Selecting the Right Temperature, Pressure, or Differential Pressure Switch

Temperature, pressure, and differential pressure switches come in a wide variety of configurations
Courtesy Ashcroft

Industrial process control applications present dynamic and varied requirements for measuring, monitoring and control. Each point calls for specific evaluation of the information needed from the process point for use in monitoring process performance, or control to be applied at the process point to regulate an outcome. Sometimes, a continuous analog signal is needed to provide indication across a range of values. Other times, it is only necessary to have notification of, or take action when, a certain temperature or pressure related event occurs. In those cases, a simple and reliable device can adequately meet the project requirements.

Temperature, pressure, and differential pressure switches connect to a process and change their switch position when a setpoint condition is reached. The are simple to understand, easy to install, low in cost, and require little maintenance of attention. The switches are available in an extensive array of configurations, with options to fill out almost any application requirement.

Ashcroft, global supplier of temperature and pressure switches, has produced a simplified guide that enables a designer or specifier to quickly focus their search on the right product. It is provided below for your use. Alternately, you can always share your process measurement and control requirements and challenges with product application specialists, combining your own process knowledge with their product expertise to develop effective solutions.

Selection of Temperature, Pressure, and Differential Pressure Switches from MSJacobs-Cali

CSB Case Study of Industrial Plant Heat Exchanger Explosion

Two heat exchangers at chemical plant

Industrial accidents, whether minor or catastrophic, can serve as sources of learning when analyzed and studied. Operators, owners, and technicians involved with industrial chemical operations have a degree of moral, ethical, and legal responsibility to conduct work in a reasonably and predictably safe manner without endangering personnel, property, or the environment. Part of a diligent safety culture should include reviewing industrial accidents at other facilities. There is much to learn from these unfortunate events, even when they happen in an industry that may seem somewhat removed from our own.

The U.S. Chemical Safety Board, or CSB, is an independent federal agency that investigates industrial chemical accidents. Below, find one of their video reenactments and analysis of an explosion that occurred at a Louisiana chemical processing plant in 2013. A portion of the reenactment shows how a few seemingly innocuous oversights can combine with other unrecognized conditions that result in a major conflagration.

Check out the video and sharpen your sense of awareness for potential trouble spots in your own operation.

Improved Level Measurement Contributes to Reduced Heat Rate in Steam Production

Minimizing heat rate and emissions for steam plants

Steam production is a costly operation in any facility, but is of paramount importance in power generation plants. The bottom line of a combustion based power generation facility is sensitive to the cost of input fuel. Measures that can be taken to reduce fuel input for a unit of power output (called heat rate) can translate directly into profitability. An additional benefit of reducing heat rate is a commensurate reduction in emissions.

A major contributor to heat rate reduction is the recovery of heat from the process and transference of that heat into the boiler feedwater. A sizable feedwater preheater of the shell and tube type is used to recover the heat. Shell and tube heat exchanger efficiency can be maximized with accurate control of liquid level.

Magnetrol, globally recognized leader in level measurement technology, makes the case for using guided wave radar level measurement technology as the most advantageous means for this application. The video below describes the process and how the guided wave radar level transmitter can provide the best performance.

Magnetrol has an information kit devoted to heat rate reduction. Share your steam system and level measurement challenges with a product specialist, and ask how you can get the Heat Rate Reduction Kit. Combining your facility and process knowledge with the product application expertise of a specialist will result in effective solutions.

M.S. Jacobs & Associates - Equipment Engineers

Wastewater treatment is one of the many industrial sectors
served by M.S. Jacobs

M.S. Jacobs and Associates has been a leading manufacturer's representative and distributor of industrial instrumentation and controls since 1945. Expanding from its original focus on the steel industry, MS Jacobs services and supplies products in all major industrial markets, including power generation, chemical processing, pulp and paper, oil and gas production, water and wastewater treatment, and nuclear power generation.

The company's longevity and dedication to the industrial market has resulted in a broad offering of superior quality products for flow, level, pressure, and temperature measurement, as well as filtration products and valves. Everyone at MS Jacobs takes pride in the company's ability to solve tough applications and provide exceptional customer service with a team of trained outside sales engineers and inside customer service representatives.

MS Jacobs' Pittsburgh service center provides instrument calibration and repair for MSJ's complete line of products, as well as those of other manufacturers. The company carries factory authorization for repair of numerous manufacturers' industrial process instrumentation products. The service center also provides custom assembly of instruments and other gear to meet customer requirements. Completed assemblies are tested and certified prior to shipment.

