Wednesday, January 18, 2017

Mountain States Engineering and Controls Expands Product Offering

duplex condensate return pump with receiver tank and sight glass
Duplex condensate return pump
Courtesy Sterling Sterlco
Mountain States Engineering and Controls has added the Sterling Sterlco line of condensate pump, boiler feed pump, and temperature control valve products to round out its comprehensive offering of instruments and equipment for steam systems and process cooling.

The Sterlco condensate pumps are available in simplex or duplex configurations, with pump and receiver capacity ratings to accommodate a broad range of industrial and commercial applications. Option selections round out the flexible product specification.

Boiler feed pump units from Sterlco provide a similar extensive range of receiver and pump capacities, along with options to meet application specific requirements.

The Sterlco self powered modulating temperature control valves are available in eight sizes and provide regulation of coolant flow to a machine or process. Their simple design provides rugged temperature actuated performance in a wide array of cooling applications.

There is more to learn about Sterling Sterlco condensate pumps, temperature control valves, and boiler feed pumps. For the latest product information, or to work on a solution to your steam or cooling system challenges, reach out to an application expert and combine your facilities and process knowledge with their product application expertise to develop effective solutions.



Monday, January 9, 2017

Summary of Technologies Used For Continuous Liquid Level Measurement in Industrial Process Control

differential pressure transmitter with purge control for downpipe measurement
Differential pressure liquid level transmitter with
integrated downpipe purge control (bubbler method)
Courtesy King-Gage
Automated liquid processing operations in many fields have requirements for accurate and reliable level measurement. The variety of media and application criteria demand continuous improvement in the technology, while still retaining niches for older style units utilizing methods that, through their years of reliable service, inspire confidence in operators.

Here is a synopsis of the available technologies for instruments providing continuous liquid level measurement. All are generally available in the form of transmitters with 4-20 mA output signals, and most are provided with additional outputs and communications. What is notably not covered here are level switches or level gauges that do not deliver a continuous output signal corresponding to liquid level.

Whether considering a new installation or upgrading an existing one, it can be a good exercise to review several technologies as possible candidates for a project. None of the technologies would likely be considered the best choice for all applications. Evaluating and selecting the best fit for a project can be facilitated by reaching out to a product application specialist, sharing your applications challenges and combining your process knowledge with their product expertise to develop an effective solution.

Displacer – A displacer is essentially a float and a spring that are characterized for a particular liquid and range of surface level movement. The displacer moves in response to liquid level, changing the location of a core connected to the displacer by a stem. The core is within a linear variable differential transformer. The electrical output of the transformer changes as the core moves.

Guided Wave Radar – A radar based technology that uses a waveguide extending into the liquid. The radar signal travels through the waveguide, basically a tube. The liquid surface level creates a dielectric condition that generates a reflection. Calculations and processing of the emitted and returned signals provide a measure of distance to the liquid surface. No moving parts.

Magnetostrictive – A method employing measurement of the transit time of an electric pulse along a wire extending down an enclosed tube oriented vertically in the media. A magnetic float on the exterior of the tube moves with the liquid surface. The float’s magnetic field produces the return signal to the sensor. Processing the time from emission to return provides a measure of distance to the liquid surface.

Pulse Burst Radar - A radar based technology employing emissions in precisely timed bursts. The emission is reflectex from the liquid surface and transit time from emission to return is used to determine distance to media surface.  Not adversely impacted by changes in media conductivity, density, pressure, temperature. No moving parts.

Frequency Modulated Continuous Wave Radar – Another radar based technology that employs a radar signal that sweeps linearly across a range of frequencies. Signal processing determines distance to media surface.  Not adversely impacted by changes in media conductivity, density, pressure, temperature. No moving parts.

RF Capacitance - As media rises and falls in the tank, the amount of capacitance developed between the sensing probe and the ground reference (usually the side metal sidewall) also rises and falls. This change in capacitance is converted into a proportional 4-20 mA output signal. Requires contact between the media and the sensor, as well as a good ground reference. No moving parts.

Ultrasonic Non-Contact – Ultrasonic emission from above the liquid is reflected off the surface. The transit time between emission and return are used to calculate the distance to the liquid surface. No contact with media and no moving parts.

