3/4″ GURU PC®


The ¾” thermostatic GURU PC® passenger cars freeze protection valve is installed at the lowest point within the potable water-bearing systems on a passenger train car to prevent the water from freezing when the car heat is turned off.

This self-operating freeze protection valve monitors ambient temperatures and will automatically drain the passenger car’s water system if the outside air temperature falls to the valve’s set-point, 35°F (1.7°C), ultimately preventing a system freeze up and thousands of dollars in damage.

Once the car heat is restored and the valve warms up it will modulate closed, allowing for the passenger car’s water tank to be refilled before returning to service. Since the valve is completely mechanical, no electrical or air connections are required for the valve to operate.

To avoid a delay in refilling the water system and getting the car back into service after a valve activation we recommend using our electric heater assembly. The heater attaches to the thermal actuator on the valve and will warm it up quickly once power is restored to the car. This allows the valve to close and the system to be refilled as quickly as possible after a drain occurrence.

NSF 61 Certified and shock and vibration tested, the GURU PC® passenger cars freeze protection valve is compact, reliable, and in-line serviceable for ease of maintenance.

Design Features

  • Exclusive self-actuating Thermoloid® blend paraffin wax actuator
  • Low lead brass/bronze
  • Dual-port seals
  • In-line serviceable
  • Available with an electric heater assembly for quicker refills


  • Self-operating – no external power source required
  • Eliminates costly freeze damage in a passenger car
  • High flow design for rapid draining
  • Easy installation
  • Minimal maintenance required
  • NSF 61/372 certified
  • Shock & Vibration tested

Heater Assembly Features

  • 2 LED lights for easy visual check of power and heater
  • Fully encapsulated PC board
  • Self-limiting heater
  • No moving parts to wear
  • Minimal electrical noise
  • Easy installation/removal with one hand
  • Heaters available: 120VAC/74VDC & 230 VAC

GURU PC with Heater Assembly Passenger Cars Freeze Protection Valve


  • Size: ¾” NPT
  • Maximum Operating Pressure: 60 PSIG (4.1 BAR)
  • Full Open Temperature: 35°F (1.7°C)
  • Closing Temperature: 45°F (7°C)
  • Operating/Storage Temperature Range: -67°F – 160°F (-55°C – 71°C)


3/4″ GURU PC Product Sheet
3/4″ GURU PC Installation and Maintenance Instructions
Railroad Brochure