Saturday, February 24, 2018

Understanding Explosion Proof Enclosures Used in Process Control

This is a short video that explains what an explosion-proof enclosure is, what defines it as “explosion-proof”, and the principle behind why its safe to use in explosive or combustible atmospheres.

“Explosion-proof" doesn't mean the enclosure can withstand the forces of an external explosion. It means that the enclosure is designed to cool any escaping hot gases (caused by an internal ignition) sufficiently enough as to prevent the ignition of combustible gases or dusts in the surrounding area.

Friday, February 16, 2018

Introduction to Industrial Control Systems

Industrial Control Systems Control systems are computer-based systems that are used by many infrastructures and industries to monitor and control sensitive processes and physical functions. Typically, control systems collect sensor measurements and operational data from the field, process and display this information, and relay control commands to local or remote equipment. In the electric power industry they can manage and control the transmission and delivery of electric power, for example, by opening and closing circuit breakers and setting thresholds for preventive shutdowns. Employing integrated control systems, the oil and gas industry can control the refining operations on a plant site as well as remotely monitor the pressure and flow of gas pipelines and control the flow and pathways of gas transmission. In water utilities, they can remotely monitor well levels and control the wells’ pumps; monitor flows, tank levels, or pressure in storage tanks; monitor water quality characteristics, such as pH, turbidity, and chlorine residual; and control the addition of chemicals. Control system functions vary from simple to complex; they can be used to simply monitor processes—for example, the environmental conditions in a small office building—or manage most activities in a municipal water system or even a nuclear power plant.

Industrial Control SystemsIn certain industries such as chemical and power generation, safety systems are typically implemented to mitigate a disastrous event if control and other systems fail. In addition, to guard against both physical attack and system failure, organizations may establish back-up control centers that include uninterruptible power supplies and backup generators.

There are two primary types of control systems. Distributed Control Systems (DCS) typically are Supervisory Control and Data Acquisition (SCADA) systems typically are used for large, geographically dispersed distribution operations. A utility company may use a DCS to generate power and a SCADA system to distribute it.

process instruments
Field devices and discreet controllers used in control systems
(Foxboro Schneider Electric).
A control system typically consists of a “master” or central supervisory control and monitoring station consisting of one or more human-machine interfaces where an operator can view status information about the remote sites and issue commands directly to the system. Typically, this station is located at a main site along with application servers and an engineering workstation that is used to configure and troubleshoot the other control system components. The supervisory control and monitoring station is typically connected to local controller stations through a hard- wired network or to remote controller stations through a communications network—which could be the Internet, a public switched telephone network, or a cable or wireless (e.g. radio, microwave, or Wi-Fi) network. Each controller station has a Remote Terminal Unit (RTU), a Programmable Logic Controller (PLC), DCS controller, or other controller that communicates with the supervisory control and monitoring station. The controller stations also include sensors and control equipment that connect directly with the working components of the infrastructure—for example, pipelines, water towers, and power lines. The sensor takes readings from the infrastructure equipment—such as water or pressure levels, electrical voltage or current—and sends a message to the controller. The controller may be programmed to determine a course of action and send a message to the control equipment instructing it what to do—for example, to turn off a valve or dispense a chemical. If the controller is not programmed to determine a course of action, the controller communicates with the supervisory control and monitoring station before sending a command back to the control equipment. The control system also can be programmed to issue alarms back to the operator when certain conditions are detected. Handheld devices, such as personal digital assistants, can be used to locally monitor controller stations. Experts report that technologies in controller stations are becoming more intelligent and automated and communicate with the supervisory central monitoring and control station less frequently, requiring less human intervention.

Swanson Flo can help you with control system questions or challenges. Reach them by calling 800-288-7926 or visiting

Tuesday, February 6, 2018

Foxboro Magnetic Flowmeter for Chemical and Process Industries

Based on Faraday’s law of induction, Foxboro magnetic meters are a reliable  ow measurement solution with a lower cost of ownership and maintenance, as well as  eld-proven stability to maximize the availability of  ow measurement.

With a wide range of liners and electrodes, the 9700A  owtube is ideal for the Chemical and Process industries. In combination with the IMT30A, IMT31A and IMT33A transmitters, Foxboro offers an innovative solution designed to meet the demands for all chemical applications such as:
  • Clean liquids
  • Mixing of chemicals
  • Demanding applications including corrosive, abrasive liquids • Rapid variation of the pH value
  • For slurries and pastes with high solids content
  • Drilling applications, mining slurries with large particles

See the embedded brochure below, or download your own PDF from this Swanson Flo link.