The PVDF press fittings for gas differ in only one significant technical aspect compared to press fittings for sanitary and heating applications. The fittings have a special O-ring that is made from the HNBR and is resistant to gas. To make this difference visible, every pressure sleeve has a yellow band. The fittings for gas should never be used for sanitary applications or heating applications. Similarly, fittings for gas should only be used in combination with the yellow HENCO multilayer pipe for gas. The Henco system for gas is only permitted in countries where a gas quality mark has been granted.PVDF offers the user a unique combination of properties:Highly resistant to pressure and temperatureExcellent mechanical strengthExtreme flexibility: bending up to 10° is possiblePerfectly suited for drinking water and foodHighly resistant to chemicals and corrosionEmbedding is possible without extra protection