Tuesday, April 17, 2018

Flow-Tech, Inc. Serving Maryland, Washington D.C. and Virginia

Flow-Tech is a manufacturer’s representative and stocking distributor of process instrumentation and calibration equipment in Maryland, D.C and Virginia specializing in the Industrial Process, Control, and Test / Measurement markets.

https://flowtechonline.com
410-666-3200 MD
804-752-3450 VA

Monday, April 9, 2018

What is a Pressure Transmitter?

Differential pressure transmitter
Differential pressure
transmitter (Yokogawa)
A pressure transmitter is a transducer that converts pressure into an electrical signal it outputs both analog and digital signals corresponding to the pressure. A pressure transmitter measures three phenomena: differential pressure; gauge pressure; and absolute pressure. The most common and useful industrial pressure measuring instrument is a differential pressure transmitter. This instrument senses the difference in pressure between two ports and produces an output signal with reference to a calibrated pressure range.

Industrial Applications of Pressure Transmitters

Pressure transmitters are commonly used to measure the pressure inside of industrial machinery or in industrial processes. They are used in various industries such as oil and gas, refining, chemical, pharmacy, and so on.

Pressure Transmitters in Industry

Pressure Transmitters in Industry
Pressure Transmitters in Industry
Pressure transmitters are widely used in industry to measure flow, level, and pressure. There are unlimited industrial applications. Oil and gas flow metering applications are found onshore, offshore and in subsea. It is also often used for monitoring filters in water and effluent treatment plants, monitoring sprinkler systems, and remote sensing of heating systems for steam or hot water. It can monitor pressure drops across valves and can be used to monitor pump control.

Differential Pressure for Flow Measurement

DP flow measurement is one of the most common applications for differential pressure transmitters by measuring the difference in fluid pressure. While the fluid flows through a pipe, it is possible to calculate the flow rate for differential pressure flow measurement. A primary and the secondary element are used. The primary element is designed to produce a difference in pressure as the flow increases. There are many different types of primary element, the most common being the orifice plate, Venturi flow nozzle, and pitot tube. The secondary element is a differential pressure transmitter. It is designed to measure the differential pressure produced by the primary element as accurately as possible. In particular it is important that the differential pressure measurement is not affected by changes in the fluid line pressure, temperature, or other properties such as ambient temperature. A good DP transmitter will ensure that the differential pressure is measured accurately regardless of other changing parameters and will reliably transmit a signal to represent the differential pressure. The DP flow transmitter output signal may also include square root extraction for flow calculation, although it is common for this function to be handled in a control system. In a typical control loop, the transmitter signal is fed to the controller whose output is used to regulate the flow rate through a control valve.

Differential Pressure for Flow Measurement
Differential Pressure for Flow Measurement


Differential Pressure for Level Measurement

Differential pressure transmitters can also be used for tank levels by measuring the pressure. The transmitter is installed at the bottom of the tank whose level is to be detected. In case of a sealed tank, a transmitter with capillaries measures a differential pressure between the upper side and the bottom side. The liquid inside the tank at the bottom creates pressure which is higher than the pressure at the top. The difference in these pressures can be used to calculate the level. In case of an open tank, the transmitter measures the differential pressure between the liquid inside the tank and the reference atmospheric pressure. In a typical control loop, the transmitter signal is fed to the controller whose output is used to regulate the tight level through a control valve.

Differential Pressure for Level Measurement
Differential Pressure for Level Measurement

Friday, March 30, 2018

Flow-Tech, Inc. - Process Instrumentation, Calibration, Safety, Measurement and Control

Flow-Tech is a manufacturer’s representative and stocking distributor of process instrumentation and calibration equipment in Maryland, D.C and Virginia specializing in the Industrial Process, Control, and Test / Measurement markets. Customers include: Power and Chemical plants, OEM’s, System Integrators, Municipalities, Engineering Firms, Universities, Medical Centers, and Research / Metrology Labs. Products and systems focus on the measurement and control of: flow, pressure, temperature, and level; as well as calibration equipment, analyzers, gas detection, annunciators, and data acquisition. Flow-Tech also provides field service, turn-key systems, equipment start-up, service contracts, and training.


