Demand valve

Demand valve

A demand valve, also known as a ventilation demand valve or oxygen demand valve, is a valve that allows the flow of gas – air or oxygen – only when a change in pressure occurs that indicates a demand. This means that the gas is only released when a demand is signaled by the pressure change in the patient’s inspiration or the filling of a ventilation bag after the expulsion phase. Just “ON DEMAND

Our product selection from the Kategorie: Demand valve

DEHAS demand valve QualityFLOW O2 MTV for the application of 100 vol.% O2 during manual ventilation with the resuscitator bag as well as during direct...
QualityFlow N2O for the application of the mixture of nitrous oxide and oxygen. The low inspiratory resistance results in high patient comfort. Operat...
QualityFlow N2O for the application of the mixture of nitrous oxide and oxygen. The low inspiratory resistance results in high patient comfort. Operat...

Demand valve: The functions & features

Using a membrane, the demand valve detects a negative pressure at the outlet to the patient (mask) or to the ventilation bag. The negative pressure (approx. 0.5 mbar) is created when the patient breathes in or the ventilation bag is sucked in. This triggers the demand valve to open and the patient is supplied with oxygen or air. If the negative pressure falls below the response threshold, the valve closes again (compression of the ventilation bag ends or the patient no longer breathes in).

A further advantage of using a demand valve during ventilation with a ventilation bag, in contrast to a reservoir bag supplied by constant flow, is that the patient can be supplied with 100% pure oxygen, which significantly increases the effectiveness of ventilation (oxygen supply and gas exchange). When using a reservoir bag, only a maximum O2 enrichment of up to 84% O2 is possible due to the additional intake of ambient air.

The main areas of application for demand valves are in the fields of anesthesia / pain therapy / dentistry / emergency services.

But our demand valves can do even more: in the demand valve version with manual ventilation function (QualityFLOW MTV), in addition to the normal function of supplying gas “on demand”, manual ventilation is also possible at the touch of a button without a resuscitation bag in the demand valve MTV version.

Demand valves are also suitable for the administration of nitrous oxide as required. With our QualityFLOW N2O, we offer a special version with integrated respiratory gas discharge (expiratory) for this purpose. This prevents enrichment of the ambient air with nitrous oxide.

In conjunction with our nitrous oxide/oxygen mixers from the QualityMix family, the valve can be used both with a directly connected mask and in conjunction with a breathing tube.

Frequently asked questions

A ventilation bag (Ruben bag), also known as a manual resuscitation bag or self-inflation bag, is a device used to manually ventilate patients who cannot breathe on their own. Here is a description of how an Ambu bag works:

  1. Structure: A ventilation bag consists of a squeezable bag, a connection for an oxygen source, a valve system and a face mask or endotracheal tube. The bag is often made of a flexible but robust material.
  2. Manual operation: The rescuer squeezes the bag to channel air (or oxygen) into the patient’s lungs. When the bag is released, it refills with air or the connected oxygen.
  3. Valve system: The valve system ensures that the air flows in one direction – from the bag into the patient’s lungs and not back. It also prevents exhaled air from getting back into the bag.
  4. Connection to the patient: The ventilation bag is connected to the patient either via a face mask, which fits over the patient’s mouth and nose, or via an endotracheal tube, which is inserted into the trachea.
  5. Controlled ventilation: The caregiver can control the frequency and volume of ventilation by squeezing the bag at an appropriate rhythm and adjusting the amount of pressure applied.
  6. Oxygen supply: Many ventilation bags allow the connection of an oxygen source to increase the oxygen content of the supplied air, which is particularly important in emergency situations.

Ventilation bags are an essential part of emergency equipment in hospitals, ambulances and for first responders. They enable effective and life-saving ventilation in situations where patients cannot breathe on their own.

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