Locomotive Freeze Protection Overview
The GURU® DL2.1 valve uses ThermOmegaTech’s self-actuating Thermoloid® thermal actuator to provide automatic freeze protection. The design supports easy system refill and allows the GURU® valve to be maintained and tested in the field.
The GURU® DL2.1 is used by Class I, Class II, Class III and locomotive OEMs throughout North America.
Design Features
- Exclusive Thermoloid® paraffin wax actuator is the only wetted component, allowing the valve to respond to cooling water temperature rather than surrounding air temperature
- Slotted actuator design helps prevent nuisance releases when refilling the cooling system with cold water
- The design isolates stainless-steel moving parts from cooling water chemicals and debris
- Paint mask minimizes accidental paint-ins during locomotive service
- A cartridge knob supports installation and removal in restricted locations
- Extra port for temperature bushing
- Optional domed anti-tamper cap eliminates the ability to tamper with the valve resetting stem
Diesel Locomotive Freeze Protection Applications
The GURU® DL2.1 is used in water-cooled diesel locomotive systems, including engine cooling circuits, standby diesel heating circulators, cab heater lines, onboard tanks, and associated piping.
Maintenance & Rebuild Support
ThermOmegaTech® offers a GURU® Rebuild Program to support ongoing maintenance of GURU® DL2.1 rail freeze protection valves and help keep fleet equipment in service.
GURU® Rebuild Program
GURU® DL2.1 Resources
Product Literature
Specification & Installation
Additional Resources
Technical Specifications
- Available Configurations: 1 1/4” NPT, tee, cross-body, and grooved or flat faced flanged tee
- Release Temperatures: 35°F (1.7°C) or 40°F (4.44°C)
Ordering
| PART NUMBER | DESCRIPTION |
|---|---|
| 481-04-82-CART | 35°F RELEASE DL 2.1 CARTRIDGE ONLY |
| 481-04-81V-CART | 40°F RELEASE DL 2.1 CARTRIDGE ONLY |
| 487-04-88 | 35°F RELEASE DL 2.1 TYPE-S |
| 487-04-87 | 40°F RELEASE DL 2.1 TYPE-S |
| 482-04-88 | 35°F RELEASE DL 2.1 TYPE-T |
| 482-04-82 | 40°F RELEASE DL 2.1 TYPE-T |
| 483-04-88 | 35°F RELEASE DL 2.1 TYPE-FL – GROOVED FLANGE QUAD SEAL |
| 483-04-83 | 40°F RELEASE DL 2.1 TYPE-FL – GROOVED FLANGE QUAD SEAL |
| 483-04-88-GX | 35°F RELEASE DL 2.1 TYPE-FL-GX – FLAT FACED FLANGES |
| 483-04-83-GX-V | 40°F RELEASE DL 2.1 TYPE-FL-GX – FLAT FACED FLANGES |
| 475-009100-035 | 35°F RELEASE DL 2.1 TYPE CR/FL/P – CROSS VALVE w/ PLUG & GROOVED FLANGE QUAD SEAL |
| 475-008100-035 | 35°F RELEASE DL 2.1 TYPE CR/FLGX/P – CROSS VALVE w/ PLUG & FLAT FACED FLANGES |
| 475-001110-035 | 35°F RELEASE TYPE-S ANTI-TAMPER CAP |
| 475-001010-040 | 40°F RELEASE TYPE-S ANTI-TAMPER CAP |
How the GURU® DL2.1 Valve Operates
The GURU® DL 2.1 locomotive freeze protection valve operates as an automatic freeze-out plug with one crucial difference: The GURU® cartridge releases itself from its body at a pre-set water temperature rather than being forced out by the tremendous pressure of expanding ice.
When released, the cartridge creates an almost full 1-inch opening that allows the locomotive cooling system to drain rapidly before expanding ice can damage water lines, tanks, or other components. Because the thermal actuator responds to cooling water temperature rather than surrounding air temperature, the valve remains closed while circulating coolant remains above its release temperature.
Resetting and Refilling
After activation, the valve is reset by reheating the cartridge and reinserting it into the hex nut.
During system refill, the GURU® Flag and Clip or GURU® Flag and Key can be used to prevent cold refill water from prematurely releasing the cartridge. The tools also provide a visible indication that the refill procedure is underway and help avoid temporary methods that could inadvertently remain installed when the locomotive returns to service.
Once the cooling system is filled and reheated, the valve automatically rearms for freeze protection.