Tuesday, March 27, 2018

Understanding Flow Sensing Technologies

When selecting a flow sensor, flow meter, or flow switch, one of the first considerations is always the process media: air, gas, steam or liquid. Some flow sensing technologies measure gas, some are better at liquids, some are best for a single media, such as steam, and others are good in multiple media. The industry’s major flow sensing technologies now available include:
Thermal
Thermal flow meters.
Depending on the process media and your application’s requirements, all of these technologies have their advantages/ disadvantages. By considering the process media to be measured, as well as your plant’s equipment and layout, environmental conditions, maintenance schedules, energy cost and ROI, you will be able to narrow the field to one or two best choices.

Coriolis
Coriolis
Coriolis (Mass): Coriolis flowmeters use the oscillating movement of two symmetric metal tubes that are made to vibrate from an internal driver coil.  When liquids or gases flow through the tubes, a phase shift occurs (like you see in the hose) and pickups measure the “twist” and then relate that value to the actual flow. In other words, the amount of twist is proportional to the mass flow rate of fluid passing through the tubes. The greater the twist, the larger the distance between, and the greater the flow.

Differential Pressure: 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. 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 and measures the pressure drop across the flow restrictor and equates it to flow.

Magnetic
Magnetic
Electromagnetic: Magnetic flow meters, also called electromagnetic flow meters or "magmeters",operate on a very simple principal. An electrically conductive liquid moving through a magnetic field will generate a voltage that is related to the velocity of the liquid.

Positive Displacement: Provides a direct indication of actual volumetric flow rate. The fluid motion drives the mechanical assembly. As the fluid motion drives the positive displacement flowmeter assembly, its rotational, oscillating, or other regular movement is counted, often by electronic means using magnetic pickups on moving assembly. There are a number of different positive displacement flowmeter designs including oscillating piston, gear, nutating disk, rotary vane, and diaphragm.
Thermal
Thermal

Thermal (Mass): Measure flow by delivering heat into the flowing media and measuring the loss of heat between temperature measurement points. They are popular because they provide unrestricted flow, contain no moving parts, work well on large or small diameter pipes, provide accuracies over a wide range of flow rates, do not require temp/press compensation, and provide mass flow instead of volume.

Turbine
Turbine
Turbine: These types of flowmeters operate under the simple principle that the rotation of the turbine will be constant as the turbine is acted upon by a fluid passing through the flowmeter. The rotational velocity of the turbine is then interpreted as output, allowing for the operator to consistently monitor the flow rate of the process fluid. They are easy to maintain and reliable.
Ultrasonic
Ultrasonic

Ultrasonic: Measure, via sound waves, the velocity of liquid flowing through a pipe.  Doppler shift technology reflects ultrasonic beams off sonically reflective materials. The transit time method exploits the fact that the transmission speed of an ultrasonic signal depends on the flow velocity of the carrier medium. The use of ultrasonic flow technology is most used in the oil, nuclear, wastewater, pharmaceutical, food and beverage industries.
Variable Area
Variable Area

Variable Area: Measures flow rate by allowing the cross-sectional area the fluid travels through to vary, causing a measurable effect. Flow measurement is performed according to the float principle. Used to measure many different types of liquids and gases passing through closed piping.

Vortex Shedding
Vortex
Vortex Shedding: Refers to the phenomenon wherein flowing gas or liquid forms vortices around a solid obstruction placed in the flow path, which can be measured to calculate volumetric or mass flow. Measure the volumetric flow rate of steam, gas, and low viscosity liquids.

Contact Flow-Tech for any industrial or commercial flow application by calling 410-666-3200 in Maryland, or 804-752-3450 in Virginia. Visit https://flowtechonline.com.

Wednesday, March 21, 2018

Draeger Gas Detection Transmitter and Feature Selection Charts

Here are two charts to help you select Draeger Gas Detection Transmitters.

The diagram below provides a flow chart on how to properly select a Draeger transmitter.

Draeger Transmitter Selection Flow Chart
Draeger Transmitter Selection Flow Chart (click for larger view).

