Hydraulic Pressure Transducers for Vulcanizing and Challenging Applications

Vulcanizing – the process of molding and hardening rubber with chemical treatments at a high temperature – is a critical step in the process of manufacturing quality, reliable tires for everyday use. A typical vulcanizer uses several hydraulic pressure systems to cure tires. These systems help power multiple parts of the machine, from molding the tire to transferring it to the next step in the manufacturing process.

 As raw tire rubber is molded into a shape that closely resembles its final state, a tire curing press uses the heat generated by steam along with pressure to mold the tire into its final form. It’s critical for the safety of the operators that the steam and pressure are evacuated from the curing press of the vulcanizer before it is opened.

 Vulcanizing is a great example of a challenging hydraulic application that experiences vibration, shock and high temperatures, one where hazardous approvals may be required. There are other examples of similar hydraulic applications in industries like construction, energy, and chemical manufacturing. In situations like these, it’s vital to select a transducer that meets all necessary performance standards.

 In my experience working with pressure sensors, I’ve been able to help thousands of customers ensure that they have the right transducer for the job. This article will help you understand the critical factors you should consider when selecting pressure transducers for challenging environments such as vulcanizing and other hydraulic applications that experience tough conditions.

Critical Factors for Pressure Transducers in Hydraulic Applications

There are many hazards that can impact the performance of a pressure transducer in hydraulic applications.  But three of the most challenging factors in these applications are hydraulic shock, vibration and pressure spikes or pulsations.  Each of these factors creates its own set of challenges, as I explain below.

Hydraulic Shock

Hydraulic shock is a pressure surge caused when a fluid or gas in motion is forced to stop or change direction suddenly.  These pressure surges are usually caused by external impacts on the system.  This produces a very fast and large amplitude spike in pressure, sometimes four to five times the normal maximum operating pressure of the system.  Due to the fast response time of most transducers (< 5 msec), these spikes can affect the performance and cycle life of the transducer.

Vibration

Vibration is a mechanical oscillation or noise that occurs in a system because of noise from motors, pumps, actuators, valves, hydraulic lines and other components.  Hydraulic vibration is mostly a fast and low amplitude pulse that also affects the performance and cycle life of a pressure transducer.  Vibration can cause wear in the mechanical components of a transducer leading to drift in the output signal of the sensor. 

Pressure Spikes

A pressure spike or pulsation, which is often referred to as water hammer, is a pressure surge caused when a fluid or gas in motion is forced to stop or change direction suddenly.  Pressure spikes are usually caused by a closed valve near the transducer.  This produces a very fast and large amplitude spike in pressure, usually many times the normal maximum operating pressure of the system.  Since a transducer is a dead-ended device, coupled with the fast response time of most transducers (< 5 msec), these spikes can affect the performance and cycle life of the transducer. 

In each of these cases, it's critical to make sure that the transducer is properly designed and located in the system to protect the sensors from these hazards.

Ashcroft’s E2 Pressure Transducers for Hydraulic Applications 

The Ashcroft® E2 pressure transducer is ideal for vulcanizing and other hydraulic applications with extreme or uncertain conditions. That’s because the E2 pressure transducer utilizes Ashcroft’s proven sensor technology to offer accurate, repeatable output in a package designed to provide long life and durability — making for a reliable transducer that will ensure operational safety and consistent performance from your hydraulic systems no matter what kind of stress they are placed under.

The E2’s stability and durability come thanks to its onboard sensing element, which uses a proprietary chemical vapor deposition (CVD) sensing technology. This process produces a sensor that provides precise and consistent output along with high reliability and performance across all mid to high-pressure applications. Since the sensing element is made from stainless steel it can be safely welded to an array of different pressure fittings to maintain a secure seal in your process.

This CVD sensing technology also means that the E2 can offer repeatability, durability and stability over a wide range of temperatures, with operating limits between -40 °F and 257 °F.

 The E2 pressure transducer also uses a unique external calibration process for adjusting the offset and span of the unit should it be required. Besides its presence in our general application E2G unit, this external calibration feature is also available in the E2F Explosion proof (flame proof) and E2S Intrinsically Safe (non-incendive) hazardous approved models of the E2 transducer product line.

Other Hydraulic System Applications for E2 Pressure Transducers

 In the specific case of vulcanizing, you’ll need a sensor that meets all the requirements of the hydraulic application. A few other examples of applications with tough requirements include:

• Heavy-duty hydraulic power equipment used in extreme weather conditions
  
• Load moment indicators (LMIs) and similar real-time load weighing systems critical for safety in major hauling applications
  
• With ranges as low as 0 to 1.5 psi, the E2 is ideal for monitoring tank level in your hydraulic system.

 The features of the E2 pressure transducers are designed to meet even the most extreme requirements of the hydraulic systems. Without the right pressure sensors, your systems are at risk of errors negatively impacting the pressure reading from the transducer, leading to inaccurate measurement.

Final Thoughts on Hydraulic Pressure Transducers for Challenging Applications

Vulcanizing during the tire curing process is just one of several applications that can benefit from reliable, high-performance pressure sensors. Now that you have a better understanding of the factors that go into selecting the right pressure transducer, you can research to find an option that fulfills your performance needs as well as your company’s budget. Stay mindful of these factors and you’ll be able to avoid errors and keep your hydraulic systems running smoothly and accurately.

 If you want to learn more about pressure transducers, check out some of our other blog posts:

Feel free to contact us today to talk to one of our industry experts and get your questions answered.

To learn more about selecting pressure transducers for your industrial applications, download our eBook: 5 Mistakes OEMs and System Integrators Make When Selecting Pressure Sensors.