Wax Thermostatic Element LGX069
The LGX069 Wax Thermostatic Element is the most high-performance model in the Legom wax element range, combining the highest maximum temperature rating, the longest total stroke, and a strongly accelerating actuation profile concentrated in the 66°C to 82°C primary activation window. Built with Legom’s proprietary patented wax formula, it delivers consistent, repeatable stroke actuation across a rated lifespan of 100,000 cycles. It has passed European product certification by accredited institutions including ACS and WRAS.
With a maximum working temperature of 135°C, a total stroke ceiling of 16.5mm across the full 50°C to 135°C span, and a maximum load of 200N, the LGX069 surpasses every other Legom model in each of these three dimensions simultaneously. Its stroke profile is sharply accelerating: from ≤1.5mm in the initial 66°C~69°C band through 3mm at 69°C~75°C to a rapid 8.1mm between 75°C and 82°C — delivering the majority of its working stroke in just a 7°C window. Constructed from copper with a unique spring rate of 4N/mm.
Key Benefits
- Highest maximum temperature in the Legom range – Rated to 135°C maximum, significantly above the 90°C or 100°C ceiling of all other Legom models, enabling deployment in high-temperature industrial, automotive, and process heating applications
- Longest total stroke in the Legom range – Total stroke ceiling of 16.5mm across 50°C to 135°C is more than double the next highest model (LG0304 at 6.5mm), providing maximum valve travel for assemblies requiring large piston displacement
- Highest maximum load in the Legom range – Maximum load of 200N, shared only with the LGX075, enabling integration into heavy-duty valve assemblies with the stiffest return springs
- Sharply accelerating stroke profile – Stroke builds slowly from 66°C then accelerates dramatically to 8.1mm between 75°C and 82°C, concentrating the majority of valve travel within a narrow 7°C critical window
- Unique 4N/mm spring rate – The only Legom model with a 4N/mm spring rate — between the standard 5N/mm and the light-duty 1N/mm — providing a distinct mechanical balance suited to this element’s high-temperature, high-force application profile
- ACS and WRAS certified – Passed European experimental institution product certification, confirming suitability for potable water and HVAC applications in international markets
- Rated for 100,000 cycles – Exceptional service life verified through rigorous lifecycle testing at high-temperature operating conditions
- OEM and ODM customization available – Temperature range, working stroke, and maximum load can be customized for specific high-temperature application requirements
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | LGX069 |
| Material | Copper |
| Maximum Load | 200N |
| Minimum Load | 45N |
| Testing Load | 52N |
| Spring Rate | 4N/mm |
| Maximum Temperature | 135°C |
| Stroke | L = 4.4 ± 0.4mm at 66°C, 52N |
| Lifespan | 100,000 cycles |
| Certification | ACS, WRAS |
Temperature vs. Stroke
| Temperature (°C) | Stroke (mm) |
|---|---|
| 66°C ~ 69°C | ≤ 1.5 |
| 69°C ~ 75°C | 3.0 ± 0.3 |
| 75°C ~ 82°C | 8.1 ± 0.4 |
| 50°C ~ 135°C | 16.5 (Max) |
Stroke values measured during heating-up cycle. Cooling-down cycle may exhibit slight hysteresis typical of wax thermostatic elements. The 50°C~135°C row gives the total stroke ceiling across the full operating span. Refer to the Temperature VS. Stroke curve in the Datasheet for the complete graphical representation.
