What type of flow measuring device should I use? This is a recurring question. The choice is bounded by customer needs, product variables and different technologies available on the market today. It’s important to find a vendor with extensive knowledge in flow technology to guide you in your purchase. Selecting the wrong flow measuring instrument can result in inaccurate data and increased the cost from maintenance/replacements and upgrades. This blog focuses on two specific types of measuring devices: Rotameters (a variable area flow meter) and Thermal Mass Flow devices. We will outline how both devices work and highlight important specifications to look for when purchasing. This information will help guide Original Equipment Manufacturers (OEMs) and instrument manufacturers in selecting the right device when challenged with measuring gas flow in a range of industries from life science markets to industrial manufacturing.
Rotameters are widely used in a variable area flow meter due to low cost, simple installation, versatility, low-pressure drop, wide rangeability, and visual output. This device measures volumetric flow rate and is the best choice for measuring and controlling the gas volumetric flow under actual process conditions. A rotameter uses the variable area principle, which uses a very simple design, consisting of a tapered glass tube. In the tube is a weighted “float” made of a corrosion resistant material (sapphire, glass, stainless steel, carboloy™ or tantalum), that rises in the tapered tube with the increasing flow until the force from the fluid velocity matches the weight of the float. Because the float position relies on gravity, the rotameter must be vertically mounted. Most manufacturers offer rotameters with a glass tube in a metal housing in varying sizes. The rotameter can be the solution for many applications with a simple design, low cost, easy installation, optional manual controls, visual outputs and no required external power. The rotameter is less accurate when temperature and pressure changes occur. For many applications when high accuracy and high-pressure capabilities aren’t necessary and low cost is a priority, this device is a good choice. Mass flow devices are a more advanced technology but fundamentally both concepts are easy to understand.
Above is a diagram of a thermal mass flow system, one of the more popular mass flow systems. At a no-flow condition, the heat distribution along the sensor tube is balanced. With flow, the temperature profile (heat distribution) moves downstream as the upstream sensor is cooled, the gas carries heat from the upstream sensor (T1) towards the downstream sensor (T2). Only a small amount of the total gas flow is diverted through the sensor; the sensor is a stainless-steel tube wrapped in two heating sensors. Measurements are taken at both heat sensors, (T1) and (T2) (see diagram). The temperature difference between the two points will be zero when no flow is measured. As flow increases, the temperature profile shifts down the sensor tube, the gas molecules passing the first heated sensor (T1) will carry the heat away from the upstream sensor towards the downstream sensor (T2). The increased flow will result in a greater temperature differential as the center of the heat distribution moves downstream. These distinct heat profiles are measured as temperatures at the sensors. The magnitude of the shift is proportional to the mass flow within the sensor. In a mass flow controller, the customer’s flow requirement (setpoint) is electronically input into the digital controller (as either an analog or digital signal). The processor compares the customer’s digitized setpoint with the meter’s digital output and controls the proportional valve, to adjust flow to match meter output with the customer’s setpoint as quickly as possible. Mass flow measuring devices offer exceptional accuracy, high-pressure rating, automatic controls and electronic output — but these features mean an increase in cost. The initial investment can be justified if the integration into electronic systems, accuracy and durability mean cost savings in the future that outweigh the present cost.
Volumetric flow vs. mass flow
When comparing volumetric flow rate or mass flow rate, you need to know how accurate the measurement needs to be. The mass flow is best when accuracy is needed with a high-pressure rating. Volumetric flow is best when measuring the volumetric flow of the gas and high accuracy isn’t necessary. Compared to volumetric flow, mass flow shows virtually zero fluctuation with pressure and temperature. The cost between the two technologies is significant. However, new products, like Parker’s X-Flow Mass flow controller, are offering mass flow technology at a more economical price that is comparable to the higher end rotameter. Again, the initial investment, now less with Parker's X-Flow, can be justified if the integration into electronic systems, accuracy and durability mean cost savings in the future that outweigh the present cost.
