How to choose the right valve size for my water shutoff?

Other Devices & Integrations Climate Control & Temperature Sensors
#1

I am planning to buy a Fortrezz shutoff valve this boxing day and have a question:

If my water valve size is 3/4 inch, should I buy a 3/4 inch or 1" Fortrezz valve? My main water shutoff is as in the attachment. Do you think it is a 3/4 inch valve too? I do not trust my measurement.

Thanks.

#2

If your current valve size is 3/4" then you should buy a 3/4" Fortrezz valve - that is a very common size for a residential cold water supply pipe. While you could use a 1" valve with 3/4" pipe your plumber would have to install a pipe size adapter on both sides of the valve, and you wouldn’t gain anything by doing that.

The size of the valve you need is based on the nominal size of the pipe leading to and away from it. Copper pipe with a nominal size of 3/4" has an outside diameter of 7/8 of an inch - you can measure the diameter of the pipe feeding your valve to double check your installation.

Note - you might want to edit the name of the picture you posted to something that isn’t your home address.

#3
While you could use a 1" valve with 3/4" pipe your plumber would have to install a pipe size adapter on both sides of the valve, and you wouldn't gain anything by doing that.

Not quite true … it rare to find a valve that is FULL bore … So they often cause a restriction … this will be noticeable if you have low water pressure or you have high flow demands.

If you want to minimize pressure drop … I would increase by one size …

Note: There are some ball valves that are FULL bore … but as I said they are uncommon. They are often as expensive as the next size up as well.

#4

Ok. Thanks guys. I will consider about that.