@KayKay 

I’m not sure what template for Klaviyo flow you used exactly but anyway it all depends on the filters and not just the trigger.

If the flow triggered by placed order metric has no filters this flow will repeat every time people place an order.

If you want people to be receiving this flow only on their first next order you can add flow filter ”has never been in this flow before”
Or if you want people to receive it lets say ever 30 days you can add flow filter “has not been in this flow in the last 30 days”
It all depends how you like this flow to work
You can also add some filters in a maner this flow to work only for people who make their 1st and 2nd order and for that you will add 2 filters. Placed order equals 1 over all time OR placed order equals 2 over all time.
There are a lot of other possibilities to limit this flow to but as I said without filters everyone will enter it every time they place an order.

Hey @KayKay 

Welcome to the Klaviyo Community! We are so glad you joined! 

Thank you @Bobi N., as always you are right on the money! Understanding the flow trigger and filters  would be the best way to make sure your emails are only sending as often as you want your customers to receive them, especially if they are making numerous purchases within a short amount of time!

Bobi’s suggestions are exactly what i would recommend to help filter out customers who are currently or have recently been in the flow! I created an example that you can see above based on a couple of his suggestions. 

Thanks again to you both for being a vital part of the Klaviyo Community experience, we appreciate you!

Thank you @Bobi N. and @stephen.trumble, much appreciated! That answered my question, thanks very much.