Direct Steam Injection Humidifier Replacement in Large Hospital

Direct Steam Injection Humidifier Replacement
at St. Louis Children's Hospital

The St. Louis Children’s Hospital is one of the premier children’s hospitals in the United States. It serves not just the children of St. Louis, but children and their families from across the world. The hospital provides a full range of pediatric services to the St. Louis metropolitan area and primary service region covering six states. As the pediatric teaching hospital for Washington University School of Medicine, the hospital offers nationally recognized programs for physician training and research. The hospital employees 3,000 people as well as 800 medical staff members. There are also 1,300 auxiliary members and volunteers on-site.

St. Louis Children’s Hospital was undergoing a significant renovation and determined that the original direct steam injection humidifiers that were installed over 30 years ago needed to be replaced. Within 30 years, they had only experienced minor issues due to the age and use of the humidifiers. Most issues were labeled as manifold o-ring leaks or actuator leakage (either seal kits or diaphragms).

St. Louis Children’s Hospital consulted with their local Armstrong representative, Mead O’Brien, and looked at using direct steam injection humidifiers with electric actuators versus the atmospheric steam generating humidifier. Due to the maintenance, space concerns, and, most importantly, the controllability, Mead O’Brien suggested direct steam injection humidifiers.

When replacing humidifiers during a renovation it is important to analyze the absorption distance. There are many different variables that can affect the absorption distance and, in this case, guidelines and regulations have changed over 30 years since original installation. The amount of outside air brought into the space directly affects the RH levels, and in the healthcare industry, the minimum requirement of fresh air has changed multiple times in the past 30 years. Because of this, some installations required the use of multiple manifolds to shorten the absorption distance.

During this first phase of the renovation, thirty-nine (39) new steam humidifiers were installed. Thirty-four more we supplied the following year..

In addition, the following Armstrong products were also installed:

• Six Pressure Reducing Valves 
• Three Electric Condensate Pumps 
• One Armstrong Flo-Rite
• Five VERIS Flow Meters

Because of the customer’s relationship with their local Armstrong representative, St. Louis Children’s Hospital received a quality solution that was designed to meet all of their needs and will be supported by Armstrong for many years to come.

Click this link to download the PDF version of this steam injection humidifier application note.

Hygienic Sight Flow Indicators for Pharmaceutical, Bio-pharmaceutical, and Food Processing

Hygienic Sight Flow Indicator

Jacoby-Tarbox, a division of Clark Reliance, manufactures a complete line of tubular and bulls-eye sight flow indicators manufactured specifically for pharmaceutical, bio-pharmaceutical, food, and other processing systems demanding cleanliness and maximum hygienic conditions.

Their tubular glass design allows full 360° view of the cylinder and they achieve controlled intrusion meeting ASME-BPE’s strictest requirements by employing:

• ASME BPE dimensions and Design Principles
• Precision-Bore borosilicate glass 
• Tightly tolerance EHEDG inspired O-ring capture

Watch the video below for a more detailed understanding. You can download a brochure about these hygienic sight flow indicators here.

For more information, contact Mead O'Brien at http://www.meadobrien.com or call (800) 892-2769.

Hygienic Sight Flow Indicators from Mead O'Brien, Inc.

HART Communication Protocol - Process Instrumentation

Process instrument with HART protocol (Foxboro)

The Highway Addressable Remote Transducer Protocol, also known as HART, is a communications protocol which ranks high in popularity among industry standards for process measurement and control connectivity. HART combines analog and digital technology to function as an automation protocol. A primary reason for the primacy of HART in the process control industry is the fact that it functions in tandem with the long standing and ubiquitous process industry standard 4-20 mA current loops. The 4-20 mA loops are simple in both construction and functionality, and the HART protocol couples with their technology to maintain communication between controllers and industry devices. PID controllers, SCADA systems, and programmable logic controllers all utilize HART in conjunction with 4-20 mA loops.

