Chapter 4: From Deep Sea to High Vacuum – Adapting Subsea PTZ Camera Technology for Extreme Vacuum Environments
Chapter 4: From Deep Sea to High Vacuum – Adapting Subsea PTZ Camera Technology for Extreme Vacuum Environments
At YingDiGe (Hangzhou) Technology Co., Ltd., we have spent over a decade mastering reliable solutions for extreme underwater environments – deep‑sea high pressure, seawater corrosion, and subsea electrical interconnection. Our pressure vessels, watertight connectors, and underwater cameras are proven in ROVs, offshore wind, and scientific drilling.
Recently, a new challenge emerged: high‑vacuum (HV) PTZ cameras.
The customer requirements were clear but demanding:
· Operate in high vacuum (pressure below 10⁻⁴ Pa, no air cooling)
· No outgassing that could contaminate the vacuum chamber
· Fit through a 100 mm inner‑diameter pipe (camera body < 70 mm diameter)
· Metal housing, minimal plastics or grease
At first glance, deep‑sea and high‑vacuum environments seem opposite: one resists external crushing pressure, the other prevents internal leakage into vacuum. However, the enabling technologies – sealed pressure housings, feedthroughs, and thermal management – share strong foundations. This chapter explains how we adapted our subsea expertise to build a vacuum‑compatible PTZ camera.
1. Why Not Just Use an “Off‑the‑Shelf” Vacuum Camera?
True vacuum‑compatible PTZ cameras are rare, especially with a < 70 mm diameter. Most industrial PTZ cameras contain plastics, standard lubricants, and sealed motors that outgas in vacuum. Motion systems can cold‑weld or seize without proper lubrication. Electronics overheat because convection is absent.
We therefore chose a hermetic pressure‑vessel approach – a concept very familiar from our subsea work, but with key differences.
2. The Core Adaptation: From Underwater Pressure Housing to Vacuum Enclosure
Requirement Underwater (our heritage) High‑Vacuum (new adaptation)
Pressure direction External high pressure Internal 1 atm, external vacuum
Sealing Rubber O‑rings (compressed outward) Metal C‑seals or baked‑out FKM
Outgassing Not critical (water immersion) Extremely critical
Feedthrough Watertight connector (external pressure) Vacuum feedthrough (internal pressure to vacuum)
Heat dissipation To surrounding water Conduction + radiation only
Design decision: A 316L stainless steel cylindrical housing with diameter 68 mm – safely passing through a 100 mm pipe while leaving clearance for cables and mounting.
Key change: The housing is now evacuated outside, keeping internal air at 1 atm dry nitrogen. This means the PTZ camera and pan‑tilt unit inside see normal air convection, lubrication, and cooling – no special vacuum motor or grease is required for the moving parts.
3. Sealing for Vacuum vs. Underwater
Our standard underwater O‑rings (Viton®, EPDM) are excellent for high pressure, but in high vacuum they continuously outgas – water vapor, plasticizers, and volatile compounds. That is unacceptable.
We replaced them with:
· Metal C‑seals (Helicoflex type) for static vacuum interfaces
· Baked Viton® (pre‑degassed at 200 °C for 24 h) for less critical dynamic seals, with careful outgassing verification
The optical window uses a fused silica or sapphire window compressed against a metal gasket – no epoxy, no elastomer inside the vacuum side.
4. Cable Feedthrough: From Watertight to Vacuum‑Tight
We already manufacture high‑reliability underwater connectors. For vacuum, the requirement flips:
· The vacuum side is inside the connector body.
· The air side is outside.
Our solution: Ceramic‑pin, all‑metal vacuum feedthroughs (Kovar or stainless steel flange, Al₂O₃ insulation). They are baked at 400 °C during manufacturing to remove adsorbed gas, achieving helium leak rates below 1×10⁻⁹ Pa·m³/s – fully compatible with UHV (Ultra‑High Vacuum).
For cable harnesses, we removed standard PVC or rubber jackets inside the vacuum chamber and used PTFE‑ or PFA‑insulated wires, which have low outgassing.
5. Thermal Management – No Air, No Problem
Without convection, heat removal relies solely on conduction to the housing and radiation to surrounding walls.
We mounted the main heat sources (image sensor, processor, motor drivers) directly onto thermal pads or a copper spreader that contacts the stainless steel wall.
Additionally, we implemented a mechanical pan‑tilt brake so that the motors can be fully powered down when not moving – greatly reducing heat load.
6. Motion System: No Vacuum‑Special Motors Needed
Because the PTZ mechanism stays in internal air at 1 atm, we used a standard industrial mini PTZ module. Only the housing, feedthrough, and window face vacuum.
This is the key economic and technical advantage of the pressure‑vessel approach – we avoid expensive vacuum‑rated stepper motors and special greases.
For the rare case where a motor must be in vacuum (e.g., very small diameter with no room for a housing), we can retrofit with NyeTorr® 6300 vacuum grease, but that was not required for this 68 mm design.
7. Verification & Testing
We performed three critical tests before delivery:
Test Method Result
Leak rate Helium mass spectrometer < 1×10⁻⁹ Pa·m³/s (vacuum side)
Outgassing RGA (residual gas analyzer) after 24 h pumping Water vapor dominated; no hydrocarbons above 1×10⁻⁸ Pa
Thermal 8 h continuous PTZ motion in vacuum chamber (10⁻⁴ Pa) Housing temperature stabilized at 48 °C; no overheating
The camera passed all customer acceptance criteria.
8. Conclusion & Available Services
This project proved that subsea pressure‑housing technology can be successfully migrated to high‑vacuum applications – with careful modifications in sealing, feedthroughs, and materials.
At YingDiGe, we now offer:
· Custom vacuum‑compatible PTZ cameras (diameters from 50 mm to 150 mm)
· Vacuum feedthroughs (based on our watertight connector platform)
· Low‑outgassing cable harnesses for vacuum chambers
· Consulting on adapting underwater designs for space, accelerator, or thin‑film deposition environments
If your project requires a reliable, cost‑effective vacuum camera solution that fits through a small pipe and keeps your chamber clean – contact us. Our deep‑sea heritage gives you vacuum confidence.
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YingDiGe (Hangzhou) Technology Co., Ltd.