Thermal mass flow devices
The thermal mass flow controller and thermal mass flow meter have become the leaders in flow accuracy and repeatability. Now, with products like Parker’s X-Flow, a more economical, compact, flexible and easy to use thermal mass flow instrument is available. Parker’s X-Flow offers a compact design, made of non-corrosive, chemically inert, chemically clean stainless steel and improves productivity and reduces costs in many analytical, industrial and OEM applications. The thermal mass flow controllers can monitor and automatically control flow while integrating into electronic systems. The results are accurate, repeatable, fast and reliable. In using the bypass technology, the series has a laminar flow element and turbulence filter, allowing for Parker to easily tune to a customer’s requirement and rapidly produce a specific flow range and maintain an accurate measurement.
Talking to experts is the best way to know what type of flow measuring device is best for you. Make sure the supplier has a history with volumetric and mass flow science to select the right product for your needs. Becoming an expert in these fields takes many years to develop and experienced engineers to design and produce.
Our applications engineering team is always available to provide recommendations and customize equipment to customer specifications. With over 30 years in both volumetric and mass flow technology, we have the knowledge to answer any questions. To speak with an engineer, call 603-595-1500.
This article was contributed by David P Sheffield, product engineer, Parker Precision Fluidics. David has been a mechanical engineer for almost 30 years and has 10 years of experience in mass flow and mechanical flow measurement technology.
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7 May 2019
Products used in the rigorous oil and gas industry must be resilient and of high quality to properly support these complex operations. Hoses and connections need to be safe, versatile and efficient. Rubber hose has its limitations when used in harsh environments. One of the issues is inner tube blistering. The blisters are caused by fluid over time permeating into the rubber core tube. When the pressure is released quickly, the fluid tries to escape quickly and damages the rubber core tube causing blisters that in turn cause leak paths in the core tube.
Parker has developed a high pressure hose specifically for subsea applications. The core tube is made of nylon which is time and field proven to work in subsea applications, and it is chemically compatible with subsea control fluids.
The flexible alternative to 1-1/2” I.D.
The Polyflex 2340N-24 Hose is specifically designed for subsea applications in the oil and gas market. It is a flexible hose that meets API 17E and ABS requirements. The seamless, extruded Polyamide core tube has a wide range of media compatibility, making it suitable for blow out preventer (BOP) equipment and many other offshore drilling applications. The high tensile steel reinforcement provides a full 5000 psi working pressure at 4:1 design factor. These features, combined with the sea-water resistant polyurethane jacket, offer a hose solution that withstands the rigors of the oil and gas industry and exceeds industry standard requirements. It is also available in long, continuous lengths. This is important because it reduces connection points, which reduces leak points, reduces set up time and allows for smoother routing of the assembly. Fewer connection points mean better flow.
The 2340N hose serves multiple applications in the oil and gas industry, such as BOP stack, acidizing, well stimulation, cementing and land or subsea based hydraulic systems. For more detailed information please reference the product data sheet for 2340N-24 Polyflex High Pressure Hydraulic Hose for the oil and gas market.
Visit us at OTC
Join Parker at booth 3639 during OTC May 6 – 9, 2019 at NRG Park, Houston, Texas to learn about our precision-engineered solutions to for the offshore market. We offer solutions to control your systems in deeper waters, at higher temperatures and pressures, and in the harshest environments with industry-leading efficiency and reliability.
Article contributed to by Will Solano, account manager, Global Sales Force, Parker Hannifin Corporation.
10 Apr 2019
Check valves are unseen and undervalued. These valves are found in just about every mobile and industrial hydraulic system on the planet. Simply put, if there’s a pump, most likely you will find a check valve. Check valves keep the fluids flowing in the desired direction to prevent damaging flow or pressure in the reverse direction. They can also be used in applications to maintain a system pressure for optimum system readiness and performance. Surprisingly, for a valve that performs such a critical function, a check valve incorporates very few components - the body, poppet, spring and retainer.
Give this essential valve its due
Considering its wide use, engineers, maintenance technicians and even end users should have a basic understanding of the function that this essential component serves in their systems. More often, however, that’s not the case. Generally, misunderstood in their function and importance, when you mention check valves, the responses range from “they just don’t work” to “never use them.” As stated earlier, a check valve exists to keep fluid flowing forward while helping to prevent reverse flow of fluids within a system. That makes them important for many reasons.
Where and why to use a check valve
Like any product out there, quality makes the difference. When that product is a check valve, you want the best on the market. There’s just too much at stake to consider anything else. That’s where Parker comes in. Parker’s check valves are engineered to perform under the most demanding circumstances. Offered in many configurations, our in-line style check valves are available in a variety of sizes, pressure ratings, flow capacities and crack pressures to satisfy most hydraulic system applications.