HART instruments have the capacity to perform in two main modes of operation: point to point, also known as analog/digital mode, and multi-drop mode. The point to point mode joins digital signals with the aforementioned 4-20 mA current loop in order to serve as signal protocols between the controller and a specific measuring instrument. The polling address of the instrument in question is designated with the number "0". A signal specified by the user is designated as the 4-20 mA signal, and then other signals are overlaid on the 4-20 mA signal. A common example is an indication of pressure being sent as a 4-20 mA signal to represent a range of pressures; temperature, another common process control variable, can also be sent digitally using the same wires. In point to point, HART’s digital instrumentation functions as a sort of digital current loop interface, allowing for use over moderate distances.

HART in multi-drop mode differs from point to point. In multi-drop mode, the analog loop current is given a fixed designation of 4 mA and multiple instruments can participate in a single signal loop. Each one of the instruments participating in the signal loop need to have their own unique address.

Since the HART protocol is a standardized process control industry technology, each specific manufacturer using HART is assigned a unique identification number. This allows for devices participating in the HART protocol to be easily identified upon first interaction with the protocol. Thanks to the open protocol nature, HART has experienced successive revisions in order to enhance the performance and capabilities of the system relating to process control. The standardization of “smart” implementation, along with the ability to function with the legacy 4-20 mA technology and consistent development, has made HART a useful and popular component of the process measurement and control industry framework.

Have a question about HART? Contact Mead O'Brien by visiting this link, or call
(800) 892-2769.

The Basics of Process Control Instrument Calibration

Calibration is an essential part of keeping process measurement instrumentation delivering reliable and actionable information. All instruments utilized in process control are dependent on variables which translate from input to output. Calibration ensures the instrument is properly detecting and processing the input so that the output accurately represents a process condition. Typically, calibration involves the technician simulating an environmental condition and applying it to the measurement instrument. An input with a known quantity is introduced to the instrument, at which point the technician observes how the instrument responds, comparing instrument output to the known input signal.

Even if instruments are designed to withstand harsh physical conditions and last for long periods of
time, routine calibration as defined by manufacturer, industry, and operator standards is necessary to periodically validate measurement performance. Information provided by measurement instruments is used for process control and decision making, so a difference between an instruments output signal and the actual process condition can impact process output or facility overall performance and safety.

In all cases, the operation of a measurement instrument should be referenced, or traceable, to a universally recognized and verified measurement standard. Maintaining the reference path between a field instrument and a recognized physical standard requires careful attention to detail and uncompromising adherence to procedure.

Instrument ranging is where a certain range of simulated input conditions are applied to an instrument and verifying that the relationship between input and output stays within a specified tolerance across the entire range of input values. Calibration and ranging differ in that calibration focuses more on whether or not the instrument is sensing the input variable accurately, whereas ranging focuses more on the instruments input and output. The difference is important to note because re-ranging and re-calibration are distinct procedures.

In order to calibrate an instrument correctly, a reference point is necessary. In some cases, the reference point can be produced by a portable instrument, allowing in-place calibration of a transmitter or sensor. In other cases, precisely manufactured or engineered standards exist that can be used for bench calibration. Documentation of each operation, verifying that proper procedure was followed and calibration values recorded, should be maintained on file for inspection.

As measurement instruments age, they are more susceptible to declination in stability. Any time maintenance is performed, calibration should be a required step since the calibration parameters are sourced from pre-set calibration data which allows for all the instruments in a system to function as a process control unit.

Typical calibration timetables vary depending on specifics related to equipment and use. Generally, calibration is performed at predetermined time intervals, with notable changes in instrument performance also being a reliable indicator for when an instrument may need a tune-up. A typical type of recalibration regarding the use of analog and smart instruments is the zero and span adjustment, where the zero and span values define the instruments specific range. Accuracy at specific input value points may also be included, if deemed significant.

