The Model 18 Vacuum Relief Regulator from Fairchild is ideal for use in systems that need vacuum control that reaches a full vacuum. This relief valve makes use of the principle of balance of force to allow air from the atmosphere into the system by opening the relief valve when the set vacuum is exceeded. This way, the vacuum is lowered by air entering through the open relief valve. An aspirator tube is used to maintain stability of the regulated vacuum in changing flow conditions.
This tube adjusts the inner valve depending on the velocity of the flow. The control sensitivity of this regulator is less than 1/8 inch water column. There is a balanced supply valve that ensures consistency and accuracy. It offers a flow capacity of 68 m3/h and can handle 30 inHg, 762 Torr and 102 kPa maximum vacuum supply with 3 ranges. These ranges are from 4 to 30 inches of mercury, 140 to 1000 mBar and 14 to 100 kPa.
