Basics of Differential Flow Devices

Orifice plate flow meter
Orifice plate flow meter
(courtesy of Siemens)
The differential flow meter is the most common device for measuring fluid flow through pipes. Flow rates and pressure differential of fluids, such as gases vapors and liquids, are explored using the orifice plate flow meter in the video below.

The differential flow meter, whether Venturi tube, flow nozzle, or orifice plate style, is an in line instrument that is installed between two pipe flanges.

The orifice plate flow meter is comprised the circular metal disc with a specific hole diameter that reduces the fluid flow in the pipe. Pressure taps are added on each side at the orifice plate to measure the pressure differential.

According to the Laws of Conservation of Energy, the fluid entering the pipe must equal the mass leaving the pipe during the same period of time. The velocity of the fluid leaving the orifice is greater than the velocity of the fluid entering the orifice. Applying Bernoulli's principle, the increased fluid velocity results in a decrease in pressure.

As the fluid flow rate increases through the pipe, back pressure on the incoming side increases due to the restriction of flow created by the orifice plate.

The pressure of the fluid at the downstream side at the orifice plate is less than the incoming side due to the accelerated flow.

With a known differential pressure and velocity of the fluid, the volume metric flow rate can be determined. The flow rate “Q”, of a fluid through an orifice plate increases in proportion to the square root the pressure difference on each side multiplied by the K factor. For example if the differential pressure increases by 14 PSI with the K factor of one, the flow rate is increased by 3.74.


A Clean in Place (CIP) Mag Flow Meter with Pasteurized Milk Ordinance (PMO) Approvals

magmeter with PMO approval
Magmeter with PMO approval
(courtesy of SIEMENS)
Dairies have been hampered by a limited selection of flowmeters to process raw ingredients and maximize productivity. Faced with limited choices for instrumentation, the Food and Beverage Industry is always interested in new products and certification. In this case, the product is a "Clean in Place" (CIP) electromagnetic flow meter (Magmeter) with Pasteurized Milk Ordinance (PMO) approvals.

Clean-in-place (CIP) is a method of cleaning the interior surfaces of process equipmentpipes, vessels, and fittings, without disassembly. This is an invaluable technology in the dairy, brewery, beverage, processed foods, cosmetics, and pharmaceutical industries by providing a cleaning process which is faster, far less labor-intensive, more consistent, and with less chemical exposure to workers.

The Pasteurized Milk Ordinance, is published by the Food and Drug Administration further defines minimum standards and requirements for Grade A milk production and processing.

A Magmeter is an excellent flowmeter choice for dairy use because it is unaffected by suspended solids, viscosity, and temperature challenges typically found in food and beverage applications. Additionally, magnetic flowmeters provide:
  • Ease of installation with Tri-clamp fittings.
  • Stainless steel, obstruction less flow performance meets all sanitary requirements and is 3A certified.
  • Suitable for CIP and SIP cleaning.
  • IP67 I NEMA 4X rating that is upgradeable to IP68 /NEMA 6P.
Carrying a PMO approval provides the dairy with confidence and assurance that the magnetic flowmeters have been tested and approved precisely for use in their plant.

For more information, see the document below:

Remote Sensing of Gases Directly in the Process

Electric power plant
Electric Power Plant
Industrial operations, whether for direct process control or emissions compliance monitoring, have a need for accurate, reliable measurement of specific gas concentrations within a flowing medium. Tunable diode laser spectroscopy, packaged for industrial use, provides a number of substantially positive attributes.

  • Rapid measurement.
  • Can be focused on a specific component of interest.
  • Multi-channel operation provides analysis of several components.
  • In situ installation can provide direct measurements within a stack, pipe, or duct without sample handling or conditioning.
  • Can measure NH3, HF, HCl, H2O, CO, CO2.
  • Internal reference cell provides long term stability.
  • Some models have continuous automatic calibration.
Siemens manufactures a line of tunable diode laser gas analyzers for industrial applications. In the company's own words, here is a basic description of how it works.

As a tunable diode laser-based technology this in-situ device enables high-performance measurements. The sensors (transmitter and receiver) are meant to be mounted directly on the process with no need of sampling systems. Laser light is sent from the transmitter, passing through the process gas, arriving at the detector on the receiver side. The measurements are carried out on-line with a very short response time permitting fast and effective cost-savings in process control. The laser characteristics allow single-line spectroscopy free of interferences. Since the band width of the laser light is extremely narrow, only the gas component of interest will interact with it. Other process influences, such as dust and temperature, are easily eliminated due to the excellent inherent compensation capabilities of this technique.