Differential Pressure – Pressure sensor at the bottom of a vessel measures the pressure developed by the height of the liquid in the tank. No moving parts. A variation of this method is often called a bubbler, which essentially measures hydrostatic pressure exerted on  the gas in a tube extending into the contained liquid. It has the advantage of avoiding contact between the measuring instrument parts, with the exception of the dip tube, and the subject liquid.

Laser - Probably one of the latest arrivals on the liquid level measurement scene, laser emission and return detection is used with time interval measuring to accurately determine the distance from the sensor source to the liquid surface.

Load Cell - A load cell or strain gauge can be incorporated into the support structure of the liquid containing vessel. Changes in the liquid level in the vessel are detected as distortions to the structure and converted, using tank geometry and specific gravity of the liquid.

All of these technologies have their own set of attributes which may make them more suitable to a particular range of applications. Consulting with a product specialist will help determine which technologies are the best fit for your application.

Monday, January 2, 2017

Steam Trap Maintenance Made Easier With Pipeline Connector

steam trap isolation valve set
PC4000 Pipeline Connector
Courtesy Spirax Sarco
Steam is a common source of heat or power throughout industrial and commercial installations. Most steam systems operate as a closed system, with return of condensate to maximize energy efficiency and gain other operational benefits. Steam traps are the workhorse of many condensate return systems, routing condensate back to the boiler and non-condensible gases out of the system, all without a major loss of steam.

Steam traps are points of high maintenance in the steam system. They are also an integral part of the system, meaning they are under pressure. Steam trap maintenance requires isolating the trap from the system, venting the pressure within the isolated section, and removing liquid that may be contained in the trap.

Spirax Sarco, globally recognized leader in steam system componentry and controls, provides a single unit solution for steam trap maintenance isolation. The PC4000 pipeline connector series (in the company's own words)...
"...are a complete 'Trap valve station solution' developed for use with two bolt universal swivel connector steam traps.
As the unit has been designed with two integral piston stop valves, it is possible to isolate both upstream and downstream of the universal trap connection and through the use of the fitted depressurization valves, possible to depressurize, test and drain the pipeline. The trap depressurization port also incorporates a maintainable 40 mesh stainless steel strainer screen to provide trap protection from system dirt and debris, which can be cleared through the use of the line pressure."
 A detailed data sheet is provided below for further review. Share your steam system challenges of all types with specialists, combining your facility and process knowledge with their product application expertise to develop effective solutions.


Wednesday, December 28, 2016

Keep Industrial Control System Cybersecurity Top of Mind

depiction of industrial data around the world cybersecurity
Industrial control system cyber security is a 24/7 operation 
Cybersecurity risks should be a concern to any business with an internet connection or data port. Smaller operators may feel their limited size and notoriety renders them generally immune to invasion. This is a falsehood. Every control system should be considered as a potential target. That said, paranoia and fear should not be your primary decision drivers. Cybersecurity is accomplished through awareness, diligence, and collaboration.

Even if you consider yourself a small and insignificant operator, it is useful to begin, then maintain, a connection to the conduits for industrial control system cybersecurity information. Develop your awareness of the potential for intrusion into your control system. Start to become knowledgeable about how cyber threats can impact your operation, how cyber intruders gain access. As you build your knowledge, it is likely you will find ways to improve your level of security without major change or expense.

The U.S. Department of Homeland Security houses the watchdog organizations for industrial control system cybersecurity. There is a group within the department that is dedicated solely to industrial control systems. The Industrial Control Systems Cyber Emergency Response Team, better known as ICS-CERT, works to reduce cyber intrusion risks for industrial control systems. The link for ICS-CERT should be your first stop when delving into industrial cybersecurity. The site provides links to many other resources and activities, all directly related to cybersecurity. You can sign up for newsletters, even receive alerts when new threats are uncovered.

Your steady progress of knowledge building will better prepare your organization for the cybersecurity challenges of the current environment, as well as those that will emerge in the future. A fact sheet from the National Cybersecurity and Communication Integration Center, providing some useful information on their functions and activities, is included below.

Any concerns you may have about the potential vulnerabilities of instruments or equipment currently in place should be shared with vendors as part of the evaluation of your current systems.


