Harwil HRQ12D Flow Switch 1/2" Mpt Long Stem Pilot Duty SPNO

Overview

Reliable mechanical flow monitoring for water systems. This 1/2 MPT long stem flow switch is designed for use in pool and spa systems, water heaters, boilers and general hydronic equipment where accurate flow detection is required to protect pumps and heating equipment.

Key Features

• 1/2 inch male pipe thread connection for direct inline installation
• Long stem design for use in deeper pipe runs and retrofit installations
• Durable construction for wet environments and continuous operation
• Simple mechanical operation with clear on off actuation for flow control and safety interlocks

Applications

• Pool and spa pump protection
• Flow interlock for pool heaters and gas-fired equipment
• Circulator monitoring in boilers and hydronic systems
• Commercial and residential water systems

Installation Tips

• Install in straight pipe run for best accuracy and ensure correct orientation per flow direction markings
• Use appropriate thread sealant on the 1/2 MPT connection and confirm stem clearance inside the pipe
• Verify compatibility with system media and temperature range before installation

Maintenance

• Periodically inspect for debris and scale that can affect actuation
• Test switch function after installation and seasonally where applicable

Why Choose This Flow Switch

Simple reliable flow detection for protection of pumps and heat exchangers. The long stem option makes this unit useful for retrofit installs where deeper insertion is required. Ideal for pool, spa and general hydronic applications where a mechanical flow contact is preferred.