Watts 8499 Multi-orifice Flow Control Valve 0.5 Inch Sweat

Product Description

The WATTS 8499 is a lead-free, multi-orifice flow control valve designed for tankless water heater installations. Built with a 0.5-inch sweat (solder) connection and a rotatable multi-orifice cylinder, it lets the installer dial in the correct flow rate from four fixed positions: 2.5, 3, 3.5, or 4 GPM. Controlling flow at the equipment inlet prevents excessive water velocity that causes inadequate heat transfer in on-demand heating systems. The valve body is constructed from lead-free alloy, keeping it compliant with current potable-water regulations. Maximum working pressure is 150 psi. Licensed plumbers and HVAC technicians working on residential or light-commercial tankless systems are the primary installers of this component.

This valve is sized and rated for 0.5-inch sweat piping commonly found in residential tankless water heater supply lines. The adjustable orifice settings accommodate a range of heater input ratings and flow demands, making the 8499 useful across multiple tankless unit models and flow scenarios. It is installed on the cold-water inlet line to the tankless heater, upstream of the unit, to regulate flow before it enters the heat exchanger. Proper flow control at this point directly affects the heater's ability to reach and hold target outlet temperature.

Key Features

• Multi-orifice cylinder allows field selection of 2.5, 3, 3.5, or 4 GPM without additional components
• Lead-free alloy construction meets current potable-water safety standards
• 0.5-inch sweat connections integrate directly into standard copper piping
• 150 psi maximum pressure rating suits residential and light-commercial supply lines
• Prevents insufficient heat transfer caused by excess flow through the heat exchanger

Compatibility

Designed as an OEM-style flow control solution for 0.5-inch sweat piping in tankless water heater installations where flow limiting is required at the cold-water inlet.

Installation Notes

Installation should be performed by a licensed plumber in accordance with local plumbing codes and the International Plumbing Code (IPC). Shut off the cold-water supply and depressurize the line before making any connections. Use standard soldering tools and lead-free solder appropriate for potable-water service when making sweat joints. Confirm the selected orifice setting matches the tankless heater manufacturer's recommended flow rate before commissioning the system.

Technical Specifications

• Connection Type: Sweat (solder), 0.5 inches
• Flow Rate Settings: 2.5, 3, 3.5, or 4 GPM (field selectable)
• Maximum Pressure: 150 psi
• Material: Lead-free alloy
• Application: Tankless water heater installations

Standard Information

• Brand: WATTS
• Manufacturer Part Number: 8499