H.C. BT-T40LF-38 Under Counter Thermostatic Mixing Valve – 3/8 in Brass, ASSE 1070, IAPMO cUPC

Overview

The H.C. BT-T40LF-38 is designed for under-sink use, delivering a stable, user-friendly way to blend hot and cold water to a chosen temperature. It supports a selectable range from 80°F to 120°F (27°C to 49°C) and accommodates flow from 0.25 gpm up to 2.25 gpm (1.0 to 8.5 L/min). The compact brass body is lead-free, aligning with contemporary installation standards and safety expectations.

With a rapid-response thermostatic element, the valve reacts to changes in outlet temperature to maintain a consistent delivery. This means steady performance even when more or less water is drawn or when incoming supply conditions shift. In the event of a cold water supply issue, the valve can reduce outlet flow to a trickle for safety and control.

Key benefits

• Precise temperature control with a fast-responding thermostatic element.
• Wide selectable temperature range and flexible flow options for multiple applications.
• Lead-free brass body supporting compliant installations and long-term reliability.
• Integrated checks and screens guard against debris and cross-flow between inlets.

Additional features include an inlet compression connection to 3/8" OD tube and an optional cold water bypass for configuration flexibility. The model ships with integral check valves on both inlets to prevent cross-flow and maintain system integrity.

Real-world use cases

• Kitchen and bar sinks where steady warm water improves comfort and efficiency.
• Commercial wash stations requiring consistent temperatures despite fluctuating supply pressures.
• Maintenance-friendly installations that minimize accidental temperature changes with a locking nut on the adjustment stem.

Performance and compliance

Designed for reliability, the BT-T40LF-38 meets key industry standards and features NSF 61 and NSF 372 compliance, ASSE 1070 compliance, and IAPMO cUPC compatibility. The combination of rapid temperature response, stable outlet temperature, and robust protection against cross-flow makes it a practical choice for many hard-water and variable-pressure environments.

In summary, this valve offers a thoughtful balance of control, safety, and durability for under-counter installations, with flexibility to suit a range of plumbing layouts and usage scenarios.