Do you mean the pinch-to-zoom in touch devices? If yes, you need to add the following meta in the header of your page:
<meta name="viewport" content="initial-scale=1.0, maximum-scale=1.0, width=device-width, user-scalable=no, user-scalable=0">
However, please note that iOS Safari no longer respcet user-scalable=no in the viewport because Apple wants to improve website accessilbity for those who need it. If you still need to disable pinch-to-zoon in iOS safari, a javascript solution is needed.
For double tab zoom, you will need to apply this CSS On individual elements.
touch-action: manipulation