There is application assistance and more detailed information available from knowledgeable sales engineers in all localities. Combine your process mastery with their product application resources to meet the challenges posed by modern industrial process operation.



Basic Programming for the SITRANS F M Electromagnetic Flowmeter

The video below explains the basics of programming the SITRANS F M electromagnetic flowmeter.

The SITRANS F M MAG 5000 & 6000 are microprocessor-based transmitters engineered for high performance, easy installation, commissioning and maintenance. These transmitters are truly robust, cost-effective and suitable for all-round applications. The MAG 5000 has a measuring accuracy of ± 0.4% of the flow rate (incl. sensor), while the MAG 6000 has a measuring accuracy of ± 0.2% of the flow rate and can be fitted with optional plug-in communication modules.


Other Members of the SITRANS F M MAG Family:

SITRANS F M MAG 1100 is a wafer design sensor in stainless steel with highly resistant liners and electrodes and is designed for the general industry environment. The flangeless wafer design meets all flange standards. The SITRANS F M MAG 1100 is used in all industries where the corrosion-resistant stainless steel housing and the highly resistant liner and electrodes fit even the most extreme process media.

The SITRANS F M MAG 1100 F sensor is especially designed for the food & beverage and pharmaceutical industries and is available with hygienic and flexible process connections. It meets all sanitary requirements and is 3A certified and EHEDG approved.

The SITRANS F M  MAG 5100 W  with its patented liners of hard rubber NBR or ebonite and EPDM is a sensor for all water applications such as ground water, drinking water, cooling water, waste water, sewage or sludge applications.

SITRANS F M MAG 3100 is an electromagnetic flow sensor with a large variety of liners, electrode material and with grounding electrodes as standard, all this ensures a perfect fit for almost every flow application.
Also, measuring electrodes which are capable of withstanding the most extreme processes and various liners are available.

The SITRANS F M  MAG 3100 P sensor  is designed to meet the most common specifications within the chemical and process industries. It has PTFE or PFA liners and Hastelloy electrodes being the ideal combination. The fully welded construction provides a ruggedness that fits almost every flow application.

The SITRANS F M MAG 6000 I and the SITRANS F M MAG 6000 I Ex de transmitters have an measuring accuracy of + 0.2% of the flow rate and are designed to meet the demands of the process industry. Both versions are based on a microprocessor with a built-in alphanumeric display.

High Performance, Low Cost, Industrial Safety Device

Series One Safety Transmitter
Safety Transmitter
Sadly, There are too many recent examples of catastrophic industrial accidents. New safety technologies exist today that can prevent or mitigate future disasters. The philosophy of safety is changing - the focus on plant safety has changed from reactive to a proactive approach. End users have a new sense of urgency toward safety processes.

The United Electric Controls (UE) Series One is a SIL-certified (SIL stands for safety integrity level) transmitter designed solely for safety, alarm, and shutdown applications, with reliability, speed, and fewer nuisance trips. It is also designed for both greenfield and brownfield installations, and is cyber secure.

A typical safety loop consists of sensors (such as a pressure transmitter), controllers, and final control elements. Most SIL-rated pressure transmitters require 300ms to communicate with the controller and up to 500ms for the controller to send a signal to the final control element (such as a valve). This may not be fast enough for critical applications. By connecting the One Series Safety Transmitter directly connected to the final control element, the signal speed is reduced to 100ms - a huge time savings when you're in the midst of a disaster. When used with blowers, pumps and compressors, the One Series makes up a complete safety system with a self-contained sensor, controller, and final control element (the switch) capable of SIL2 without additional safety instrumented function (SIF) components.

The below document provides detailed information about the Series One.


For more information, contact:

Ives Equipment
877-768-1600
www.IvesEquipment.com


Township Water Authority Uses Ultrasonic Clamp-On Flowmeters to Avoid Surcharges for Exceeding Peak Limits

Ultrasonic Clamp-On Flowmeter
Ultrasonic Clamp-On Flowmeter
(courtesy of Siemens)
Reprinted with permission from Siemens Process Instrumentation

A suburban township buys their drinking water from a major municipal water district. The township’s water distribution system network has four connections to the larger municipality’s water transmission main. The municipality has many customers and has implemented contracts with each of its wholesale customers that limit the peak flows and the time of day in which they may occur. If the wholesale customer exceeds the limit, they are assessed significant surcharges.

Because of the potential surcharges, the wholesale customers can financially justify investing in solutions to better control their water demand, minimize the usage peaks, and control what time of day they occur. These measures include elevated water storage towers, as well as control valves at each of the connections to the municipal provider’s transmission main.

