‑rated process applications.
In‑Field Serviceability and Future‑Proof Design
Severn recognises that operating conditions can evolve beyond original design assumptions. To address this, the OCT TOV butterfly valve sealing system has been engineered with interchangeable seal options.
Where required, the hybrid seal can be replaced in‑field with a laminated seal or a solid metal seal — without replacing the main valve body or major components.
This ensures the OCT TOV Butterfly Valve remains:
- Fully serviceable in the field
- Upgradeable to suit harsher process conditions
- Optimised for safe operation, improved plant reliability, and reduced maintenance downtime
Find out more about Severn’s OCT TOV Butterfly Valve, advanced butterfly valve sealing solutions, and high‑performance isolation and control valves by visiting our website via the link below.
