Medical gas manifolds have been utilizing shuttle valves to change from the primary bank to the secondary bank for generations. The gas from both the primary bank and secondary bank are piped into each side of the shuttle valve. There is a shaft inside the valve that presses on a diaphragm as the shaft moves from one side to the other. When the pressure from the primary bank depletes, the secondary bank pushes the shaft and diaphragm to the other side due to its higher pressure, which allows the flow of gas from the secondary supply to inititate.
 

Although shuttle valves have been in use for so many years, they have not been too reliable. Normal wear on a shuttle valve ultimately always causes failure. Once the components wear, leaks occur and simultaneous feeding from both the primary and secondary banks may occur. If the latter occurs there could be a significant increase in the risk to patient safety.

 

If the shuttle valve allows the flow of gas from both banks simultaneously, there is the chance that both banks can deplete at the same time. Depending on the specific gas type and the level of the facility, if undetected this could put patients in immediate danger of mortality.

 

Another downside to medical gas manifolds that utilize the shuttle valve technology is maintenance. If the shuttle valves need any kind of maintenance (repair or replacement) it is necessary to completely shut down the flow of gas from both the primary and secondary supplies in order to do so.
 

More advanced technologies are being used by some medical gas manifold manufacturing companies which are proven to be superior to that of the shuttle valve. The manufacturers utilize two pressure switches (one on each of the two bank regulators) which sense when one bank is depleting and automatically switches over to the other bank. The system was designed with maintenance in mind and allows for continuous supply to the facility when changing a pressure switch, bank regulator or a final line regulator.

 

The shuttle valve, although it has been a mainstay in the medical gas manifold industry, is old technology that requires too much maintenance and puts patients in harm's way.

What technology does your manifold use?

 

 

By:

 

Jay D’Agostino

NITC/ASSE 6020 Medical Gas Inspector