Differential Pressure Gauge for Level Indication on Liquefied Gas Tanks

A differential pressure gauge can be used to
indicate liquid level in tanks of liquefied gas
Image courtesy Wika

Wika, globally recognized leader and innovator in the design and manufacture of pressure and temperature gauges, provides an enormous number of variants and models of its basic pressure gauge. Many of the gauges are targeted at specific applications, and incorporate a range of design and operational features to accommodate the needs of those applications.

The Cryo Gauge is designed to provide indication of the level of liquid in liquefied gas tanks, but can also serve in some other related applications. For cryo tank applications, several available measuring cells provide operating ranges that cover the most commonly used tank sizes and gas types. An optional manifold with a separate pressure gauge provides connectivity and an indication of working pressure, all in one compact station. Options for analog output, level switches, and remote data transfer are part of the flexible configuration.

More detail on the Cryo Gauge is provided in the datasheet included below. Whatever the application, share your pressure measurement challenges with process measurement experts, leveraging your own knowledge and experience with their product application expertise to develop effective solutions.

Process Differential Pressure Gauge from MSJacobs-Cali

Award Winning Flow Measurement Instrument

Flexim F704 Ultrasonic Flow Meter
Image Courtesy Flexim

Flow Control Magazine, which targets solutions for fluid movement, measurement and containment, handed out its annual Innovation Awards recently. Among those receiving honorable mention was Flexim Americas Corporation, for the Fluxus Cryo that provides noninvasive measurement of cryogenic fluids. Special design adaptations prevent ice build up on the measurement apparatus that that can plague other technologies.

Ultrasonic flow measurement offers some distinct advantages over other available methods, with high accuracy, no intrusion into the media, and no moving parts. While the award was specifically for a cryogenic application, Flexim ultrasonic flow measurement instruments are available for an extensive array of applications.

For more information, share your flow measurement requirements and challenges with process instrumentation experts, leveraging your own process knowledge and experience with their product application expertise to develop effective solutions.

Simple Tech Drives Reliable Remote Power Unit

The Qnergy remote power unit utilizes a simple
Stirling engine to generate electric power.
Image courtesy Qnergy

M.S. Jacobs and Associates handles the Qnergy line of remote power units, providing electric power to off-grid locations or standing as a backup power source for critical operations. Wherever backup or independent source electric power is needed, Qnergy remote power units can serve as a reliable and economical power source, requiring little to no maintenance.

The technology under the hood in the Qnergy power units is a Stirling engine, adapted and improved by decades of innovation. The engine derives energy input via external combustion, enabling the use of a variety of fuels.

• Natural gas
• Propane
• Ethane
• Biogas
• And others

The Stirling engine utilizes a floating piston with no contact points to wear. The system requires no lubrication or regular maintenance, very positive attributes for a remote power unit. Share your project requirements and challenges with application specialists, combining your own knowledge and experience with their product application expertise to develop effective solutions.

Qnergy Remote Power Generators from MSJacobs-Cali

Bag Filter Housings For Liquid Filtration

Filtration is a common processing step in many liquid based industrial operations. Applying the right degree of filtration or particle capture helps assure a predictable level of output quality. Selecting a bag filtration unit should incorporate a number of factors to meet the goal of good performance with a minimized personnel commitment to maintenance.

• Materials of construction must be compatible with the process liquid, as well as providing resistance to the effects of their surrounding environment.
• Connection size and type should be adequate for anticipated flow rate and compatible with the connected piping system.
• Installation location should permit all around access for service, including clearance for opening the unit for filter bag changes.
• Pressure rating of the housing must meet any applicable requirements of the process, jurisdiction or industry standards.
• Provide an adequate arrangement to isolate the filtration unit from the fluid system, perhaps with a bypass loop, to allow for in-place access.

The short video illustrates some of the salient features of bag filtration housings that accommodate multiple filter bags. Share your filtration requirements and challenges with processing specialists, leveraging your own processing knowledge and experience with their product application expertise.

Pressure and Vacuum Sealed Feedthrough Fittings

Several versions of vacuum chamber feedthrough fittings.
Image courtesy of Spectite, Inc.

The passage of sensor tubes, electrical conductors, or similar items through the wall of a pressure vessel requires the use of a special fitting that accommodates the physical passage through the vessel wall without compromising the vessel performance. The provision of the right connectors, mounting fitting, and sealant assure simple and effective installation of the feedthrough fitting. Vacuum and pressure feedthroughs are an important part of the physical signal path and the vessel barrier wall, maintaining the integrity of the vessel or chamber containment while facilitating the passage or placement of power, sensors, or other items.

There are countless applications for feedthroughs, resulting in a broad offering of body styles, sealants, connections, and customized arrangements to meet any challenge. Spectite manufactures a broad range of vacuum and pressure feedthroughs, any of which can be customized to meet an application challenge. Share your project requirements with a product specialist, leveraging your own process knowledge and experience with their product application expertise to develop an effective solution.

