Got a Boiler? Get This Reference For Your Maintenance Techs.

Drum Level Indication Guide

Industrial and commercial boilers, while commonplace in our infrastructure, are serious and potentially dangerous devices that require diligent attention in order to maintain safe operating conditions. Many modern elements of boiler design and the arrangement of their installation sites are responses to past catastrophic failures that we all wish to never recur.

Part of the diligence that keeps steam systems operating safely is periodic inspection of equipment and safety instrumentation. One manufacturer of water level indication instrumentation has compiled the latest ASME code requirements for drum level instrumentation with some additional best practices into a laminated, field hardened, booklet for use by mechanics, engineers, and other stakeholders in safe boiler operation.

Clark-Reliance Corporation, manufacturer of boiler water level instrumentation and controls, offers "Boiler Inspection Guidelines for Drum Level Instrumentation" free of charge to those interested in this aspect of boiler operation safety. Request a free copy below. Get it for your use and knowledge, or for the mechanics or contractors that maintain your boiler and steam system. The publication outlines the code requirements, provides some best practice recommendations, and provides illustrations of some correct and incorrect installation practices. It also presents different types of level indication device technologies and where each can be properly applied.

Get your free copy of the publication and put it to good use by requesting the "Clark-Reliance drum level inspection guide" at the link.

Handbook provides examples of code violations and corrections.

Severe Service Ball Valves Meet Toughest Application Challenges

Severe Service Ball Valve Section View
Courtesy Mogas Industries

Industrial process control, as a field of endeavor, can expose an engineer to instances where their design input can have very significant impact on the financial prospects of their employer, even the safety and well being of the public residing near company facilities. "Getting things right the first time" is much more than a motivating slogan on a poster tacked to the wall in the corridor outside the engineering department. It is what our society demands of engineers. Fortunately, there are engineers that embrace the role of making sure things go as planned. They work as process engineers and also as designers of the componentry and equipment used to implement complex and potentially dangerous processes.

I have written about the positive and potentially not so positive attributes of ball valves for industrial process control applications. In that recent blog article, I mentioned that ...

"There may be particular ball valve variants that overcome potential shortcomings listed in this article".

Ball valves designed for severe service are an example of a manufacturer specifically designing ball valves to not only overcome some potential shortcomings of the valve type, but to extend the performance ratings into areas that accommodate some of the most demanding applications in the process control field.

What constitutes severe service?

• Extreme temperatures
• High pressures
• Abrasive particulates
• Acidic products
• Heavy solids build up
• Critical plant safety
• Large pressure differentials
• Velocity control
• Noise control

Extended or enhanced features of severe service ball valves include:

• Floating or trunnion mounted ball design with straight through bore path that protects the sealing surfaces.
• Wide seat sealing surface with matched ball and seat sets that provide total sealing contact for reliable isolation. The greater sealing contact area withstands minor scratches and abrasions.
• Independent replaceable seats to minimize repair and maintenance costs.
• Pressure energized sealing, with seat springs that maintain a constant sealing contact between the ball and seats. Metal seats wipe the ball sealing surface clean during every operation.
• Blowout proof one piece oversized stem design meets stringent industrial safety standards and withstands maximum working pressures and extreme service torques.
• Dual-guided stem design employs pressure energized inner stem seals as a thrust bearing and lower stem guide. The valve stem bushing serves as the upper stem guide to eliminate lateral movement of the stem and prevent media migration and fugitive emissions.
• Greater body wall thickness, with forged body and end connections for longest service life.
• A heavy duty operator mounting flange, to provide structural support for the valve operator, is machined after attachment to assure precise stem alignment.

Application specific features, such as seat designs, live loaded packing, body gaskets, coatings, liners, purge ports, end connections, and special materials are also available to customize these severe service valves to meet extreme application requirements. The presentation below provides schematic and illustrated examples where severe service valves are applied and provides additional detail about the special features incorporated in the design of severe service ball valves. For all your control or isolation valve projects, whether in the conceptual, planning or implementation stage, consult a valve specialist. Merge your grasp of the process and its requirements with the product knowledge and application experience of a specialist and produce a solidly positive project outcome. 

Severe Service Control & Isolation Valves in the Refining Industry from CTi Controltech

Valve Actuator IQ Suffering? This Information Library Can Help.

