[cleszkie]

If you can pull on it and it opens, then you have something out of adjustment. Before you go and add a gate latches and padlocks, make sure the catch mechanisms are fully engaging the catches. If one or both mechanisms are not fully rotating into the closed position (where they grab the catch bar), then they will not lock out. This is usually caused by catch bars out of position (either up/down/or out).

Another posibility is that your lock cylinder in the handle is not actually lockinig, allowing you to rotate the catch mechanisms to the open position when you pull on the handle.