• The DT Series check valves cover the widest variety of applications. These hard seat check valves are offered in sizes from ¼” to 1-1/2” with the added benefit and convenience of compact design. Select sizes are also available in 45°, 90° and tee shape fittings which can help optimize system design by reducing labor and leak points. If you are unsure where to start looking for check valves, the DT Series is a great first option.
• The CV Series check valves are another hard seat check valve option for your application. Built using a rugged modular design that results in less pressure drop for increased performance in critical applications.
• The CPIFF Series check valves are a soft seat check valve option for your application. Soft seats are often used in applications where zero backflow is allowed.
Many standard configurations are available for purchase on parker.com. In stock items can ship within two business days. Learn more about Parker's complete line of check valves. Contact Quick Coupling Division for custom configuration options.
One of the most important valves for any system
Finally, a check valve is a relatively inexpensive component that protects significantly more expensive system components. A company can save thousands of dollars by implementing check valves and protecting these vital components. With so much on the line, it only makes sense to choose a reliable and high-quality product that can deliver under the most extreme conditions. And that’s what you can expect from Parker.
Contributed by Matt Walley, product sales manager, Quick Coupling Division, Parker Hannifin.
4 Apr 2019
Valve technology has come a long way with many available features. Gas and liquid multimedia valves that are used in chemical analysis such as Gas Chromatography/Mass Spectrometry (GC-MS) and Liquid Chromatography/Mass Spectrometry (LC-MS), two analytical techniques, are used for chemical analysis and have very critical requirements. In this blog, we will discuss key aspects to look for when replacing a solenoid valve, and possible upgrades to increase reliability and efficiency.
In chemical analysis, samples are separated using chromatography and identified with the mass spectrometer. Gas and liquid multimedia valves are used for head pressure control, flow path selection, and calibration in these analytical systems. These instruments can call for critical leak rates in the parts per fractions of a cc/min range; these are critical leak rates that require very high-end valves.
All valves are not created equal. When selecting a valve for analytical systems one must do his or her research. If you base your valve selection for your equipment on the lowest price, you'll likely experience equipment failures due to high leak rates over the valve's life and low repeatability. Analytical systems require valves that can withstand fast response time, high flow and repeated operations while maintaining precision control to ensure highly precise and accurate test results. The valves should be compared on leak rates, reliability, types of materials used and subsystem availability.
Leak rate is one of the most critical specifications for a valve used in Gas/Liquid (GC-LC) Chromatography, and Mass Spectrometry (MS). Instruments that leak can introduce outside contaminants into the sample flow stream and negatively affect the analysis. This means product failure. The original valve specifications must match to ensure it can withstand the necessary pressure and temperatures in the existing system. Valves used in GC, LC and MS should be tested using a helium mass spectrometer to check for porosity and permeability of the seat and seal. Other features that need to be considered are maximum pressure capability, surface finish, power consumption, and seat and seal.
When selecting valves in Gas or Liquid Chromatography and Mass Spectrometry (MS), reliability and repeatability are of utmost importance. For a valve to have repeatability it needs a long-life cycle, high yield rates and a proven track record. When determining reliability in a valve you must evaluate the design, quality of material and manufacturing process and controls of the product.
Hit and hold
In high duty cycle applications, multimedia solenoid valves can generate heat at full voltage. In order to reduce this heat, higher-end valve manufacturers use Hit and Hold circuits. Hit and Hold circuits allow valves to be fully powered and remain in that state for a short time before voltage and current are reduced to lower levels, while still allowing the valve to remain energized. This procedure allows the valve to stay open with much less energy. This will also allow the valve to generate much less heat and decrease the power draw. As an OEM look for this type of circuit option in a valve to reduce heat, increase cycle life and reduce energy consumption.
Type of material is crucial for valves with critical leak requirements. The term wetted material is important to understand. Wetted material is defined as any surfaces and/or components that are (potentially) exposed to or in direct contact with the medium under pressure. A few more important things to know before selecting a valve are permeation rate, compatibility with certain fluids (specifically what your system uses), and potential out-gassing that can occur.
