APPARATUS AND DEVICES FOR FEEDING GASES AND LIQUID GASES INTO CONTAINERS, IN PARTICULAR CONTAINERS USED IN THE FOOD INDUSTRY, MAINLY CONSISTING OF A SUPPLY AND INJECTION UNIT; COMBINATIONS OF VALVES AND NOZZLES OR INJECTORS RESPECTIVELY, BEING PARTS OF GAS OR LIQUID GAS FEED APPARATUS; SWITCHING, PRESSURE REDUCING OR PRESSURE REGULATING VALVES, BEING PARTS OF GAS OR LIQUID GAS FEED APPARATUS