February 18, 2025

How to Connect the Right Size PEX Pipe to Municipal Water Meters

By Justin Churchill

When is a Water Meter Typically Installed in a Home? 

In a new home, water meter installation typically occurs during the final stages of construction, after installation and testing of the plumbing system but before final occupancy inspection. 

After installation and testing of the home’s plumbing system, including pipes, faucets, and fixtures, then the water meter installation can begin. At this stage, the construction is far enough along to ensure water is flowing through the system properly. 

Water meter installation usually happens before the city or municipality performs the final inspection. The inspection ensures the water system supply complies with building codes and is ready for use. Having the water meter in place is a key part of this process.  
 

Who Installs the Water Meter? 

The water meter installer can vary depending on the jurisdiction. If the home connects to a public water supply, the utility company will either send a technician to install the water meter or provide the water meter to the plumber or subcontractor to install and connect to the municipal water supply.  
 

Who Controls Water Meter Standards? 

In the USA, the American Water Works Association (AWWA) controls water meter standards. This industry association has specific standards for water meter threads in the United States. If you are new to the waterworks or metering industry, meter and meter connection sizing can be confusing.  
 

How Do You Size a Water Meter with PEX? 

Meters are sized based on the internal flow capacity, not the outer diameter of the meter threads. This means the threads on the meter are typically one size larger than the size of the meter. For example, the thread on a ¾" meter is actually 1" NPSM. 
 

Refer to the chart below for appropriate meter adapter sizing.