Spring-Loaded Check Valve 1" D x 1-1/4" D Brass - Campbell FV-4FX5MT-LF The Campbell FV-4FX5MT-LF brass spring-loaded check valve is a precision-engineered, lead-free component designed to prevent backflow in residential and light commercial well, pump, and water systems. Constructed from solid brass with a machined exterior, it delivers superior corrosion resistance and long-term reliability in water, oil, and gas applications. The spring-loaded mechanism activates automatically under pressure, allowing forward flow while instantly sealing to stop reverse flow ? protecting pumps from damage caused by water hammer or siphonage. Its 1-inch inlet and 1-1/4-inch outlet provide smooth, unrestricted flow with minimal turbulence, and it operates effectively in both horizontal and vertical orientations. Rated for 175 PSI and 190F, it meets the demands of high-pressure well systems and is certified for potable water use. Features - Solid brass construction with machined surfaces for durability and leak-free performance - Spring-loaded design provides automatic, pressure-driven closure to prevent backflow - Lead-free brass complies with federal and state plumbing codes for potable water systems - 1 in. inlet and 1-1/4 in. outlet ensures compatibility with standard well piping and pump outlets - Operates in horizontal or vertical mounting orientations for flexible installation - Rated for 175 PSI maximum pressure and 190F maximum temperature - Prevents pump damage from water hammer, siphonage, and reverse flow - Smooth internal bore minimizes flow restriction and reduces energy consumption - No tools required for installation ? threads directly into standard pipe fittings - Resists corrosion from water, oil, and gas environments - Boxed for clean transport and storage prior to installation - Designed for use in deep well, shallow well, and submersible pump systems Specifications - Brand Name: Campbell - Model Name: Campbell FV-4FX5MT-LF - Product Type: Spring Loaded Check Valve - Material: Brass (Lead-Free) - Inlet Diameter: 1 in - Outlet Diameter: 1-1/4 in - Maximum Pressure: 175 PSI - Maximum Temperature: 190 F - Activation: Pressure-Driven - Mounting Orientation: Horizontal or Vertical - Valve Type: Spring Loaded Check Valve - Weight: 0.7 lb - Packaging: Boxed - Certification: Lead-Free, Potable Water Compliant - Country of Origin: United States - UPC: 088409040094 - GTIN: 00088409040094 - Manufacturer: Campbell Manufacturing Product Application The Campbell FV-4FX5MT-LF check valve is used by well system installers, pump technicians, and homeowners maintaining residential and light commercial water systems. Essential for protecting submersible or jet pumps from reverse flow and water hammer, it prevents costly damage and extends pump life by ensuring one-way flow from the well to the pressure tank. Ideal for deep well, shallow well, and irrigation systems where consistent pressure and backflow prevention are critical, it installs quickly on discharge lines and requires no maintenance. Professionals trust its brass construction and reliable spring mechanism to deliver consistent performance under pressure ? delivering the confidence that water systems remain efficient, safe, and protected from contamination and mechanical failure.