Question Plumbing help

[Diveshaman]

Can anyone help with this situation I have. I never noticed before but recently when researching a potential plumbing change I am going to make when I upgrade my sump I noticed I had cracked unions just below the bulkhead on my Red Sea Reefer 300XL. I want to get these replaced and wanted to confirm if anyone has altered their metric plumbing of Red Sea to standard and if you know for sure exact sizes I will need for my set up? From literature I am seeing I have a 32mm Main Drain return. I am also seeing I have a 25mm Emergency Overflow and literature says return is a 16mm but at glance it looks to be same size as the emergency overflow and 25mm but again not markings to confirm only literature in manual from Red Sea. I want to simply transition from metric to standard right below bulkhead. Can I use a 32mm to 1” transition union for this main drain transition. And the same can I use a 25mm to 1” transition union for the emergency overflow and return? I can find the 32mm to 1” but can only find 25mm to 3/4” which isn’t a big deal I can transition from 3/4”-1” no problem.
Please let me know if you have experience and how best to accomplish what I am looking to do here which is switch everything metric to standard from cracked threaded cap in attached photo to below. Looking to have all 3 in 1” and how best to accomplish this. Also if switching the overflow reg out which is best a ball valve, gate valve or other? Thanks in advance for your time on this. Appreciate your help getting this figured out with least amount of fittings as possible

 

[DC Reefer]

Sounds like you have it figured out. I would go with the gate valve for the overflow. For the emergency overflow is the 1" preference just for aesthetics as you could eliminate one fitting by keeping it at 3/4 which should be more than sufficient for flow.