Reach out to MS Jacobs & Associates for the products and services that move your process instrumentation and control projects toward a successful completion.

MS Jacobs Line Card & Product Offering from MSJacobs-Cali

Self-Regulating Heat Trace for Freeze Protection

Example of self-regulating heating cable
Courtesy BriskHeat

Freeze protection is probably the most obvious application range for heat trace tape and cable. The applications are vast in number throughout the geographic region where real winter comes every year. Pipes, valves, tanks, vessels, conveyors and other equipment are all vulnerable to excessively cold conditions. Properly configured heating cable, blankets, or other shapes can reduce the risk of freezing liquids and keep protected items at safe operating temperatures.

Though freeze protection heating equipment and materials are available in many shapes, forms, and materials, this article will focus on self-regulating heating cable.

There are two basic types of heating cable. 

Constant wattage cable provides continuous full output whenever energized. It's application requires some means of limiting the temperature of the heated object. This can be a thermostat, or some other temperature controller and sensor combination. This simple on/off control is effective in many cases. More sophisticated arrangements can be accomplished with heater power controllers and a closed loop control system. The objective is to apply only as much heat (and energy) as necessary to prevent freezing or other cold induced undesirable conditions.

Self-regulating cable is designed and fabricated in a manner that reduces the heat output of the cable as its temperature increases, providing a built-in means of limiting applied heat without the need for any other means of control. Properly selected and installed heat cable of the self-regulating type will apply only the heat energy needed to maintain the desired condition. No other devices are required.

There are many heating solutions available for freeze protection to suit any application. Share your process heating and freeze protection challenges with product application specialists, combining your process knowledge and experience with their product application expertise to develop effective solutions.

Application of Self Regulating Heat Trace in Wastewater Treatment Plant from MSJacobs-Cali

Hinge Restrained Expansion Joints for Process Piping

Cutaway view of hinge restrained expansion joint

Process piping of sufficient size or extent can require allowances be made for expansion of the piping material in the installed location. The design criteria will include factors that impact the expansion of the piping components, as well as the relationships between the piping and elements of their supporting structures. Expansion can produce substantial movement of pipe sections which must be accommodated by the supports and the piping itself.

One manufacturer, General Rubber Corp., provides a hinge restrained rubber expansion joint that is designed to allow angular rotation of a piping section within a single plane. The expansion joint isolates the movement of one pipe section from its adjacent connected section. The assembly is comprised of a pair of pin connected hinge plates attached to the expansion joint hardware. The company further describes the unit construction and function...

The hinge assembly must be designed for the internal pressure thrust forces of the system. They can be used in sets of two or three to absorb large lateral movements in a single plane. This optimally designed arrangement is an effective solution for absorbing large axial thermal movements from an adjacent pipe run. Its spool type body is constructed with full rubber flanges, a high-grade leak proof-tube, multiple layers of high-strength tire cord, high tensile steel reinforcement and a seamless cover. They are commonly used when the support structure or adjacent equipment have load limitations. The economic benefits of this arrangement include a smaller system footprint with far fewer anchors and guides.

The video included below provides an animated illustration of how the expansion joint functions. More information is available from product specialists, with whom you should share your process piping system challenges.

Hazardous Gas and Flame Detection

Carbon dioxide level detector
Courtesy Sierra Monitor Corp.

MS Jacobs handles the Sierra Monitor line of gas and flame detection devices for use in commercial and industrial facilities. SMC manufactures complete solutions for gas and flame detection, from the sensors to the monitoring and control stations. The systems approach includes sensor modules, controllers, and software working together to provide detection, alarm, analytics, and delivery of all necessary information across communications networks.

SMC employs a variety of technologies to provide application matched performance in their gas and flame detectors. The company innovates and leverages their IIoT (Industrial Internet of Things) expertise to bring operating efficiency and enhanced levels of protection to customer facilities. Systems are tailored to provide the level of protection appropriate for a facility or application, as well as a customized response.

The various sensor  modules are optimized for their intended application range, bringing accuracy and efficiency to hazardous gas and flame detection. Some of the benefits include:

• Low power requirements
• Rapid response
• Various filtering means to discriminate between noise and real hazards
• Multiple output options that include relays, analog, and digital communications
• Long calibration intervals for reduced maintenance
• Remote sensor configuration
• Self diagnostics
• Local display
• More

Share your gas and flame monitoring challenges with application specialists, combining your process and facility knowledge with their product application expertise to develop a comprehensive and effective solution.