Pressure Compensated and Seawater Resistant Fiber Optic Rotary Joints

In a government-funded project, SPINNER developed special-purpose fiber-optic rotary joints (FORJ) for deep sea applications and had them patented.

Two differfent types are available:

• 1.17pc*: single channel FORJ with an external diameter of 17 mm

• x.65pc*: 2 to 8 channel FORJ with an external diameter of 65 mm

*pc = pressure-compensated

To offset enormous deep-sea pressures, these rotary joints are filled with fluid and equipped with a special pressure compensation mechanism developed and tested by SPINNER. They are able to compensate for pressure differentials between zero and approximately 1000 bars. The tried-and-proven adaptable internal structure of the type 1.14 single-channel rotary joint is also used in them, thus minimizing insertion losses while rotating through 360° (insertion loss rotational effect or WOW). High return flow attenuation is also achieved, thus eliminating the need for any additional components.

Type 1.17pc - for deep sea down to 10,000 meters

The single-channel fiber-optic rotary joint FORJ 1.17pc from SPINNER was developed with a pressure compensation system for deep sea applications down to depths of up to 10,000 m. Due to the materials used, this rotary joint is saltwater-resistant and also features a rotating contact seal. To minimize insertion losses, special optics are used.

Applications

Deep-sea - ROVs (Remotely Operated Vehicle) - renewable Energy

Specifications

• Channel count: 1
• Fiber types: single-mode (SM), multi-mode (MM)
• Max. insertion loss: 1.5 dB (SM), 2.5 dB (MM)
• Insertion loass variation over rotation max: 1.0 dB
• Return loss: 50 dB (SM), 35 dB (MM)
• Wavelength: 1310 nm/1550 nm (SM), 850 nm/1300 nm (MM)
• Rotational speed: 60 rpm
• Weight (excl. connectors): 60 g
• Torque: 0.3 Nm
• Degree of protection: IP68* up to 4,500 m operational depth, up to 7,500 m on request
• Recommended temperature range: -40 °C to +85 °C

Type x.65pc - pressure compensated - with 2 to 8 channels

Like the 1.17pc, the x.65pc with an outer diameter of 65 mm has also been equipped with the patented pressure compensation system. As a result, no additional pressure compensation system is required. The rotary joint is equipped with the same rotating contact seal and can connect between two and eight channels between the rotor and stator. The typical insertion losses range between one and two dB independently of the number of channels. For the x.65pc, an FC or ST coupler version is available to facilitate installation in customer systems.

Applications

Deep-sea - ROVs - tether management systems (TMS) - civil and defence underwater applications

Specifications

• Channel count: 2 - 8
• Fiber types: single-mode (SM) E9/125
• Max. insertion loss: 2 - 4 CH: 3.5 dB (typ. 1.5 dB), 5 - 8 CH: 4.5 dB (typ. 2.5 dB)
• Insertion loass variation over rotation max: 1.5 dB (typ. 0.75 dB)
• Return loss: 40 dB (typ. 45 dB)
• Wavelength: 1310 nm/1550 nm
• Rotational speed: 60 rpm
• Weight (excl. connectors): 3,000 g
• Torque: 1 Nm
• Degree of protection: IP68 up to 4,500 m op. depth - up to 10,000 m on request, seawater resistant
• Recommended temperature range: -10 °C to +75 °C

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