IQ Series Electric Valve Actuator
Courtesy Rotork

For any component of your industrial process, there is a manufacturer that knows all about how to properly and safely apply, service, maintain, and repair it. The devices we employ to measure and control industrial processes and machines grow increasingly numerous and complex. While this provides operators with greater amounts of useful information, leading to safer and more efficient process operation, the burden on engineers and technicians tasked with coaxing maximum uptime and efficiency from the process grows. Never before has continuing education, even relearning of basic knowledge, been so important. One manufacturer has invested in helping customers and other industrial process control stakeholders keep their operation and maintenance knowledge current.

Rotork, a global manufacturer of industrial valve actuators, maintains extensive online information sources that are accessible to registered users. The instructional and educational assets include online course applications, videos, and other materials to familiarize the user with various aspects of Rotork actuators, their proper application, operation, and maintenance. The large library of "How to" videos provides clear instruction on the safe operation and application of the Rotork actuators, along with step-by-step instruction on how to perform the range of operations involved with obtaining the greatest benefit of ownership. Process engineers, operators, and technicians will all benefit from the assets, enabling them to interface with the products with the confidence that comes from knowledge.

Contact your Rotork distributor for instructions and assistance in gaining free access to the educational tools.

Innovative Magnetic Level Gauge Provides Accurate Indication Under Adverse Conditions

Magnetic Level Gauge on Tank
Courtesy Jerguson

We, as engineers, industrial process operators and stakeholders, recognize the necessity and value of a continuous stream of accurate and timely information about our processes. Our experience has also taught us that the environment and activities surrounding our installations can have a significant impact upon our ability to continually gather accurate process measurements. Some of our concerns include:

• Weather - An element whose impact cannot be understated....or easily predicted.
• Physical Contact - Equipment and measurement devices must be protected from damaging impact.
• Security - Vandalism, cyber invasion, and other external threats are possible

Our responsibility, as operators of machines and handlers of materials that can produce hazardous or life threatening conditions in the case of failure or error, is to foresee every reasonably probable event that could adversely impact the safe and proper operation of our industrial processes.

One manufacturer has developed an innovative solution to a potential problem in the application of magnetic level controls.

The short video below outlines the source of the potential failure and the way in which the product design change successfully overcomes a potentially adverse impact on process measurement. Invest less than three minutes of your time to watch the video and build your application knowledge by learning from the experience of others. Do not hesitate to contact a product application specialist for more detail, or to discuss your process measurement needs.

Rotork Skilmatic Valve Actuators Enhance Performance and Safety

Electro-Hydraulic Valve Actuator
Courtesy Rotork

Incorporating levels of performance and safety into industrial fluid handling systems presents ever increasing challenges to those designing, owning, and operating those systems. Rotork Fluid Systems developed the Skilmatic line of valve actuators to provide the positioning performance, operational safety, and data connectivity needed for best-in-class implementation of industrial process control valves.

The Skilmatic range of self-contained electro-hydraulic actuators combine the precision of hydraulic control, the simplicity of electrical operation, and the reliability of mechanical fail-safe action into a single integrated product. In addition to general purpose, flameproof, and modulating versions of the actuators, Rotork offers intelligent versions of the product that deliver improved control and monitoring functions:

• Datalogger recording of events, trends, alarms.
• Bluetooth connectivity for data download and upload between actuator and Rotork’s InSight2 software.
• Semi-automatic position limit calibration.
• Partial stroke operation.
• Improved position control for modulating operations.
• Valve flow characterization for modulating control with various valve attributes, such as equal %, linear, and more.
• Manual override detection.
• Alarm output relays with selectable function.
• Internal temperature sensor.

The actuators are available in a myriad of configurations to suit every application. A wide range of standard arrangements are offered, along with custom versions configurable to provide a specific solution demanded for a special application. A deeper profile and description of the product line, principals of operation, and operational benefits is available from a product specialist, who can also assist with selecting and configuring the right unit for your project or application.

Electric Boilers - When Are They the Best Choice as a Steam Source

Electric Boiler
Courtesy Williams & Davis Boilers

Commercial and industrial boiler applications are diverse, with more to be considered than fuel costs alone. There can be instances where other operational or procurement criteria can override fuel costs as a determining factor in boiler selection. Sometimes, an electric boiler may be the best overall choice for a project or application.

Electric boilers are comparatively simple devices. They will resemble their combustion heated cousins in practically all aspects related to the the handling of water and steam. Where they differ is the means of heating.

