In the gate area for non-pressurized casting gating ratio a:b:c? (gating ratio = a: b: c where, a = cross-sectional area of sprue, b: cross-sectional area of runner, c = total cross-sectional area of ingates).

In the gate area for non-pressurized casting gating ratio a:b:c? (gating ratio = a: b: c where, a = cross-sectional area of sprue, b: cross-sectional area of runner, c = total cross-sectional area of ingates). Correct Answer 1:4:4

The gating ratio may be of the order of 3:2:1 for pressurized gating system and for unpressurized gating system is will be in 1:3:2. The further differences between pressurized and non-pressurized gating system are tabulated below: S.No. Pressurized gating systems Unpressurized gating systems 1 Gating ratio may be of the order of 3:2:1 Gating ratio may be of the order of 1:3:2 2 Air aspiration effect is minimum Air aspiration effect is more 3 Volume flow of liquid from every ingate is almost equal Volume flow of liquid form every ingate is different 4 They are smaller in volume for a given flow rate of metal. Therefore, the casting yield is higher. They are larger in volume because they involve large runners and gates as compared to pressurized system and thus the cast yield is reduced. 5 Velocity is high, severe turbulence may occur at corners. Velocity is low and turbulence is reduced.