Application & Use Cases
- High-temperature thermostatic mixing and safety valves – The 66°C to 82°C primary actuation window and high force output make the LGX069 suited for thermostatic assemblies in high-temperature hot water systems, industrial heat exchangers, and process heating circuits where large valve travel is required
- Automotive engine cooling systems – Applied in engine thermostats and cooling circuit controls for high-performance or heavy-duty engines where the thermostat must deliver substantial valve opening with high force across the 66°C to 82°C warm-up range
- Industrial process heating control – Integrated into thermostatic valve assemblies for industrial heating circuits where fluid temperatures operate across the 50°C to 135°C range and the valve mechanism requires maximum stroke and force output
- High-temperature HVAC and boiler systems – Used in thermostatic control assemblies for high-temperature hot water heating circuits where operating temperatures exceed the 90°C ceiling of standard Legom models
- Shipping and marine engine systems – Applied in large marine engine cooling thermostats and fluid management systems requiring high-force, large-stroke actuation at elevated operating temperatures
- Military and specialty high-temperature applications – Suitable for demanding environments requiring self-acting, high-force, long-stroke thermostatic control at temperatures up to 135°C without electrical dependency
Installation Notes
- The LGX069 must be installed in direct contact with the fluid whose temperature it is intended to sense, ensuring accurate response across the full 50°C to 135°C operating range
- Ensure the element is fully immersed in the flow path. Given the high total stroke of 16.5mm, the host valve mechanism must provide sufficient axial travel to accommodate the full piston displacement without mechanical obstruction
- Do not expose the element to temperatures exceeding 135°C, the highest maximum temperature rating in the Legom range. Sustained exposure above this limit may permanently degrade the wax charge
- The LGX069 has a maximum load of 200N. Verify that the host valve mechanism does not impose forces beyond this limit during full stroke operation
- The spring rate of 4N/mm is unique in the Legom range. Ensure the host valve return spring is designed around this specific spring stiffness to achieve accurate piston reset on cooling
- The host valve or actuator assembly must provide adequate spring-back force above the minimum load of 45N to reset the piston on cooling
- For OEM integration, confirm three key parameters in writing before finalizing the order: temperature range, working stroke, and maximum load
Frequently Asked Questions
What makes the LGX069 the most extreme model in the Legom wax element range?
The LGX069 holds the top position in three of the most important performance dimensions simultaneously. First, maximum temperature at 135°C versus 90°C to 100°C for all other models. Second, total stroke at 16.5mm versus 6.5mm as the next highest (LG0304). Third, maximum load at 200N, shared only with the LGX075 boiler element. No other single Legom model combines all three of these extreme specifications. It also has a unique spring rate of 4N/mm not found in any other model, and delivers the highest single-band stroke in the entire range at 8.1mm within just the 75°C to 82°C window.
How should I read the four-row stroke table?
The first three rows describe the primary actuation window in sequence. The first row (66°C~69°C, ≤1.5mm) shows the minimal initial stroke as the element begins to activate. The second row (69°C~75°C, 3.0mm) shows accelerating stroke as temperature rises. The third row (75°C~82°C, 8.1mm) marks the peak actuation zone where the vast majority of working stroke is concentrated in just 7°C. These three rows are incremental values per band, not cumulative. The fourth row (50°C~135°C, 16.5mm max) gives the total stroke ceiling from the beginning of any response activity to the maximum temperature.
What certifications does the LGX069 hold?
The LGX069 has passed European experimental institution product certification under ACS and WRAS standards, confirming its suitability for use in drinking water systems and broader HVAC and plumbing applications in certified markets.
What is the expected service life of the LGX069?
The LGX069 is rated for 100,000 actuation cycles, supporting long-term deployment in high-temperature installations across the full 50°C to 135°C operating range.
How does the LGX069 compare to the LGX075 boiler element?
Both the LGX069 and LGX075 share a 200N maximum load. The key differences are: the LGX069 is ACS and WRAS certified while the LGX075 is not; the LGX069 activates from 66°C while the LGX075 starts from 80°C; the LGX069 has a higher maximum temperature at 135°C versus 99°C for the LGX075; and the LGX069 delivers a much larger total stroke of 16.5mm versus 6mm for the LGX075. Choose the LGX069 for applications requiring maximum stroke and extreme temperature range. Choose the LGX075 for boiler-specific applications where ACS/WRAS certification is not required and the activation must be concentrated near boiling point.
Can the LGX069 be customized for different temperature or stroke requirements?
Yes. Legom offers full OEM and ODM customization. If your application requires a different activation temperature, working stroke, or load specification, the engineering team can develop a customized solution. Written confirmation of three key parameters is required before any customization project begins: temperature range, working stroke, and maximum load.
OEM & ODM Customization
Legom supports full OEM and ODM services for the LGX069 Wax Thermostatic Element. Our engineering team can customize the activation temperature range, working stroke, and maximum load to match your product requirements. Before any commitment, written confirmation of three key performance parameters is required: temperature range, working stroke, and maximum load. All customization projects are handled with strict confidentiality. Contact us via WhatsApp or info@legomsmart.com.
Datasheet
Product information last reviewed by the Legom Technical Team. For the most current specifications, refer to the official datasheet or contact our sales team.
Custom OEM & ODM Solutions
Legom is a direct manufacturer offering end-to-end OEM and ODM services. With our in-house engineering and production capabilities, we work closely with distributors and system integrators to deliver fully customized solutions under strict NDA.
