Hospitals that rely on a bulk liquid oxygen system need a way to keep oxygen flowing if the bulk supply is interrupted, whether from a delivery problem, equipment failure or damage to the supply line. That’s the job of the emergency oxygen supply connection (EOSC). This guide explains what an EOSC is, when it’s required and how to keep it ready.
What is an emergency oxygen supply connection?
An EOSC is a dedicated, exterior inlet connected to the facility’s oxygen main line. If the bulk system can’t supply oxygen, a gas supplier can bring a temporary source (typically a liquid oxygen trailer or truck) and connect it at the EOSC to feed the building’s pipeline directly, bypassing the bulk tank.
When is an EOSC required?
Under NFPA 99, an EOSC is generally required when the bulk oxygen supply system is located outside the building it serves, so a temporary supply can be connected if the main source fails. Requirements and exceptions depend on the code edition your authority having jurisdiction has adopted and your system design, so confirm with your engineer and AHJ.
Main components of an EOSC
- Exterior inlet in a lockable enclosure, accessible to supply vehicles and labeled “Emergency Low Pressure Gaseous Oxygen Inlet” (or as required)
- Isolation valve so the inlet can be opened or closed
- Check valves in both the main line and the EOSC line so oxygen can’t flow backward into the bulk system or out of the inlet
- Pressure relief valve to protect the pipeline
- Connection to the main line downstream of the bulk system’s main shutoff valve
See our emergency oxygen supply connection product.
Where to locate the EOSC
- On the building exterior, where a supply truck can park and reach it
- Protected from vehicle damage and tampering
- Away from parking areas or places where oil and grease could contaminate the connection
- Clearly labeled and shown on facility drawings
Keeping the EOSC ready
- Inspect the enclosure, labeling, cap and valves during routine medical gas inspections
- Confirm check valves and relief valves are in place and working
- Keep the access path clear for delivery vehicles
- Document how to use the EOSC in your emergency operations plan, and confirm your gas supplier can provide a temporary source on short notice
- Coordinate any modifications with testing and verification
EOSC vs. reserve supply: what’s the difference?
A bulk oxygen system also has a reserve supply (cylinders or a secondary tank) that switches in automatically when the primary supply runs low. The reserve is part of the bulk system. The EOSC is a separate inlet for when the entire bulk system, reserve included, can’t deliver oxygen.
FAQs
Does every hospital need an EOSC?
EOSCs are typically required for bulk oxygen systems located outside the building. Facilities supplied entirely by cylinder manifolds usually don’t need one. Check your code edition and AHJ requirements.
Who connects the temporary oxygen supply?
Your oxygen supplier usually brings and connects the temporary source, coordinating with facilities staff.
How often should the EOSC be inspected?
Include it in your routine medical gas inspection and maintenance program, at least annually or as your risk assessment requires.
Need an EOSC installed, replaced or inspected in Southern California? Call Medical Gas Resources at 714-897-7530.