Tuesday, December 20, 2016

Power Generation Conversion From Coal To Gas - Impact on Valves

industrial gas turbine power generation
Gas Turbine
The combination of historically low gas prices and pressure from more stringent emission requirements for combustion operations has led to a wave of plant conversions from coal to gas as the fuel for power generating equipment. Conversions, as opposed to completely new facilities, pose a challenge regarding how much of the existing system can be used as part of the converted system. One aspect of that challenge is the valves on the existing system.

Crane ChemPharma & Energy, a globally recognized manufacturer of industrial valves for a wide range of applications, authored a white paper covering the subject of valve usage and replacement in power generation facilities converting from coal to gas. The paper provides a useful overview of the current state of power generating facilities with respect to regulation and the anticipated supply and cost of gas in the future.

The application and suitability of existing and new valves at various function points throughout the power generation system is outlined and explained. The paper does a good job of reducing the complicated issue into a few pages of direct understandable explanation.

The paper from Crane ChemPharma & Energy is included below. Share your industrial valve challenges with product application specialists, combining your own process expertise with their product knowledge to develop effective solutions.


Tuesday, December 13, 2016

Specially Designed Heat Exchangers Deliver Hot Water on Demand

plate heat exchanger steam to water Spirax Sarco
Plate heat exchanger for producing hot water from steam
Courtesy Spirax Sarco
Hot water is readily available on demand from your steam system with the application of a properly configured heat exchanger. The installation of a well designed steam to water heat exchanger can deliver large or small demand volumes of hot water efficiently and with little need for maintenance or attention.

Spirax Sarco, globally recognized leader in steam and condensate system solutions, provides complete pre-engineered heat exchanger packages for adding hot water production to a steam system. The company combines their renowned control components with a plate or shell and tube heat exchanger, all performance matched to provide optimum performance in a single package.

  • Compact design requires minimum footprint.
  • Control valves specifically designed for steam service deliver efficient operation and long service life with minimal maintenance.
  • Condensate removal system eliminates backup of condensate in steam space for maximized efficiency.
  • A single source for the entire unit assures a coordinated installation.
  • Low maintenance requirements.
  • All piping connections on one side for easy installation.
  • Hot water on demand reduces or eliminates the need to store hot water.
There is more to learn. Additional detail is provided in the document included below. Reach out to a steam system specialist with your questions, requirements, and steam system challenges. Combine your facility and process knowledge with their product application expertise to develop effective solutions.

Tuesday, December 6, 2016

Pressure Regulating Valves

industrial pressure regulator valve for steam brass
PIlot operated pressure regulator
intended for use in a steam system
Courtesy Pentair - Cash Valve
Many processes and equipment employ pressure regulating valves, the function of which is to maintain a desired outlet fluid pressure under varying conditions of supply pressure or outlet flow.

There are many pressure regulating valve variants, specifically designed to address a range of process conditions or offset a performance characteristic deemed undesirable in another design. Each variant has a suitable place in the range of possible applications, with cost, size, and complexity primary differences among the different offerings.

In its simplest form, a pressure regulating valve (PRV) consists of a flow restricting element, a measuring element, and a setpoint element. Outlet pressure applies force to the measuring element, often a diaphragm. As the outlet pressure increases, the diaphragm will move the flow restricting element toward the closed position, reducing the flow from the inlet. The restricting element is commonly a plug, disk, or some other recognizable valve trim arrangement. The setpoint element, likely a spring, provides a counterbalancing force on the diaphragm. When the force applied to the diaphragm by the outlet pressure reaches equilibrium with the counterbalancing force applied by the spring, movement of the restricting element stops. In this way, outlet pressure is controlled without the need for electric power, sensors, transmitters, or even a process controller. The entire assembly is self-contained and requires little attention.

Selecting a PRV for an application requires coordinated consideration of process performance range, desired conditions, and valve attributes to produce a selection that will provide the desired service. A valve improperly selected for an application may perform poorly. Some of the items to be considered include:
  • PRV Type
  • Body size
  • Construction
  • Pressure Ratings
  • Maximum Flow Rate
  • Outlet Pressure Range
  • Accuracy
  • Inlet Pressure
  • Orifice Diameter
  • Response Speed
  • Turn-Down Ratio
A PRV is not a safety device, so independent means must be provided to protect the system from excessive pressure. Product specialists are a good source of help in selecting a properly sized and configured valve for an application. Share your fluid process control challenges with a product application specialist, combining your process knowledge with their product application expertise to develop effective solutions.