Finally, look for the availability of subsystems. A subsystem is a pre-assembled module that includes tubing, fittings, regulators, valves on a manifold and other accessories. A subsystem will eliminate the need to maintain multiple vendors and reduce the overall bill of materials, provide integration between components, create one single stream for technical support and customer service, and cost reduction in assembly and labor time.
Above is a Mass Spectrometry system that features two Parker subsystems. The backfill subsystem and calibration subsystem are examples of Parker's ability to provide customers with complete solutions. In these subsystems, Parker’s Series 9 and Series 4 valves were specifically selected because they offer:
All valves can be customized with several attributes and come in complete pre-assembled subsystems to reduce time and cost. Parker is proud to be the only company capable of offering a complete product selection with integrating manufactured components and custom assemblies. We are eager to help you with all your precision gas and fluidics needs.
Parker Precision Fluidics has over 30 years of experience in developing valve and pump technologies. Our engineers specialize in helping Original Equipment Manufacturers (OEM) to update original valves that are producing low yields.
Our applications engineering team is always available to provide recommendations and customize equipment to customer specifications.
To learn more, visit Parker Hannifin’s Precision Fluidics Division or call 603-595-1500 to speak with an engineer.
Article contributed by Jonathan DeSousa, division application engineer, Precision Fluidics Division, Parker Hannifin.
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8 Mar 2019
Reliability is the quality of being trustworthy or of performing consistently well. Here at Parker, we’ve made reliability the focus of our products since the company was established; this has made Parker’s products synonymous with reliability. The new BTX-Connect diaphragm pump meets next-generation manufacturers' needs for reliability, portability, noise reduction, and adds additional advanced technology that is revolutionizing miniature diaphragm pumps.
Reliability meets innovation
The Connect motor features the newest technologies in the miniature diaphragm pump industry. The Connect motor is a brushless motor with a patented motor bearing design that is key to the pump's reliability. The only component that wears overtime in a brushless DC motor are bearings, unlike brushless motors that have brushes that mechanically connect the rotor and are consumed over time. The bearing system of the motor is critical in pumps because of the reciprocating radial load on the motor shaft. The BTX-Connect uses a custom bearing assembly system designed to remove all of the bearing internal play; this ensures a longer lifespan and significant noise reduction. Additionally, the BTX pump family includes a proprietary advanced elastomer material, which is specifically designed to withstand the constant flexing and loading within the diaphragm pump enabling the pump system to go well beyond 15,000 hours of continuous use.
Advanced serial communication
When designing the BTX-Connect pump, we considered the need for digital communication. Prior to the BTX miniature diaphragm pump, most pumps only had analog methods of speed control, PWM, 0-5V input, or on/off. The BTX breaks new ground by offering the option of connecting with a serial UART (Universal Asynchronous Receiver/Transmitter) that can provide motor speed measurements, internal temp, and fail-safe shutdown conditions if over temperature or over-current occurs. This is ideal for monitoring the pump's performance during the pump's lifespan.
In addition to all these standard features, the BTX offers accessories that can be purchased separately, including: the EZ-Mount base and Filter-Muffler. The EZ-Mount base enables easy installation in instruments and rubber isolators that reduce vibration. The Filter-Muffler offers even more noise reduction by filtering up to 10 microns. This pump is well suited for hospitals and in-home devices when patients require less noise and distractions.
The BTX has several options that include: single head, dual head, pressure only, vacuum only, and pressure/vacuum. See below chart for the single and dual head typical performance and ordering options. Contact Parker's Application Engineers for more options or special requirements. Additional motor options and configurations will be coming soon!
“The BTX-Connect is the next generation of miniature diaphragm pumps that are meeting next-generation devices needs”
David Sayer, test and reliability engineering, Parker Precision Fluidics
In conclusion, The BTX-Connect is the next generation of miniature diaphragm pumps by meeting and exceeding next-generation device manufactures needs. The brushless motor, custom bearings, advanced elastomer material, ultra-low noise, optimized counterbalance with advanced control options and capabilities are creating a new standard in miniature diaphragm pumps. The BTX is rated at 15,000 hours of continuous life at 12 psi.Key features
Our applications engineering team is always available to provide recommendations and customize equipment to customer specifications, call 603-595-1500 to speak with an engineer.
