Improved Safety and Performance with Direct Coupled Gas Valve/Actuator Assemblies

Historically linkages are more common than direct coupled actuators. Control actuators were usually foot-mounted. A foot-mounted actuator has the mounting surface on the bottom and the drive shaft coming out the side. This arrangement invites linkage-type control. An example is a four-bar linkage. If any of these bar lengths are changed, it will affect the range and characteristics of the control valve. There are usually six security points in this configuration: actuator to crank arm, crank arm to swivel head, swivel head to linkage rod, and then double all of those for the valve side.

The actuator secured to the valve is critical to safe operation. The actuator becoming disengaged from the control valve is a significant safety concern. There is confidence in the crank arms' security and is considered a positive connection. The swivel heads are less secure. Typically the swivel head is clamped or presses a set screw into the linkage rod. Under conditions of vibration or varied temperature causing expansion and contraction, these connections come loose.  Because of this hazard with linkage, you'll occasionally see a position switch connected directly to the valve to verify the valve position.

Because the connections of a linkage are not rigid, there is a problem with hysteresis. The least rigid connections are the swivel connections. The actuator will push on the swivel head when driving open and pull on the swivel head when driving closed. There will be two different valve positions based on the direction hysteresis is created for a given control signal. Why is this important? Hysteresis hurts emissions efficiency and temperature control.

More recent control actuator designs are face-mounted. These newer designs make the mounting surface and the drive shaft on the same plane with the mounting face actuator shaft and valve shaft in line. Direct coupling the actuator to the valve is an improved design. 

For direct-coupled control, the stroke of the actuator equals the stroke of the valve. To adjust the stroke of the actuator, change the cams located under the cover to limit the stroke. The concept of cam adjustments in the actuator is commonplace for a direct-coupled arrangement.

There are just two secure connection points with direct-coupled: actuator to coupling and coupling to the valve. When done correctly, both of these points are positive connections. The machining of the actuator side of the coupling is commonly an irregular shape that doesn't allow the actuator shaft to rotate inside the coupling. On the valve side, a pin bolt goes through the coupling and the valve shaft. You can be more confident in a secure connection with a direct-coupled arrangement.

The inline connection of the actuator driveshaft and the valve shaft with a positively connected coupling eliminates linkage hysteresis. The coupling is a rigid piece that directly transfers the actuator movement to the valve movement, providing precise control which assists emissions requirements, optimizes efficiency, and facilitates high-performance temperature control.

Combustion Technology, LLC

Top 5 Gas Flow Meter Selection Criteria

Top 5 Gas Flow Meter Selection Criteria

The first and most important feature is that the flow meter is simple to set up and operate

Nobody enjoys complexities, and your facilities manager is no exception. Choose a simple flow meter to install, requiring little maintenance and not requiring any additional calculations. Make that the flow meter can connect with your DCS, PLC, or control system without difficulty. Knowing that the flow meter has the appropriate certifications for usage in dangerous regions is reassuring and a requirement! 

Flow meter precision is the second most important feature

Who knows what's going on behind the scenes in the pipes? As a result, you'll need a measurement instrument to correctly measure the flow in the pipes and provide you with a window into your process. Have high expectations for the process's correctness across the whole spectrum of operation, whether at high or low flow rates. 

Flow meter field flexibility is the third key feature

Flow meters with limited flexibility that require a return authorization to the manufacturer's factory for modification or recalibration are causing you downtime. Select a full-featured flow technology that allows the user to make adjustments or confirm accuracy in the field. These flow meters will keep you in control of your process and help you prevent downtime. 

Flow meter cost-effectiveness is the fourth key feature

Do your homework and acquire several quotations. Some technologies promise the moon and stars, but the price tag may be prohibitive. 

Flow meter reliability is the fifth key feature

Choose a flow meter that can accurately measure flow over time with minimal effort. The bottom line is that you want to be able to rely on the readings from your flow meter without needing to perform routine maintenance or recalibrations.

Selas Heat Technology Company Combustion Technology and Heating Product Catalog

Selas Heat Technology Company Combustion  Product Catalog


Selas industrial burners incorporate innovative combustion technology to ensure maximum performance and process efficiency. Selas remains the best choice for value, reliability, and performance with a wide variety of reliable burners and complete industrial combustion systems.

Selas products are used worldwide in numerous industries where heating products are critical to manufacturing goods. You will find Selas burners in automotive, food, petrochemical, metal, paper, forest products, aggregate, glass, and plastics manufacturing.

These industries require reliable burners for applications such as preheating, heat treating, annealing and tempering, melting, surface coating and modification, brazing, drying, finishing, baking and searing, and many more.

Combustion Technology, LLC

Hydrogen Ready Flame Scanners

Hydrogen Ready Flame Scanners

With the global energy market's increasing need for hydrogen (H2), proper flame detection and discrimination are crucial. Although ultraviolet detection is commonly utilized for H2 flame detection, it is only a tiny part of accurate detection. 