Challenge

The major municipal water district owns and operates “metering pits” with magmeters immediately upstream of the control vaults owned by each customer. However, as a rule, the signals from these meters are not made available to the any wholesale customers on a real time basis. Wholesale water customers are only given datalog summary reports from these meters on a routine schedule for billing purposes.

Without a method of measuring flows or getting flowrate data from the water district in advance, the township customer had no means of knowing, in real-time, the amount of flow they drew from the transmission main. Therefore, they did not know if or when they were exceeding the contractual peak flowrate limits and incurring significant surcharges from the water district until they were billed.

The township customer needs to know the flowrate at each of its four connections to the transmission main so they may control how much is being drawn at each site. They also need the total flow from the municipality’s transmission main, so they do not exceed their contractual peak demand.

The control vaults were initially installed without flowmeters. The intention was to use control valve position and upstream/ downstream (differential) pressure readings to estimate the flow through the control valve using the characteristic curve of the valve. This proved to be too complicated and cumbersome for their SCADA system to effectively implement.

Solution

The local Siemens representative worked with the township and their engineer to find a solution to measure the flow rate and totalize the volume of flow at each of the customer’s control vault sites. The most significant challenge was the piping configuration. All of the vaults were previously constructed without provisions for a flowmeter. The control valve vaults are very tight. The Siemens representative used a Siemens ultrasonic clamp-on flowmeter demo kit to demonstrate the technology to the customer, and prove that it would reliably meet their objectives. The vault with the worst piping configuration was selected for the demonstration. That would demonstrate that if the flowmeter would work in the worst site, it would work at the other three sites as well. However, if the Siemens flowmeter didn’t work in that site, the township would need to look at alternate, more costly, flow measurement technology for a solution. Within minutes of arriving on site, the unit was installed and providing reliable readings. The unit was allowed to log for a period of three days. After that, it was retrieved and compared to the readings from a competitive magmeter in the municipal water provider’s metering pit.

The logger on the Siemens clamp-on flowmeter provides helpful information on the quality of the velocity and flow measurements. This logged information helped establish and solidify the confidence of the owner and the engineer that the Siemens clamp-on meter would work for these applications.

Four key reasons the customer chose Siemens flowmeters:
  • The Siemens clamp-on flowmeter has the capability to make the tough measurements and provide information on the quality of those measurements. 
  • The attentive, professional and knowledgeable service they received from the local Siemens representative was well supported by Siemens personnel. 
  • The local representative provided the field service to install the transducers on the pipe, and commission the transmitters. 
  • The local representative conducted the demonstration and assisted the township engineer with their evaluation of the ultrasonic clamp-on flowmeter vs. magmeters owned by the water district. The major water district supported the Siemens ultrasonic clamp-on technology used by the township customer after they attended a Siemens Level & Flow Seminar held in their district. 
Benefits
  • Cost Savings - If they were not able to use the Siemens ultrasonic clamp-on flowmeters, the customer would have had to excavate and install a below-grade vault to house a magmeter and associated isolation and by-pass valves, along with conduit and wiring, at each of these four sites. This would have required cutting the water pipe and then going through a cumbersome disinfection process, both of which would have required lengthy permitting and costly testing. Further, some of the sites really had little or no room to accommodate such a structure or piping modifications. It is estimated these modifications would have totaled over $250,000. In comparison, the customer ended up spending $25,000 for the meters, and field service to install some conduit from the pipe to an existing above grade SCADA panel. 
  • Time Savings - The customer had already made improvements to the distribution system and installed four new control vaults. Their construction contracts were closing and they could not use their water tower until the new flow controls were added. Time was a critical factor. The customer saved 3-6 months in time by using the Siemens clamp-on flowmeters instead of having to construct new vaults to house magmeters. 
  • Improved Process Reliability - Now that the meters are in place, the customer can control how much water they are taking from the water district at each of these four locations, and ensure they do not exceed their contractual peak. They can now also properly manage the fill and draw of their elevated storage tank to offset peak demands, and fill/store during periods of low demand. 

Step-by-Step Instructions for Installing a Samson 3277 Actuator

The Samson 3277 is a pneumatic linear actuator suitable for attachment to Samson Series 240, 250, 280 and 290 control valves, as well as the type 3510 Micro-flow valves. Designed with a rolling diaphragm and internal springs, the Samson 3277 is popular because of its low overall height, fast response, low friction, and its ease to maintain. Attaching the actuator, or replacing one, can be done in minutes, without the need of special tools.


This video provide step-by-step instruction on how to install the 3277 actuator.