Image via Chemtech
Medical oxygen valves and other gas valves feature a complex and refined construction that makes them suitable for a range of applications. This means valves typically have a number of different components, each precisely engineered to achieve a specific purpose within the gas system.
Learn more about the different features of these gas valves and gain the understanding you need to select the right valve for your specific application.
Components and Features of Oxygen Gas Valves
Operating Mechanism
Medical oxygen valves are fitted with mechanisms that enable the opening and closing of the valve via the application of torque or turning force. In many instances, this mechanism will be a handwheel, which will be ergonomically designed to fit the typical human hand size for easy operation. Different valves will be rated for different levels of torque. However, it is unlikely that human operators will apply dangerous levels of torque to the valve if they are operating the device by hand.
It is not recommended to use any mechanical aids to assist with opening. If the valve is too tight to open by hand, this might be an indication of damage. Over-torquing can exacerbate this problem or even cause the valve to break down altogether.
Another operating mechanism you may encounter on your valve is the spindle key. Again, you should be able to open and close the valve by hand using the spindle key. Do not use any lever extender to assist with opening, as this could result in harmful levels of torque applied to the valve. Check the specifications of the valve model if you are unsure about safe levels of torquing.
Regulators
In a gas valve, a regulator is a component fitted within the valve itself to regulate the pressure levels between the input and output stream. Pressure levels inside oxygen gas cylinders can vary greatly. These levels will typically be between 25 and 100 PSI for medical oxygen cylinders but may be higher or lower than this for other types of cylinders or from wall delivery outlets. It is the regulator that translates this pressure to a level that can be handled by the valve.
Many medical oxygen valves will have regulators already integrated into the design. However, some types of valves will have detachable regulators that need to be fitted prior to operation. Running the oxygen gas valve at a pressure outside of its rated parameters can be dangerous, so it is important to ensure that regulators are fitted and in full working order before operation.
Pressure Relief Devices
Pressure Relief Devices, or PRDs, operate in a similar way to regulators but are fundamentally different. While a regulator is designed to work continuously, managing the pressure of the oxygen gas passing through the valve, PRDs are designed as safety measures, releasing pressure within the valve when levels grow too high.
When the pressure reaches a certain level, the valve will open to allow gas to be released into a reservoir, reducing wear and tear on the system. The idea of these devices is to ensure that sensitive components within the valve — or elsewhere in the system — continue to perform well across their whole lifecycle. PRDs are not fitted internally to the valve itself but can be placed in sequence with the valve to prevent damage. Make sure that the PRD is tuned to be compatible with the pressure rating of the valve you are using.
Seals
Seals are often constructed of rubber or polymer and fit within the construction of the valve itself. They are intended to prevent gases from escaping from the system prematurely or unpredictably. They also reduce friction on the turning mechanism so that it can be opened or closed with ease, without the need to use a lever extender or other mechanical aid.
One of the key benefits of these types of seals is that they enable the valve to continue operating effectively even when torque is at an extremely low level. For instance, if an operator needs to quickly shut off the flow of medical gas through the valve, they only need to apply a small amount of turning force to the handwheel or spindle key. The pressure applied to the seal will prevent the flow of gas without the need for over-torquing. The valve can then be reopened easily and reliably when required.
Shroud
The shroud fits over the top of the valve and allows for easy portability and compatibility with existing oxygen cylinders and systems. Shrouds come in many different sizes and configurations, but all should be designed to make operation simple and effective for your teams when they utilize the oxygen gas valve.
Typically, shrouds are constructed using polymer blends to provide a sturdy and robust component for the valve. The construction material should resist chemical and ultra-violet light degradation, extending the lifespan of the component.
Construction
Oxygen is a reactive gas, which means any valve components that come into contact with the gas itself need to resist this reactivity. Metals such as iron will form rust deposits when they come into contact with oxygen and will degrade over time until they become useless. This is why metals such as stainless steel or brass — which do not react with oxygen, even at high concentrations — are typically used in industrial or medical oxygen valve construction.
The valve should also be constructed in such a way as to avoid magnetic attraction. This makes the valve suitable for use in areas with strong magnetic forces, as are typical in many medical applications.
Read Up on the Specifications of Your Chosen Valve
The gas valve market is a diverse one, and different manufacturers provide a range of valves across a broad spectrum of specifications. Be sure to check out the specs of each valve you intend to use at your facility, clinic, or other place of business. This ensures that you are utilizing the valve for its intended purpose and are not placing dangerous levels of strain or wear and tear on its components.