Electric boilers have bundles of electric heaters immersed in the water to be converted to steam. Electrical switching gear and controls that regulate the operation of the heaters in response to steam demand will likely be mounted integrally to the unit. What will be missing is all the hardware needed for fuel storage, delivery, regulation, and ignition, along with a host of other items needed for the presence and handling of a combustible fuel supply and removal of the products of fuel combustion.

Let's look at some points that may prove advantageous for an electric boiler installation.

Cutaway View of Electric Boiler
Courtesy Williams & Davis Boilers 

• Small steam requirements: Installations with highly localized or small scale requirements for steam may benefit from the lower complexity of an electric boiler installation.
• Intermittent operation: Electric boilers are very easy to start and stop.
• Shortened project timeline: The installation of an electric boiler generally does not have as many infrastructure requirements as those utilizing combustible fuels, allowing for reduced time between project inception and completion. 
• Reduced installation costs: No need for the provision or storage of combustible fuel and the associated operational and safety infrastructure. In some jurisdictions, it is permissible to locate an electric boiler in proximity to the steam consuming device, reducing costs for piping. 
• Reduced maintenance requirements: Electric boilers have almost no moving parts, no flue, no burners, no fuel system, and none of the hardware, maintenance, or regular inspections associated with combustion safety.
• Operation of electric boilers is comparatively quiet.

If your application can benefit from some of these potential advantages of electric boiler installation, an analysis of the longer term costs may be in order. The generally reduced energy cost of combustion based systems may, at some point, make them a better choice. With your steam production and demand requirements in hand, contact a boiler specialist that can provide both electric and combustion heated systems and chart out the tangible and intangible benefits of several options. The right choice will be revealed with a careful analysis.

When a Ball Valve is the Right Choice

Cutaway View of Industrial Ball Valve
Courtesy of Flowserve Atomac

Industrial fluid handling and process control rely on valves to regulate the pressure and control the flow rate and direction of a wide variety of liquids and gases. There can be highly sensitive or specialized performance requirements, along with additional needs for corrosion resistance and an ability to withstand extreme fluid or environmental temperatures. Selecting the proper valve can be a challenging and time consuming operation for a new or updated process. Taking an initial step of narrowing the field of potential candidates to those with basic operational and construction characteristics that will be advantageous to your process requirements will move you quickly toward an effective selection.

Industrial valves for flow control are often grouped and referred to by their closure mechanisms. Common types include ball, plug, butterfly, globe, and gate. Each type has attributes making it more suitable to certain applications. Start your selection process by choosing a valve type that will provide the type of service needed. Let’s look at ball valves.

Ball valves are named for the generally spherical shaped element encased in the valve body and placed directly in the fluid flow path. The ball has a hole, or port, through it’s center that allows fluid to pass when the port is aligned with the direction of flow. The stem, attached to the ball and extending to the exterior of the valve body, that can be rotated through a 90 degree arc manually, or utilizing a powered actuator. At one extreme of the arc, the port is perpendicular to the flow path and fluid flow is completely obstructed and shut off. Rotating the stem ninety degrees from the closed position will align the port with the flow direction in the fully open position.

What are some potential advantages of ball valves?

Interior of Ball Valve
Courtesy of  Mogas Industries

• Well suited for applications requiring either full flow or no flow.
• Quarter turn operation provides a rapid transition from open to closed position.
• Leak-proof service.
• Force required to drive the valve stem is comparatively moderate.
• No lubrication required and maintenance is minimal.
• Comparatively light weight and compact, reduced installation space and support requirements.
• When fully open, the port provides little resistance to flow with a straight through path.

What are some potentially concerning attributes?

• Residual amounts of the process fluid may be trapped in the port when the valve is closed, then released to the fluid stream when the valve is opened. Potential contamination impact should be considered.
• Ball valves are not well suited for throttling of the flow. Partially open ball valves expose seals and sealing surfaces to effects of the fluid velocity and potentially corrosive nature of the fluid. Additionally, the basic construction and operation of the ball and port generally do not provide variable flow control as well as some other valve types.
• Valve seals, most often elastomertic materials, may not be compatible with fluid characteristics. Consider temperature, corrosiveness, and other fluid characteristics for compatibility with the seal material.

These general points are intended to get you thinking about your valve application in a productive and efficient manner. There may be particular ball valve variants that overcome potential shortcomings listed in this article. Talk to a valve specialist about your application. Their recommendation, based upon high level product knowledge and experience with numerous applications, will be a valuable addition to your decision making.