This valve has flow indication embossed on their body.
the gate valve is a very important one in flow measurement and also used to help the measure of flow. for example if you know the pneumatic comparator operation, you can easily under stand the gate valve. the gate valve is mainly used for to adjust the float in the tube to zero position or the clearance value.
Gate valves are used primarily for isolation, usually not for flow modulation. They are usually operated fully open or fully closed. Installing the valve with the arrow pointing in the direction of flow will have more to do with the tight sealing of the closed valve than with the operation when open. If the valve is to be installed in a pipeline where the flow is in either direction, pick the direction most important for good sealing. However, I do not recall seeing a flow arrow on a conventional gate valve.