CONSERVE HELIUM
An Essential Resource for All Generations
OCEAN SCIENCE · HUMAN WORK · CONSERVATION
Recovering Helium from Diving
From a diver’s helmet to the support vessel, gas recovery can retain helium that would otherwise be discharged.
Capture and process
Retain gas from divers, bells and chambers.
Verify before reuse
Gas quality remains a life-support requirement.
Preserve helium’s service to humanity.
Applications / Deep diving / Recovery
On this page · Recovery routes · Salvage case study · Gas processing · Gas quality · Measurement · Sources
Three ways to keep gas in service
- Diver rebreather: recirculates breathing gas through equipment carried by the diver. Carbon dioxide is removed and oxygen replenished.
- Helmet reclaim: returns exhaled gas to surface equipment through a dedicated hose in the diver’s umbilical.
- Chamber and bell recovery: collects gas released during selected lock and depressurization operations, then processes it for storage and reuse.
These systems address different gas streams. A recovery figure for one component should not be presented as the efficiency of the entire diving operation.
Sources: NOAA Ocean Exploration [S92] · JFD Limited [S94] · JFD Limited [S95]
A salvage project that advanced reclaim
JFD’s historical account describes gas reclaim during the 1981 salvage of gold from HMS Edinburgh, at a reported depth of 256 meters. Modified diving helmets routed exhaled gas back through the umbilical rather than exhausting it into the sea.
The company describes a system using a gas booster, water traps and carbon-dioxide scrubbing to recover and store more than 90% of the diver’s exhaled gas. This is a manufacturer’s retrospective account of that operation. It is not an independently established recovery percentage for all present-day diving systems.
The case illustrates the value of making recovery part of the original operating design: retained gas can reduce the new helium that must be delivered to an offshore operation.
Sources: JFD Limited [S94]
Collect, purify, compress and verify
JFD’s Helipure technical sheet describes a chamber-gas recovery arrangement in which gas from equipment locks and bell depressurization enters a collection bag. Compression and filtration move it into storage.
Air entering the recovered gas can introduce nitrogen and oxygen that must be accounted for. The manufacturer describes membrane separation to reduce unwanted gases, followed by storage and analysis before reuse.
This is compressed-gas recovery. Liquefaction is not a required step in the documented process. It differs from a laboratory system that returns recovered helium to a liquid bath.
The technical sheet’s sample separator performance describes a particular operating example, rather than a guaranteed total-system recovery rate.
Sources: JFD Limited [S95]
Recovery is part of life support
Recovered gas must meet the requirements of its next use. Filtration, carbon-dioxide removal, composition analysis, equipment maintenance and monitoring all matter. Gas that has been collected is not automatically ready to breathe.
IMCA documented a saturation-diving near miss involving suspected elevated carbon dioxide in reclaimed breathing gas. The incident illustrates why gas quality and equipment condition must be verified throughout the recovery process.
Conservation must support reliable life support. This page describes the purpose of recovery equipment; it does not provide instructions for constructing, adjusting or operating a breathing-gas system.
Sources: JFD Limited [S95] · International Marine Contractors Association [S96]
What should operators measure?
Conserve Helium proposes tracking the whole operation alongside the performance of individual recovery components:
- Initial helium inventory and subsequent helium purchases.
- Gas collected from divers separately from gas collected from chambers and bells.
- Helium recovered and approved for reuse, distinguished from total mixed-gas volume.
- Losses through leakage, deliberate discharge, processing and transfers.
- Inventory remaining at the end of the assignment, including gas carried forward for future work.
Volumes should state their reference temperature and pressure. Results should identify the period measured and the operating activity, such as diver-hours. This makes initial inventory, circulating gas and new helium demand easier to distinguish.
These are proposed reporting criteria. The reviewed sources do not establish a comparable, independently verified recovery rate across the industry.
Sources and next steps
[S94] JFD Limited — HMS Edinburgh: The Origins of Gas Reclaim in Commercial Diving
[S95] JFD Limited — Helipure Membrane Gas Separation System
[S96] International Marine Contractors Association — Near-miss: Suspected high levels of CO2 in diver breathing gas
The JFD documents provide technical and historical evidence from an equipment manufacturer. The IMCA report supplies an operational safety example. Equipment availability and specifications should be confirmed with current documentation.
