New valve targets suction‑side risks in oil‑free HVAC
Danfoss has introduced the OFB range, a newly developed tight oil‑free shut‑off ball valve designed for chillers and heat pumps equipped with Turbocor® compressors, marking the latest addition to its EXO – Extended Oil‑Free program. Installed on the suction side, the OFB is intended to work both as a service valve and—when motorised—as an anti‑refrigerant liquid migration valve, addressing a long‑standing vulnerability in high‑performance, oil‑free systems.
Oil‑free architectures depend on precise inlet conditions and strict control of refrigerant behaviour during standstill and start‑up, particularly in mission‑critical environments such as data centres and advanced HVAC installations. Uncontrolled liquid migration can threaten compressor protection and uptime; the OFB aims to manage these risks while avoiding the pressure losses often associated with additional components in the suction line.
Three‑in‑one design: cone, isolation and motorisation
At the core of the product is a three‑in‑one functional design that integrates a smooth suction‑cone transition, a tight shut‑off isolation ball valve and full motorisation capability in a single housing.
- The suction cone is engineered to deliver excellent inlet flow quality with negligible pressure drop, helping maintain stable compressor operation and preserve system efficiency.
- The tight ball valve provides positive isolation, enabling safe service and maintenance without compromising the oil‑free circuit.
- When fitted with an actuator, the valve becomes an active anti‑migration device, closing during shutdown and start‑up phases to prevent refrigerant from moving into vulnerable sections of the system.
By consolidating these functions, Danfoss positions the OFB as a way to simplify piping layouts and reduce the number of individual components and joints on the suction side areas that are both performance‑sensitive and difficult to access in dense machine rooms.
Modular compatibility with all Turbocor® TGx and TTx models
The OFB series has been developed as a fully modular solution compatible with all Danfoss Turbocor® TGx and TTx compressors, covering both new OEM designs and retrofit projects. A total of 12 inlet flange options in 3″, 4″ and 5″ sizes allow the valve to match a wide range of compressor connections, while supporting multiple global standards including ANSI, ASTM, DIN and EN.
The mechanical design is rated for operating temperatures from –40 °C to +100 °C, enabling deployment across diverse climates and applications, from comfort cooling to process and data‑centre environments. As part of Danfoss’s broader EXO portfolio, the OFB sits alongside components such as the OFC check‑and‑stop valve and the recently introduced PTS staging valves, which collectively target higher reliability and efficiency in oil‑free systems.
Fast, durable actuation for mission‑critical duty
To complete the assembly, Danfoss offers the OFB with compact MQT electrical actuators that use brushless motor technology and deliver a 10‑second response time, enabling rapid isolation or migration control when operating sequences demand it. Thanks to the valve’s low breakaway torque, these actuators can remain small and energy‑efficient while applying minimal mechanical stress to the stem and body.
Mechanical robustness is further supported by a reinforced stem sealing system with strong guide bearings and top‑mounted support, designed to prevent misalignment and limit wear under continuous operation and frequent cycling. Danfoss says the complete valve–actuator combination has been endurance‑tested to 100,000 cycles, reflecting the demands of data‑centre and large‑HVAC duty where components are expected to operate flawlessly over long service lives.
Raising the bar for oil‑free chiller reliability
With oil‑free Turbocor® technology now widely adopted in premium chillers and heat pumps, particularly in sectors where uptime and efficiency are non‑negotiable, the OFB is intended to tighten control over a critical interface point in the refrigerant circuit. By combining optimised flow, tight isolation and smart actuation in one modular unit, Danfoss aims to reduce both engineering complexity for OEMs and operational risk for end users.
Industry coverage has framed the launch as another step in Danfoss’s strategy to turn oil‑free compressor systems into a fully integrated ecosystem of matched components—extending beyond the compressor itself to valves, staging devices and control architectures that are designed from the outset to work together. For operators of data centres, hospitals, airports and large commercial buildings, the OFB’s arrival signals that suction‑side reliability is moving from a design afterthought to a front‑line feature in the next generation of high‑efficiency HVAC equipment.