Wednesday, May 29, 2019

What Are Pneumatic Actuators?

rack and pinion actuator
Internal view of rack and pinion actuator
(Flowserve Worcester)
Pneumatic valve actuators are used in extreme conditions in many industries such as oil and gas, chemical, water and wastewater, bulk storage, pulp & paper, and power generation. These devices are used in a multitude of valve control processes for regulation (or cessation) of flow, controlling pressure and adjusting level.  Due to their reliability and simplicity, pneumatic actuators are one of the most popular types of actuators used in industry today.

Pneumatic valve actuators work by conversion of air pressure into motion. The device applies a force of air to a diaphragm, rotary vane, or piston that is attached to the actuator shaft, which is then mechanically connected to the stem of the valve or damper. Depending on the type, pneumatic actuators produce either linear or rotary motion. 

ACTUATOR ACTION - SPRING RETURN OR DOUBLE ACTING

Spring Return — Pneumatic actuators with spring return design have air supplied from one side. The spring on the opposite side is responsible for the motion. With this design, air compression moves the opens or shuts the valves while the spring is responsible for the opposite motion. 

Double Acting  — Double acting actuators have air fed on both sides of a piston. The pressure on one side is higher as compared to the other that results in the required in movement. Air is used to open and close the valves.  

Diaphragm actuator
Diaphragm actuator
(Samson)
PNEUMATIC ACTUATOR DESIGNS

Diaphragm Actuators — Diaphragm actuators work by applying pressure to a thin membrane or diaphragm. 

Piston Actuators — Piston actuators apply compress air to a piston that is within a cylinder. Air is fed into a chamber that moves the piston in one direction. The piston moves in the opposite direction when air pressure is removed (spring assisted) or directed to the other side (double acting). 

Rack and Pinion — Rack and pinion actuators produce rotation by applying pressure to pistons with gears that turn a pinion gear. Rack and pinion actuators can be spring return or double acting. They are valued because of their compact size and versatility.

Scotch Yoke — A scotch-yoke actuator contains a piston, yoke, connecting shaft, and rotary pin.
Scotch yoke actuator
Scotch yoke actuator
(Samson)
They can be direct acting or spring return. They are capable of providing very high torque outputs and are generally used on larger valves. Scotch yoke actuators can be powered by air or process gas.

Rotary Vane —Vane actuators use a mechanical vane, connected to a shaft, that separates a circular shaped body in two "clamshell" halves. The vane moves in response to the differential pressure inside the actuator body, turning the shaft clockwise or counter-clockwise in response to the pressure differential. External springs units are available for spring return models.

BENEFITS OF PNEUMATIC ACTUATORS

The use of compressed air (typically found in all industrial facilities) as the power source is the prime advantage for the use of pneumatic actuators. Additionally, pneumatic actuators have an advantage in suitability for different environments and can be used in extremes temperatures. They are preferred over electrical actuators in explosive, flammable and other hazardous areas because they do not require electricity (a possible ignition source) to operate. They do not create electrical fields or electrical noise since there is no electrical motor. Pneumatic valve actuators are faster opening and closing compared to their electric counterparts. Finally, they are low cost, lightweight, durable, require little maintenance (depending on quality) and there are a myriad of positioning controls, speed controls, and communications devices available for tailoring the actuator to the application.

DRAWBACKS OF PNEUMATIC ACTUATORS

While compressed air is the main reason for using pneumatic actuators, it can also be considered a drawback. For instance, pneumatic actuators can perform poorly when the air supply source is located at a distance, resulting in lag and slow response. Another drawback of pneumatic actuators is the additional cost for the compressed air system due to the requirement of dust filters and moisture removing dryers. These are required to ensure clean air is fed into the system.

APPLYING PNEUMATIC ACTUATORS

There are many aspects to the proper, safe, and efficient application of pneumatic actuators to valves and dampers. Sizing the power output (torque) being paramount. All valves and dampers have unique torque requirements. You must consider a threshold force for opening (breakaway), as the valve continues to move to its open or closed position, and then for seating. Matching the actuators to the valve type, and operating conditions is critical. Published torque curves must be reviewed and understood. Too little torque and the vale will not respond. Too much torque increases cost and can damage the valve. Spring return adds to this complexity. Considering all this, it is strongly suggested you always discuss any valve actuation requirement with an experienced applications expert. They will ensure the proper, safe, and cost effective mating of pneumatic actuator to valve or damper.

Saturday, May 4, 2019

What Is IIOT? Understanding Industrial IoT and the Technology Behind It

What Is IIOT
IoT or the internet of things needs no introduction. However, you may want to familiarize yourself with its offshoots such as the Industrial IoT, better known as IIoT. The simplest way to define IIoT would be the implementation of IoT capabilities in an industrial or manufacturing setting.

An amalgamation of various technologies such as big data, machine learning, automation, and sensor data, industrial IoT enables a connected enterprise by combing the information and operational department of the industry. Let’s take a more detailed look at IIoT and the technology behind it.

Understanding IoT

A sector that is rapidly progressing and accounts for a major share in the global IoT spending, IIoT provides manufacturers and industrialists with a significant opportunity to not only monitor but also automate many complex manufacturing/industrial processes. IIoT, a network of connected devices, enables systems to collect, track, disseminate, and analyze valuable new insights.

With these insights, industrial companies can make smarter, faster business decisions. By changing how industries work, IIoT is transforming them. Additionally, businesses are getting desired outcomes by integrating IIoT with other technological solutions. This includes providing production data in real time to unveil additional plant capacity, stopping cyber-attacks through increased visibility or control over the industrial control systems, and allowing identification of corrosion within a refinery pipe through predictive analytics.

IIoT is driving incredible levels of efficiency, productivity, and performance by combining technology, industrial big data analytics, cyber security, and machine-to-machine (M2M) communication. And, this has helped bring transformative operational and financial benefits to companies in the healthcare, aviation, manufacturing, oil & gas and power & energy sectors.

The Future of IIOT

It is predicted that the industrial internet could be worth over $200 billion by 2030. This is the reasons many companies have invested heavily in the industrial internet. Example of this is the Industrial Internet Consortium—an association founded companies to accelerate the development, adoption, and widespread use of interconnected people, machines and devices and intelligent analytics.

SIEMENS is helping drive the industrial transformation by leveraging the potential of the industrial internet. The company predicts that in the future, IIoT will account for a major share of the global economy and will impact both energy production and energy consumption. Today, industries are making all sorts of efforts to modernize systems and equipment to meet new regulations, keep up with increasing speed and volatility of the market and deal with disruptive technologies.

Significant improvements to efficiency, safety, and profitability have been experienced by businesses that have embraced IIoT and this trend is expected to continue in the future as IoT technologies are more widely adopted.

If you want to learn more about IIoT, contact Ives Equipment. The can be reached by visiting https://ivesequipment.com or by calling (877) 768-1600.