Industrial Process Pressure Transmitters

One of many variants of industrial pressure transmitters.
Image courtesy Yokogawa USA

The measurement and control of fluid pressure is ubiquitous throughout many industrial processes. Measurements of pressure, directly and indirectly, provide real time information about what is happening in places that cannot be seen, such as inside a pipe, tank, or machine. The very nature of “process” suggests movement and change, the control of which is necessary to produce a consistent desirable outcome. Industrial pressure transmitters employ specific technologies and physical principals to derive a measurement of process pressure, then deliver or transmit, the measured value to a controller or recording device.

Fluid pressure tells a process operator much about what is currently happening. The pressure variable can be used to determine, among many industrial process elements:

• Degree to which the process is conforming to a recipe or specification
• Whether machinery is performing within its specified operation range
• If conditions of the process remain within the bounds established for safety
• A quantity measurement of flow, mass, or volume

Global industrial processes have widely varying physical arrangements, operating environments, and measurement requirements. Manufacturers of industrial pressure transmitters have responded with an immense array of transmitter technologies, arrangements, and configurations. When selecting the best suited pressure transmitter for your application, consult a sales engineer and consider some of the following:

• Signal requirements – Type, distance, possible sources of interference
• Device environment – Hazards, extreme conditions of temperature or corrosion
• Accuracy and stability of measurement
• Response time to changes in the process condition
• Ratings and certifications required for the device
• Configuration, arrangement, and mounting aspects of the transmitter device

Explore the differing technologies and how they can be best applied to implement or improve your process. Experienced sales engineers are a useful sounding board for discussing your needs. Share you process measurement challenges with them and leverage your own knowledge and experience into an effective solution.

Asset Condition Monitoring for Major Equipment

Asset and equipment monitoring promotes the maximizing
of productivity by reducing downtime.

Minimizing machine or system downtime, for whatever cause, is a common productivity and financial goal of industrial processing of all types. Lost production time can never be recouped, and unplanned equipment outages can cost millions. There is real benefit to be had from monitoring operational aspects of machinery and systems in real time.

Asset condition monitoring, as the name implies, is the process of continually monitoring a machine or piece of equipment with the intent to alert operators to anomalies in machine function. Data gathered can also be used to define a normal operating envelope and show trends that may indicate a need for service. The goal, ultimately, is to repair, adjust or maintain prior to and avoiding outright failure. Key indicators of failing equipment can be changing values in vibration, noise or temperature measurements. Monitoring these and other variables, some derived at very localized and specific points, provides key indicators of the condition of the machine. By evaluating trends in the data, intelligent systems can provide health information about the equipment and assist in the early detection of possible faults or failures.

Implementation of asset condition monitoring is benefiting manufacturing plants and process industries such as chemical, petrochemical, pulp and paper, power generation, wind turbine, and oil and gas. Not only can it save money from protecting against unplanned outages, but condition monitoring also improves productivity, quality and profitability.

GE's Bently Nevada 3500 Monitoring System provides continuous, online monitoring suitable for machinery protection and asset condition monitoring applications. It is the company's most capable and flexible system, with a traditional rack-based design. The useful features of the system are numerous, and it delivers advantages not provided in other systems. Share your major asset monitoring challenges and plans with a systems specialist, and leverage your own knowledge and experience with their product application expertise to implement an effective solution.

Industrial Machinery and Asset Condition Monitoring from Classic Controls, Inc.

Process Instrumentation Selection Tool

Yokogawa's Process Instrumentation Selection
Tool saves time when searching for the right
process measurement instrument.
Image courtesy Yokogawa

Yokogawa Corporation of America, an industry recognized source for innovative process measurement and control products, has made available an easy to use product selection tool for those navigating through the company's extensive product offering. The Product Finder is a great time saver that enables a user to quickly locate product and technical information on Yokogawa products that meet the user's selected criteria.

Let's step through a quick example. You will see how this quick and easy to use tool saves time by navigating quickly to the website pages detailing products meeting your requirements.

The Product Finder is accessible through a number of links throughout Yokogawa's network of Reps. Clicking the link lands you on the start page of the Product Finder. For this example, I am going to search for a flow meter with the following characteristics:

• Mass flow measurement 
• Non-conductive liquid
• Accuracy of 1%
• Flow measurement device must have an integral transmitter
• Tri-clamp connections

Above, I declared my location as United States. The next step, shown below, is to select "Flow" as the measurement parameter. You will see in the drop down menu that there are many measurement elements that can be selected, with Yokogawa products for each.