Article contributed by David Sayer, Parker Precision Fluidics Division. David has held multiple positions in engineering during his lengthy career, including positions in R&D, applications engineering, and test & reliability engineering. David's current position at Precision Fluidics focuses on validating reliability and uncovering improvement opportunities for Parker pumps.
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7 Mar 2019
We head into work each day with the expectation that we’ll put in our time and labor and then return home to our families safe and sound. The reality is though millions of Americans fall victim to workplace injuries each year. Some are as minor as a cut or scrape while others are much more severe and sometimes even fatal. Workplace incidents cause an enormous amount of physical, financial and emotional hardship for workers and their families. For organizations, the repercussions mean stiff penalties, violations and tarnished reputations.
Every seven seconds a workplace injury occurs in the United States. The numbers are even more staggering when analyzing the data and realizing this equates to 12,900 people hurt daily or 4.7 million a year, according to the National Safety Council. So, which industries are most receptive to workplace hazards? Manufacturing ranks in the top echelon of occupations with the largest number of injuries. With a growing demand for an increased workforce, these figures will likely continue to rise.
Most common workplace accidents
There are many hazards that put the health and safety of manufacturing workers at risk. From exposure to dangerous chemicals and corrosive cleaning solutions to confined spaces and heavy machinery; manufacturers have the difficult task of trying to address a wide array of safety issues.
One issue at the top of the list is oil. This chemical substance is prevalent in industrial equipment to make sure it is properly lubricated and operating. However, oil poses a wide range of health hazards to workers such as sensitization and irritation as well as physical risks including injury from slips and falls. Spills and leaks can happen at any point of the oil change process from draining and adding oil to disposing of the used oil.
Slips, trips and falls account for a third of all personal injuries and is a top cause of workers’ compensation claims. The risk is even greater for an individual performing oil duties, as they are exposed to toxic chemicals and susceptible to tripping and falling. The types of injuries include broken bones, cuts and lacerations, sprains, strains and tears. And most of these can easily be prevented.
Five key practices to avert a workplace incident:
Good housekeeping - If the plant floor is clean and well organized, an organization’s safety program can be effectively executed. Proper housekeeping should be a routine and be a part of each worker’s daily performance.
Wear proper shoes - Shoes are a critical component of personal protective equipment. Footwear that fits properly increases comfort and helps to prevent fatigue. Shoes or work boots with non-slip soles can also improve safety for employees.
Regulate individual behavior - The toughest of the three, it’s human nature to sometimes let our guard down and be distracted whether that’s being in a hurry or trying to manage multiple activities at once. It’s important for each individual to stay alert and pay attention to avoid becoming a statistic.
Standardize work instructions - Clear and concise work instructions and a standardized process reduce error and ensure the task at hand is completed safely and efficiently. Less variation in a process makes it easier to identify any existing safety issues.
Implement a new way to change oil to alleviate risk of workplace injury - In addition to the guidelines stated above, a safer working environment can be implemented by making simple adjustments to processes and procedures. For example, oil spills can be eliminated completely with a simplified approach to ensure safer and cleaner oil changes.
QuickFit™ Oil Change System from Parker provides a three-step process that allows oil changes to be done faster and more effectively. Oil is purged directly to the waste containment and then a vacuum is applied to extract the used oil from the pan. This same connection point is then utilized to refill the system with new oil through the filter. By applying one connection per compartment, it results in less variability during maintenance checks.
Reducing the number of steps in the process can eliminate any risk of safety hazards or spills, which improves an organizations’ bottom line by creating less consumable waste. Plus, QuickFit’s streamlined process helps to lower operating costs, increase profitability and reduce oil change time by 50 percent.
QuickFit applies ergonomic principles with a simplified design that grants easier access to even the most isolated and cramped components of an industrial application. This in return reduces exposure to fluids from fill to purge and greatly reduces the possibility of slips, trips and falls. Better safety conditions while changing oil saves time and costs on avoiding workplace injuries while increasing productivity.
Workplace safety cannot exist on best practices guidelines and policies alone. A safe working environment is established on a vision reflecting the way you do business through leadership, prevention and employee empowerment. And, a commitment to protecting the health and safety of people and the environments in which they operate. This demonstrates valid workplace safety and health that improves morale, productivity and the bottom line.
Contributed by Matt Walley, product sales manager, Quick Coupling Division, Parker Hannifin
6 Mar 2019