A device for holding an IV tube in a pumping apparatus and for selectively occluding the tube when the door of the pumping apparatus is opened, to prevent free flow of fluid in the tube. A flange provided on a sliding clamp is designed to prevent inadvertent finger slippage causing pushing of a tab positioned in the sliding direction from the flange, resulting in undesirable fluid leakage. The flange is made slip-resistant using a textured surface, having a concave shape, or having an angled top portion to prevent finger slippage or having a concave setback to guide a finger when pushing the sliding clamp.