My selection of "Flow" returns a list of all the company's flow measurement devices, of which there are many (this cropped screenshot, shown below, only shows four, but there were many more) . This is where the selector really helps you. Instead of examining several or many different models, the user can focus the search by adding more product characteristics. You can see the list of prompting questions on the left side of the page. Answering these will narrow the search results to the show only the products meeting all the criteria specified by the user.

The next image (below) shows selections of all my sample product attributes entered on the left column. Note that there is now only a single product that matches all of my sample criteria. The whole process took less than two minutes. By clicking on the "View More Details" button below the product image, I gain access to all of the available technical, support, and product data for my selected flow measurement device.

The process instrumentation experts at Classic Controls are available to provide additional help in meeting your process measurement challenges in Florida, Puerto Rico and the Caribbean. Combine their product knowledge and expertise with your process know-how for the best solutions.

Filled Impulse Lines With Pressure Sensors or Gauges

Pressure transmitters and gauges are often installed
with impulse lines.
Image courtesy Yokogawa

Pressure sensors intended for use in industrial process measurement and control applications are designed to be robust, dependable, and precise. Sometimes, though, it is necessary or beneficial to incorporate accessories in an installation which augment the performance of pressure sensors in difficult or hazardous environments. There are some scenarios where the sensor must be isolated from the process fluid, such as when the substance is highly corrosive.

A way to aid pressure sensing instruments in situations where direct contact must be avoided is by using a filled impulse line. An impulse line extends from a process pipe of vessel to a pressure measurement instrument or sensor. The line can have a diaphragm barrier that isolates the process fluid from the line, or the line can be open to the process. There are best practices that should be followed in the design and installation of an impulse line to assure that the line provides a useful transmission of the process pressure to the sensor and whatever degree of isolation or protection is needed remains in effect.

The filled impulse line functions via the addition of a non-harmful, neutral fluid to the impulse line. The neutral fluid acts as a barrier and a bridge, allowing the pressure sensing instrument to measure the pressure of the potentially harmful process fluid without direct contact. An example of this technique being employed is adding glycerin as a neutral fluid to an impulse line below a water pipe.

Glycerin’s freeze point is lower than water’s, meaning glycerin can withstand lower temperatures before freezing. The impulse line connected to the water pipe may freeze in process environments where the weather is exceptionally cold, since the impulse line will not be flowing in the same way as the water pipe. Since glycerin has a greater density and a lower freezing point, the glycerin will remain static inside the impulse line and protect the line from hazardous conditions.

The use of an isolating diaphragm negates the need for certain considerations of fill fluid density, piping layout, and the need to create an arrangement that holds the fill fluid in place within the impulse line. System pressure will be transferred across the diaphragm from the process fluid to the fill fluid, then to the pressure sensor. It is important to utilize fluids and piping arrangements that do not affect the accurate transference of the process pressure. Any impact related to the impulse line assembly must be determined, and appropriate calibration offset applied to the pressure sensor reading.

An essential design element of a filled impulse line without an isolating diaphragm is that the fill fluid must be compatible with the process fluid, meaning there can be no chemical reactivity between the two. Additionally, the two fluids should be incapable of mixing no matter how much of each fluid is involved in the combination. Even with isolating diaphragms employed, fluid harmony should still be considered because a diaphragm could potentially loose its seal. If such a break were to occur, the fluids used in filled impulse lines may contact the process fluid, with an impact that should be clearly understood through a careful evaluation.

Share your pressure measurement requirements and challenges with experienced application specialists, combining your own process knowledge and experience with their technical expertise to develop an effective solution.

Pressure Measurement Handbook From Yokogawa

Pressure Transmitter
Courtesy Yokogawa

The impact of pressure on industrial processes would be difficult to understate. Pressure is an element of process control that can affect performance and safety. Understanding pressure concepts and how to effectively measure pressure within a process are key to any operator's success.

Yokogawa, a globally recognized leader in process measurement and control, has made available a handbook on pressure that covers a range of useful topics. The content starts with the very basic concepts and moves quickly to practical subjects related to process measurement and control.

The handbook will prove useful to readers at all levels of expertise. Share your process measurement challenges with application specialists, combining your process knowledge with their product application expertise to develop effective solutions.

Pressure Measurement Handbook for Process Control from Classic Controls, Inc.

New Website For Classic Controls

Home page on Classic Controls new website

Classic Controls, distributor of industrial process measurement and control equipment and instruments throughout Florida, Georgia, Puerto Rico, and the Caribbean, has a new website that is live now. The new site provides simple and rapid access to Classic Controls' represented lines and products, as well as the company's social media outlets, all organized in an intuitive and useful fashion to save users time in their search for solutions.

Visit the new site and see the products and capabilities of Classic Controls.