Abstract: A gas system includes a container, a fitting, a gas tube, adsorbent, and a filter. The container stores gas under pressure. The fitting covers an opening of the container and maintains a seal with the opening of the container. The gas tube is inserted through a bore in the fitting such that a length of a portion of the gas tube inside of the container is at least one half of a length of the container. The portion of the gas tube in the container includes holes. The adsorbent is in a particulate form and adsorbs gas in the container. The filter covers the holes in the portion of the gas tube in the container. The filter permits passage of gas into and out of the gas tube and prevents passage of the adsorbent into the gas tube.