Watts F121544 1.5″ LF174A Lead-Free 100 PSI Relief Valve 5,290K BTU

Description

The Watts F121544 is a 1.5″ LF174A series lead-free relief valve engineered to provide dependable overpressure protection for hydronic heating systems, boilers, and hot water supply applications. Built to the LF174A design standard, this valve delivers consistent, code-compliant performance where lead-free construction is required by plumbing codes and potable water regulations.

Key Features

• Lead-free (LF) construction for compliance with low-lead plumbing requirements
• 1.5″ connection size for high-flow commercial and industrial installations
• 100 PSI factory-set relief pressure for precise overpressure protection
• 5,290,000 BTU/hr (5,290K) rated capacity for large-scale heating systems
• Watts LF174A series — a trusted standard in commercial hydronic and steam relief applications
• Designed for reliable, automatic pressure relief to protect system components

Product Specifications

• Brand: Watts
• SKU / Part Number: F121544
• Model Series: LF174A
• Connection Size: 1.5″
• Set Pressure: 100 PSI
• BTU Capacity: 5,290,000 BTU/hr
• Construction: Lead-Free (LF)

Applications

• Commercial and industrial boiler systems
• Hydronic heating and hot water supply systems
• Installations requiring lead-free valve components per plumbing code
• High-capacity heating plants requiring 5,290,000 BTU/hr relief rating