H2 is frequently used in conjunction with variable ratios of natural gas or other gasses to produce fluctuating flame characteristics. The wavelength of a typical H2 flame ranges from 220nm to 600nm, most of the time being in the 300nm range. Although this is outside the standard detection range of Gieger-Muller tube technology, contemporary solid-state sensors are more than competent. The flame flicker frequency changes as the H2 / gas ratio changes, implying that proper detection and discrimination require flame scanner technology to address these shifting flame profiles.

Fireye's InSight® scanners have shown to be effective in various H2 and H2 / gas mixture applications. While different flame scanners can detect the UV signal, not all of them have the many frequency settings needed to detect and differentiate. The InSight® range from Fireye features 21 adjustable frequency ranges and the option to keep four alternative sets for multiple fuel variations. These memory values can be changed during detection using two-wire communication. Fireye's InSight® series is available in IR or UV or in a dual UV & IR configuration, allowing you to add IR detection to the flame discriminating profile if necessary. All Fireye InSight® scanners are now available in ATEX and IECEx hazardous environment versions.

Fireye's InSight® Features

  • Infrared, ultraviolet or both 
  • 21 Frequency ranges
  • State of the art algorithms • A TEX & IECEx options
  • Global certifications 
  • SIL 3 certified
To discuss your flame detection / scanning application in the Pacific Northwest, contact Combustion Technology. Call 800-327-1831 or visit

Eurotherm EPC3000 Suggested Replacement for Obsolete Series 2000

EPC3000 Suggested Replacement for Obsolete Series 2000

The Eurotherm 2200 and 2400 controllers have been two of Eurotherm's longest-running and best-selling control products for the past 25 years. They have proven to be highly adaptable and dependable in a wide range of applications. Many things have changed since the 1990s, however, including considerable breakthroughs in microelectronics technology. Resultingly, Eurotherm incorporated these innovations into new and improved products. 

Consequently, Eurotherm chose to phase out the 2200 and 2400 series controllers on January 31, 2021, with repair and servicing available until 2025

Eurotherm suggests the EPC3000 series of programmable controllers as a substitute for the 2000 Series. They provide the same capabilities you've come to expect, as well as significant enhancements to assist meet today's needs. They also have wiring that is quite similar to the 2200 and 2400 series controllers. Additionally, they come in the precise three DIN sizes. 

Installing the controller into existing panels is painless and straightforward. Furthermore, the EPC3000 series was created with cybersecurity in mind and has been certified to exceed the rigorous standards of Achilles Communications Robustness Testing Level 1. You'll also get superior precision control, excellent thermal stability, and noise rejection. The EPC3000 is also more user-friendly, with a graphical wiring environment to aid in creating applications. Users can choose which function blocks to employ in their application and then connect them with "soft wiring" and includes a graphical setup. Ethernet connections are available via a standard RJ45 connector, allowing for quick access to process and diagnostic data and interface to an external PLC or a plant SCADA. 

The EPC3000 programmable controller provides outstanding value and includes numerous functions that are generally found only in high-end control packages. Whatever your process, the EPC3000 series may assist you in achieving the necessary stability, accuracy, and repeatability.

For more information in the Pacific Northwest, contact Combustion Technology. Call them at 800-327-1831 or visit their website at

The Siemens Combustion Controls SQM4 Synchro Modulating Actuator

The SQM40/SQM41 actuators are suited for driving oil pressure controller, butterfly valves, dampers or for use on other applications that require rotary motion.

The actuators are used primarily for load-dependent control of the flow of gas, oil and combustion air in connection with modulating 3-position controllers or continuous controllers (4-20 mA) and/or directly by burner controls.

The Siemens SQM4 series actuator is great for modulating air and fuel valves. it can also be mounted to a linkage for multiple control points. the resolution on this on this actuator is over 100 steps. this resolution is three times the leading competitor. this resolution is helpful to hone in on the desired set point with precision, rather than hunting or oscillating. this actuator comes in three torque settings: 45 inch pounds; 90 inch pounds; or 160 inch pounds. this actuator is NEMA 4. there is a gasket around the cover and the shaft is sealed to make it entirely NEMA 4. high fire and low fire conditions are simply set by turning these cams. 

The SCC SQM4 actuator has low voltage terminals and high voltage terminals. the low voltage is helpful for analog signals such as 4-20 mA, 0-135 ohm, and 2-10 volt DC. the high voltage terminals are for your line voltages for the actuator to modulate according to the analog signal voltage. 

The SQM4 series actuator is in stock for a common lead time of one to two days. this actuator can be direct coupled to a control valve for air or fuel control, or we also with couplings, crank arms and brackets to mount the actuator for your needs. 

Areas of application are oil and gas burners of medium to higher capacity as well as thermal process plants.

For more information in the Pacific Northwest, contact Combustion Technology. Call them at 800-327-1831 or visit their website at