Optional Water Efficiency Measure: May contribute to the 30 percent water efficiency requirement,
depending on the chosen WaterSense® Approved Certification Method (WACM),

Water pressure in supply main lines can reach 100 pounds per square inch (psi) or more. High water
pressure can damage plumbing piping, fixtures, and appliances, and can lead to increased water
consumption, premature equipment failure, and risk of leaks.
Most U.S. plumbing codes require pressure-regulating valves (PRVs, also called pressure regulators) on
domestic systems where the pressure of the supplied water exceeds 80 psi.
Single-family residences supplied by groundwater wells should use a pressure tank set at 60 psi. This
not only ensures optimal performance of the home and protects it from leaks, but conserves energy.
WaterSense recommends incoming service pressure to be between 45 and 60 psi to ensure efficient
use of water and proper system function. This water pressure is within the optimal pressure range for
water-using fixtures and appliances, while still reducing the amount of water used and risk to the
system compared to higher pressures.
CONFIRM that service pressure does not exceed 80 psi
by consulting with the public water supplier.
INSTALL a PRV downstream of the point of connection to
the water source and set the PRV to limit pressure to
between 45 and 60 psi.
CONSULT local plumbing codes to see if thermal
expansion, which can occur from installing a PRV since it
creates a closed system, needs to be addressed.
MAINTAIN fire sprinkler systems in accordance with
state and local codes and regulations.
• VERIFY the water pressure to the home or unit to
determine if the PRV, if installed, is set and working
o Attach a pressure gauge to a hose bibb, the cold-
water faucet for the washing machine hookup, or a
cold-water faucet on the first floor. Turn on the water
to the fully open position,
o If the home has multiple water supplies (e.g., an
independent source for irrigation), verify the water
pressure from each supply.
Direct-Acting Valves
The most common type of water pressure-
reducing valve is a direct-acting valve,
which consists of a globe-type body with a
spring-loaded, heat-resistant diaphragm
connected to the outlet of the valve that
acts upon a spring. Water entering the valve
is constricted within the valve body and
directed through the inner chamber, which
is controlled by an adjustable spring-
loaded diaphragm and disc. The minimum
flow through a PRV should be between 10
and 15 percent of the maximum desired
flow rate. Select a regulator for which
operating pressures fall within the middle
of its rated range, not based on the size of
the pipe to which it will be attached.
Learn More
Visit the Building America Solution Center
at https://basc.pnnl.gov/resource-
guides/service-water-pressure to learn
*NOTE: Consult with the Home Certification Organization for specific verification protocols.
This technical fact sheet is part of EPA's Technical Reference Manual for
WaterSense Labeled Homes. For the full document and other tools and	EPA-832-F-23-Q16
resources for homes, visit www.epa.gov/watersense/tools-and-resources.	July 2023