The management of calibration and maintenance operations for process measurement instrumentation is a significant factor in facility and process operation. It can be performed with properly trained and equipped in-house personnel, or with the engagement of highly qualified subcontractors. Calibration operations can be a significant cost center, with benefits accruing from increases in efficiency gained through the use of better calibration instrumentation that reduces task time.

A Very Unique "No Straight Run Required" Flowmeter

VERIS Accelabar Detail

The VERIS Accelabar® is a unique flow meter that combines two differential pressure technologies to produce performance never before attainable in a single flow meter.

The VERIS Accelabar® is capable of measuring gases, liquids, and steam at previously unattainable flow rate turndowns—with no straight run requirements.

No Straight Run Required

The VERIS Accelabar® can be used in extremely limited straight run piping configurations. All necessary straight run is integral to the meter. The stabilization and linearization of the velocity profile within the throat of the nozzle eliminates the need for any upstream or downstream pipe runs.

Read the document below for more information or download the VERIS Accelabar® PDF from Mead O'Brien's website here.

VERIS Accelabar Flow Meter from Mead O'Brien, Inc.

Mead O'Brien: Experts in Valves, Valve Automation, Steam & Hot Water Systems, Process Instruments

Mead O’Brien specializes in valves & valve automation, steam & hot water products and systems, instrumentation products, skid designs, field services, surveys, assessments, and consulting.

Product Focus:

• Valves, valve automation and control
• Steam and hot water products and systems
• Instrumentation and controls

For more information, visit http://www.meadobrien.com or call  (800) 892-2769.

Please pardon our little shameless self-promotion. Thanks for watching this short video highlighting Mead O'Brien products.

Industrial Valve Actuator Basics

Electric actuator (Limitorque)

Actuators are devices which supply the force and motion to open and close valves. They can be manually, pneumatically, hydraulically, or electrically operated. In common industrial usage, the term actuator generally refers to a device which employs a non-human power source and can respond to a controlling signal. Handles and wheels, technically manual actuators, are not usually referred to as actuators. They do not provide the automation component characteristic of powered units.

The primary function of a valve actuator is to set and hold the valve position in response to a process control signal. Actuator operation is related to the valve on which it is installed, not the process regulated by the valve. Thus a general purpose actuator may be used across a broad range of applications.

Pneumatic actuator (Metso Neles)

In a control loop, the controller has an input signal parameter, registered from the process, and compares it to a desired setpoint parameter. The controller adjusts its output to eliminate the difference between the process setpoint and process measured condition. The output signal then drives some control element, in this case the actuator, so that the error between setpoint and actual conditions is reduced. The output signal from the controller serves as the input signal to the actuator, resulting in a repositioning of the valve trim to increase or decrease the fluid flow through the valve.

An actuator must provide sufficient force to open and close its companion valve. The size or power of the actuator must match the operating and torque requirements of the companion valve. After an evaluation is done for the specific application, it may be found that other things must be accommodated by the actuator, such as dynamic fluid properties of the process or the seating and unseating properties of the valve. It is important that each specific application be evaluated to develop a carefully matched valve and actuator for the process.

Hydraulic and electric actuators are readily available in multi-turn and quarter-turn configurations. Pneumatic actuators are generally one of two types applied to quarter-turn valves: scotch-yoke and rack and pinion. A third type of pneumatic actuator, the vane actuator, is also available.

For converting input power into torque, electric actuators use motors and gear boxes while pneumatic actuators use air cylinders. Depending on torque and force required by the valve, the motor horsepower, gearing, and size of pneumatic cylinder may change.

Linear pneumatic actuator (Neles)

There are almost countless valve actuator variants available in the industrial marketplace. Many are tailored for very narrow application ranges, while others are more generally applied. Special designs can offer more complex operating characteristics. Ultimately, when applying actuators to any type of device, consultation with an application specialist is recommended to help establish and attain proper performance, safety and cost goals, as well as evaluation and matching of the proper actuator to the valve operation requirements. Share your fluid process control requirements with a specialist in valve automation, combining your own process knowledge and experience with their product application expertise to develop effective solutions.