The table below provides a feature comparison table for most Draeger transmitters (it does not show the PointGard 2100, but the P8100 features are very similar, if not identical).

Draeger transmitter feature comparison table
Draeger transmitter feature comparison table
(click for larger view).

Tuesday, March 13, 2018

The Ideal Flow Monitoring System for a Drinking Water Supply Network

FLEXUS by FLEXIM
The ideal drinking water flow monitoring system.
Wouldn't it be great if you had a closely woven system of measuring points that monitor flow rates in the drinking water supply network as seamlessly as possible and leaks and hydrological problem zones would be detected and corrected as quickly as possible?

Unfortunately the reality looks somewhat different. Installation of conventional flow measuring points in a drinking water supply network incurs high costs and an enormous amount of effort to maintain.

FLEXUS by FLEXIM

FLEXIM is a technology leader in the field of non-invasive flow measurement with clamp-on ultrasonic technology. FLEXUS clamp-on ultrasonic systems measure according to the transit time difference method. Since the transducers are mounted on the outside of the pipe no interventions in the pipeline system are necessary. the drift free and long-term stable acoustic measuring method detects even the smallest flows, even those that lie below the response threshold of conventional flow meters. Therefore, fluxes is the ideal instrument for monitoring minimum flow rates at night, and thus the key to effective consumption and leakage monitoring.

With FLEXUS, a flow measuring point can be conveniently setup within half a working day without supply interruptions with out affecting traffic, and without a heavy lifting device.  For the installation of the ultrasonic measuring system, only temporary access to the pipe has to be created.  The service engineer first checks the pipe dimensions. Sturdy mounting devices made of stainless steel ensure that the flow transducers are permanently stable when installed. Even on the transducers themselves, nothing can break. The cable and sensor are firmly connected. No plug can come loose. Water or dirt cannot penetrate anywhere. The ultrasonic transducers have IP68 protection and can operate continuously underwater. Coupling pads, made of elastic plastic, ensure permanent optimal acoustic coupling to the pipe without any wear. Thanks to their unique internal temperature compensation, FLEXIM transducers do not show any drift during temperature fluctuations. Setup of the measuring point on the pipe is completed by positioning and fixing the ultrasonic transducers. Now only the connection to the measuring transmitter, housed in the switch cabinet, has to be created. The calibration data of carefully paired and calibrated transducers are stored on one chip and are automatically transferred to the measuring transmitter. A zero point calibration on site is not necessary. Where nothing flows, FLEXUS reliably measures zero.

Measurement in Progress

The measuring results are either transmitted by cable or wirelessly via GSM to the process control system. Practical self-diagnosis functions allow for safe evaluation of the measurement quality. Done. Now the measuring point can be refilled underground since the pipe line remained completely intact. There was no need to flush the pipe and no need for the final leak test. In the office, the measured values can be visualized and evaluated on a computer.

Sunday, February 25, 2018

Bently Nevada 3500 Series Machinery Monitoring System Datasheet

Bently Nevada 3500 Series Machinery Monitoring System
Machine condition monitoring combines hardware, software, and service and support – providing a broad, connected view of your operations. Together, they enable your plant to mitigate risk, boost safety, and reduce maintenance costs, while improving equipment reliability, uptime, and efficiency.

Hardware monitoring systems and sensors protect your equipment and collect rich condition monitoring and diagnostic data for analysis. Condition monitoring and diagnostics software connects real-time and historical data from production equipment to help you anticipate failure before it occurs. With scalable deployment and ongoing support service offerings, you can ensure that you’re maximizing the value of your condition monitoring program.

The Bently Nevada 3500 Monitoring System provides continuous, online monitoring suitable for machinery protection and asset condition monitoring applications. It represents our most capable and flexible system in a traditional rack-based design and offers numerous features and advantages not provided in other systems.

Download a PDF version of the Bently Nevada 3500 System datasheet here, or quickly review the embedded document below.

For more information, contact Flow-Tech in Maryland by calling 410-666-3200, in Virginia by calling 804-752-3450, or by visiting https://flowtechonline.com.