3/4″ GURU PC®


The ¾” thermostatic GURU PC®  valve is installed at the lowest point within the potable water-bearing system 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. It will automatically drain the passenger train car’s water tanks 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 power and heat are restored to the rail car, the valve will warm up and modulate closed, allowing the water tanks to be refilled before returning to service. Since the valve is completely mechanical, no electrical or air connections are required to operate.

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

To help prevent nuisance dumping, we recommend replacing the cartridge assembly approximately every 2 years if sluggish or marginal closing performance from testing is witnessed. We offer a replacement cartridge kit to assist ease of replacement without removal of the Tee Body.

The GURU PC® is NSF 61 Certified for use in potable water systems and shock and vibration tested to withstand harsh conditions. Compact, reliable, and in-line serviceable for ease of maintenance, the GURU PC® is the ideal solution to protect your passenger train toilet modules and galleys from freeze damage.


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 train 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
3/4″ GURU PC Rebuild Kit Installation and Maintenance Instructions
Railroad Brochure
GURU PC Case Study