{
  "$type": "site.standard.document",
  "description": "A vacuum operated flow control valve (20) is disposed in the vapor vent line from a fuel tank (12) to a vapor storage canister (28) connected also to the engine air inlet (40). The valve (20) has a diaphragm operator (58) of low permeability which is biased normally open to permit fuel vapor to…",
  "path": "/patents/1086637",
  "publishedAt": "2004-06-09T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B60K15/03519",
    "EATON CORP [US]"
  ],
  "textContent": "A vacuum operated flow control valve (20) is disposed in the vapor vent line from a fuel tank (12) to a vapor storage canister (28) connected also to the engine air inlet (40). The valve (20) has a diaphragm operator (58) of low permeability which is biased normally open to permit fuel vapor to flow from the tank (12) to the canister (28) during engine shutdown. Upon engine startup a vacuum is drawn in the canister (28) and the flow control valve (20) which closes preventing vacuum being drawn in the tank (12) thereby preventing tank collapse. During engine shutdown, if an ambient temperature drop creates a vacuum in the tank (12), the flow control valve (20) closes; however, an emergency umbrella relief valve (80) opens permitting reverse flow of vapor from the canister (28) to the tank (12) preventing excessive vacuum in the tank (12).",
  "title": "Fuel vapor vent system and low permeation vacuum operated shut-off valve therefor"
}