Markets & Applications


Fulton Bellows has a strong presence in the automotive industry providing innovative solutions that monitor fluid temperature and regulate flow control valves, thereby optimizing the performance and efficiency of various automotive systems.


Our thermal actuators, powered by wax motors, play a pivotal role in monitoring fluid temperature and actuating flow control valves. By precisely regulating the temperature of the respective systems, we help enhance the overall efficiency and functionality of vehicles.

In pick-up trucks and other heavy-duty vehicles, maintaining optimal transmission oil temperature is crucial for efficient operation. Our thermal actuators work seamlessly with transmission oil coolers, ensuring that the fluid temperature remains within the desired range. This not only helps extend the lifespan of the transmission system but also improves fuel economy and enhances performance.

While cooling system thermostats may seem like a legacy application, at Fulton Bellows, we continue to deliver cutting-edge solutions in this area. In fact, we are proud to supply an Original Equipment Manufacturer (OEM) thermostat, demonstrating our commitment to excellence. Our thermostats effectively regulate the engine coolant temperature, preventing overheating and maintaining the optimal operating conditions for the engine.

Over-the-road tractors often face challenging weather conditions, particularly during cold winters. Our diesel fuel heaters address this issue by providing reliable and efficient heating solutions. By preheating the diesel fuel, our heaters improve the combustion process, resulting in smoother engine operation and reduced emissions. Additionally, our fuel heaters help prevent fuel gelling, which can impair the performance of diesel engines in extremely low temperatures. With Fulton Bellows’ diesel fuel heaters, truckers can experience enhanced reliability and performance during their long-haul journeys.

Fulton Bellows takes pride in its contributions to the automotive industry. Through innovative thermal actuators, we enable precise monitoring of fluid temperature and regulation of flow control valves, leading to optimized performance and increased efficiency in automotive systems.

Basic and Common Applications

Shaft Seal

Prevents leakage around a revolving shaft. Spring pressure holds nose of seal against shoulder on shaft. Another type rotates with shaft and seals against a stationary plate.

Pressure Motors

Convert pressure effects into controlled movement or force. Pressure may be applied inside the bellows or outside the bellows in a cup structure, the latter being preferred. The floating head is usually provided with a limit stop when overload protection is needed.

Flexible Joint

Provides a means to seal a flexible joint or mechanical movement of levers, linkage, etc. against leakage where the movement must be conveyed outside enclosure. “P” optimum position of pivot.

Aneroid Assemblies

An aneroid assembly is a pressure motor where one side of a bellows assembly (inside the assembly illustrated) is evacuated to form a constant reference pressure against which the changing pressure on the other side is measured and used to produce predictable stroke. A spring for rate control and a stop to prevent excessive stroke from the resulting one atmosphere pressure differential usually are required.

Expansion Chamber

This type of assembly is employed to absorb thermal or pressure expansion. With suitable heads, it may be used as a reservoir for a liquid or gas. Examples: Oil reservoir for electrical cable joint and thermal expansion compensators on oil-filled transformers.

Thermostatic Motors

Similar to pressure motors. Pressure supplied by a sealed fill of thermo-sensitive liquid or gas. Thermal effect may be received either on the bellows element direct or at a remote bulb for transmission through flexible tubing. Widely used to operate valves, switches, etc., in response to temperature changes.

Remote Transmission

Two bellows assemblies joined by a tube for hydraulic transmission of motion or power. With bellows system solid filled, linear motion of one bellows is transmitted instantly and in equal degree to remote bellows, both bellows being provided with limit stops when overload protection is needed.

Expansion Joints

Packless and leakless construction is used to absorb thermal expansion of pipe lines carrying steam, water, etc., or, to absorb vibration or provide a flexible connection.

Packless Construction

Diagram illustrates packless valve construction. Same principle is used to seal steam movement or adjustment in many types of apparatus.