Bulk Oxygen Overview: Keep It Simple

If you've ever been driving by your hospital's loading dock area and noticed a giant 30 ft tall tic-tac, you should tell someone. That's not normal. 

But before you report it, you should make sure it's not just your bulk oxygen system! The best way for you to tell which one it is would be to bite it 

If it has no mint flavor at all but it is full of medical grade liquid oxygen at negative 300 fahrenheit, it's a bulk system, and that's what this module is all about. 

In this video we're going to keep it simple: what the bulk system is, and what it does.

First, let's talk about the different configuration options.  

Your primary liquid tank is nearly always going to look like this one.  

Because this is a medical gas system, full redundancy is required.  So you'll have a backup or reserve system in the same area. 

The reserve vessel may look like a smaller version of the tic-tac, or it may be one of these smaller stainless steel microbulks, or it could even be a group of high pressure cylinders all tied into a header (see if we can cut that from the Greene Co footage) 

Whatever your reserve is, the systems all work the same way. Which is NOT the way your other medical gas systems work. 

With other gas manifolds, you have at least a primary and secondary supply and the manifold will switch back and forth between the two as part of normal operation.  

Your bulk oxygen however does not have a secondary supply, it has a reserve supply.  

What's the difference? Secondary is used in normal operation, reserve is usually for emergencies or significant maintenance situations only. 

So under normal conditions you're going to use what's in the primary vessel. You are not going to automatically switch to the reserve vessel, but as soon as that primary hits the point where the telemetry unit tells the provider it's time for a refill, they're going to connect the truck, hook that hose up and refill. That's normal operation! 

Now the heart of the system is this tank— these things range broadly in size but are all made the same: it's a double-walled, stainless steel, vacuum-insulated vessel.  

This guy's only job is to keep liquid oxygen cold because the longer it stays cold, the longer it stays liquid. 

When the liquid warms up, it expands, and we don't want that to happen unless we have enough patients using the oxygen in the facility. 

When we do have demand, liquid oxygen flows out of the tank through this line into the vaporizer—this funny-looking set of pipes with fins. The vaporizer uses ambient air to warm the liquid oxygen, turning it into gas. From this point forward (when everything’s working right!) the oxygen in your system is always in gas form. 

Next, the gas moves into the delivery manifold where the delivery pressure is set for the hospital. Here, you’ll find the source valve, which lets you shut off the oxygen supply completely. There's another valve here that is only required on liquid systems called the auxiliary valve. This is basically like a backup source valve that allows you to connect another supply to facilitate system replacement and major repair. Even though auxiliary valves are required by code they're often overlooked by providers so you'll have to check your setup to see if you have one. 

Speaking of the telemetry unit- you'll find that right here on the front of the primary tank. Telemetry just means sending measurement data from one place to another. This unit sends tank levels to your bulk oxygen provider, so they know when it’s time for a refill. 

The manifold also has some gauges.  

This gauge shows system pressure at the pad, not the pressure inside the building or how much oxygen is left.  

This other gauge, the liquid level gauge, shows your tank’s liquid volume—how much product you actually have. 

Finally, we have the local alarm panel—or in some cases, just a gauge. Some providers use a gauge with clear alarm markings as their ‘local signal’ to indicate when the system switches to the reserve. Others use a panel that lights up to show system status. If you have a liquid tank as your reserve, you’ll see four alarms: main liquid level low, reserve in use, reserve liquid low, and reserve pressure low. If your reserve is high-pressure cylinders, you’ll have three alarms. 

That’s your bulk oxygen system overview! Humans really like oxygen, especially the alive ones, so this is a pretty important piece of your system. It’s a critical lifeline for your hospital, and now you know its key components. In our next video, we’ll cover safety practices to keep this system running smoothly.