Sealed Vacuum and Pressure Feedthrough Fittings from MSJacobs-Cali

Electronic Pressure Switches

Electronic pressure switch in NEMA 4 enclosure.
Image courtesy of Ashcroft

A pressure switch is a device that detects and responds to fluid pressure. Pressure switches use a variety of sensing elements such as diaphragms, bellows, bourdon tubes, pistons or electronic sensors. In all but the electronic sensor versions, the movement of the sensing element, caused by pressure fluctuation, is transferred to a set of electrical contacts to open or close a circuit. Electronic pressure switches utilize a sensor signal and circuitry to control switch activation.

The normal status of a switch is the resting state with stimulation. A pressure switch will be in its normal state when low or minimum pressure is applied. For a pressure switch, normal status is any fluid pressure below the trip threshold of the switch.

One of the earliest and most common designs of pressure switch was the bourdon tube pressure sensor with a mercury switch. When pressure is applied, the bourdon tube flexes enough to tilt the glass bulb of the mercury switch so that the mercury flows over the electrical contacts, thus completing the circuit. the glass bulb tilts far enough to cause the mercury to fall against a pair of electrodes, thus completing an electrical circuit. Many of these pressure switches were sold on steam boilers. While they became a de facto standard, they were sensitive to vibration and breakage of the mercury bulb.

Pressure switches using micro type electrical switches and force-balanced pressure sensors is another common design. The force provided by the pressure-sensing element against a mechanical spring is balanced until one overcomes the other. The tension on the spring may be adjusted to set the tripping point, thus providing an adjustable setpoint.

One of the criteria of any pressure switch is the deadband or (reset pressure differential). This setting determines the amount of pressure change required to re-set the switch to its normal state after it has tripped. The differential pressure setting of a pressure switch should not to be confused with a differential pressure switch, which actually operates on the difference in pressure between two separate pressure input ports.

Electronic pressure switches provide some features which generally are considered advantageous to mechanical designs.

• No mechanical linkage between sensing element and switch, all electronic.
• High cycle rates are possible.
• High levels of accuracy and repeatability.
• Some models have additional features, analog output, digital display, auxiliary switches, and more.

When selecting pressure switches you must consider the electrical requirements (volts, amps, AC or DC), the area classification (hazardous, non-hazardous, general purpose, water-tight), pressure sensing range, body materials that will be exposed to ambient contaminants, and wetted materials.

Whatever your pressure measurement application, share your challenges with a fluid measurement and control specialist, combining your own knowledge and experience with their product application expertise to develop effective solutions.

Electronic Pressure Switch for Industrial Applications from MSJacobs-Cali

Thermal Flow Meters

Magnetrol TA2 thermal flow meter configured
for insertion mounting.
Image courtesy Magnetrol International 

There are numerous methods and technologies adapted for the measurement of fluid flow, each with its own set of positive attributes and limitations. Understanding the basic operating principles behind each is useful for effective selection of a technology to be applied on a specific application. One technology long employed for continuous fluid flow measurement is thermal dispersion. The operation of a thermal flow meter is as simple as placing a heated object into a moving stream. The amount of heat drawn away, or dispersed, from the heated object is a measurable quantity that is directly proportional to mass flow rate. This is similar in concept to a principle commonly observed in wind chill where someone perceives the temperature to be colder than it actually is at the moment of measurement.

One example of a thermal mass flow meter is a hot wire anemometer, with which air speed is measured via a metal wire charged with an electric current. The faster the air moves around the wire, the more the temperature of the wire will correspondingly drop. The electrical power required to keep the temperature of the wire constant is directly proportional to the flow rate of the air moving past the wire. However, thermal flow meters are inherently used to measure mass air flow and not volumetric air flow.

A common application of thermal flow meters is mass air flow measurement for combustion control, such as in engines and boilers. Maintaining fuel to air ratios in a range resulting in efficient combustion is essential to controlling fuel costs and the level of regulated emissions. Keeping combustion efficient relies on a controller’s ability to modify the combustion air mass flow rate to match the demand for fuel under changing load and input conditions. Thermal dispersion technology can be applied to gases or liquids, making the range of applications very broad.

Typically, thermal mass flow meters used in processing industries will have a flow tube or insertion probe with two temperature sensors, one which is heated and the other which is not. The heated sensor serves as the mass flow sensor, meaning it will cool at a rate directly dependent on mass flow. The purpose of the second temperature sensor is to deliver an accurate measure of fluid temperature. Various processing methods are employed to determine the degree of thermal dispersion, but all are related to the same basic principal.

One of the best applications for thermal mass flow meters is at a particular point of a flow stream, where the flow meter can be inserted or installed to measure a specific amount of fluid being used in the process, such as the amount of gas being sent to a flare. Their design simplicity and ease of production allows thermal flow meters to be very compact. Some are even coupled with built-in throttling mechanisms and other control devices, incorporating measurement and control functions into a single integrated device.

Share your flow measurement requirements and challenges with an instrumentation specialist, combining your own process knowledge and experience with their product application expertise to develop an effective solution.