Oil level sight glasses GN 744 use the so called prismatic effect of a cat’s eye to display the oil level unaffected by oil colour or oil viscosity. The advantage of this effect is particularly obvious in the case of under or overfilling or for inspection under unfavourable light conditions.
The seal is housed in a radial groove in the aluminium body and hence cannot be lost. In addition it cannot be extruded when thigtening the sight glass.
Oil level sight glasses GN 744 can also be used on pressurised tanks. Data of pressure an vacuum pressure tests is available.
For mounting on walls of less than 4 mm thickness please use a fixing nut GH.