Wednesday, August 31, 2016

Using a Valve Monitor for Tank Fill Control

Tank fill application
Tank fill application using a StoneL Axiom
Expeditor
to throttle flow.
Fill tanks and hoppers rapidly and accurately using the StoneL Axiom Expeditor valve monitor on a pneumatically operated valve.

You can set the Axiom Expeditor to partially close the valve to reduce flow as the full level approaches. You get fast, economical “topping off” of every batch with a single valve sized for high flow rates, which may be throttled back at the end of the fill cycle.


Simple operation and control system integration
  • Full open and closed cycling is performed by energizing and de-energizing the discrete 24 VDC output (DO) from the control system.
  • A preset intermediate position may be achieved by maintaining power from the discrete output (DO) and switching on the analog output (AO) at a preset level between 4 and 20 mA.
  • Intermediate control is achieved by maintaining power from the discrete output (DO) and energizing the control system’s analog output (AO). By changing the AO signal, the Axiom control output will toggle the solenoids to the desired position within ±4% of full scale.
  • The valve/actuator operates to the fail-safe position whenever the discrete output (DO) is de-energized.
Schematic for tank fill application
Schematic for tank fill application showing control inputs/outputs.
Watch this short video illustrating how the tank fill feature works.

Tuesday, August 30, 2016

BIST (Built-in-Self-Test) Features for Electronic Valve Actuators

Limitorque
Electric actuator (Limittorque)
Abstract

The development and implementation of safety related devices in plant systems is crucial for dependable operation, not to mention peace of mind. Safety and safe operation were once only high priorities for installations that involve hazardous environments. Expensive certification testing was, and still is, paramount to meeting the hazards of such environments, but a new level of plant-wide integrity is emerging — that of Safety Integrity Level (SIL) and SIS. SIL is a safety rating that can be derived by analyzing a system to determine the risk of a failure occurring and the severity of its consequences. Safety Instrumented Systems (SIS) are systems containing instrumentation or controls installed for the purpose of preventing or mitigating a failure either by emergency shut down (ESD) or diverting the hazard. New or replacement equipment must have the ability to be introduced into plant systems without jeopardizing either the SIL of the operation or negatively impacting the SIS.

Read the entire white paper below.

For more information visit this link or contact:

Mead O'Brien
www.meadobrien.com
(800) 892-2769

Tuesday, August 23, 2016

Understanding & Solving Heat Transfer Equipment Stall

heat transfer equipment
Heat transfer loop
Stall can most easily be defined as a condition in which heat transfer equipment is unable to drain condensate and becomes flooded due to insufficient system pressure.

Stall occurs primarily in heat transfer equipment where the steam pressure is modulated to obtain a desired output (i.e. product temperature). The pressure range of any such equipment ( coils, shell & tube, etc....) can be segmented into two (2) distinct operational modes, Operating and Stall.

Operating: In the upper section of the pressure range the operating pressure (OP) of the equipment is greater than the back pressure (BP) present at the discharge of the steam trap. Therefore a positive pressure differential across the trap exists allowing for condensate to flow from the equipment to the condensate return line.

Stall: In the lower section of the pressure range the operating pressure (OP) of the equipment is less than or equal to the back pressure (BP) present at the discharge of the steam trap. Therefore a negative or no pressure differential exists, this does not allow condensate to be discharged to the return line and the condensate begins to collect and flood the equipment.

You can read the entire Armstrong technical paper below.

Visit this link to download your own copy of Armstrong Fluid Handling: Understanding and Solving Equipment Stall.

Friday, August 12, 2016

Applying the ASCO 212 Composite Solenoid Valve for Reverse Osmosis Water Systems

ASCO Mead O'Brien Series 212
ASCO Series 212 Composite Solenoid Valves
for Reverse Osmosis Water Systems
Reverse osmosis (RO) is one of the most popular methods for effective water purification. It has been used for years to purify contaminated water, including converting brackish or seawater to drinking water.

Reverse osmosis is a process in which dissolved inorganic solids (such as salts) are removed from a solution (such as water). This is accomplished by pushing the water through a semi permeable membrane, which allows only the water to pass, but not the impurities or contaminates.

Reverse Osmosis can deliver bottled-water quality safety and taste by removing over 99% of dissolved minerals, chlorine and contaminants. Many leading bottled-water companies actually use large-scale RO to produce their water.

Reverse osmosis systems are found in several drinking water applications from restaurant, food and beverage equipment to grocery store produce misting.

The ASCO Series 212 solenoid valve is designed for these type systems. The valves come with NSF approvals for use in drinking water systems and also is design with unique “FasN” quick connection system. The valves are designed to handle 150 psi up to 180 deg. F. and has low wattage coils in both AC and DC.

See the video below for an illustration of where these valves are used in RO systems.

Tuesday, July 26, 2016

Foxboro Vortex Flow Meters

Foxboro vortex flow meterThe patented family of Foxboro vortex flowmeters has the high accuracy and rangeability of positive displacement and turbine flowmeters without the mechanical complexity and high cost. Maximum rangeability up to 100:1 is possible as compared to 3:1 for a nonlinear differential pressure producer (orifice plate).

Because these Flowmeters have no moving parts, they are very durable and reliable. This simplicity of design ensures low initial cost, low operating and maintenance costs, and therefore contributing to an overall low cost of ownership.



For more information, contact:

Mead O'Brien
(800) 892-2769

Friday, July 22, 2016

Traps for Sour Gas Service

Armstrong Series 300
Armstrong Series 300
What is “sour gas”? 

In the oil and gas industry, “sour gas” refers to natural gas that is contaminated with hydrogen sulfide (H2S or “sulfide”). “Sour crude,” similarly, is crude oil that contains hydrogen sulfide. These are naturally occurring conditions, but definitely not desirable. Aside from the environmental pollution problems with “high-sulfur” fuels, there are some serious corrosion problems that can affect many materials. Liquid drainers (drain traps) and strainers are the most common Armstrong products ordered for sour gas service. A few other products are sometimes specified, notably inverted bucket air traps. An inquiry may be accompanied by an extensive specification of H2S concentrations; there may be a line indicating “Sour Gas Service;” or may only be the note “NACE.” This is a reference to Standard MR0175-93 published by the National Association of Corrosion Engineers (NACE).

What is the problem? 

H2S under pressure permeates into the crystalline structure of the metal and strains the structure of the crystal. This reduces its ability to deform in a ductile manner. The net effect is to make the material brittle. In the presence of external stresses due to applied pressure or loads, or internal stresses due to cold working or welding, parts may fail by cracking without any warning. This process is called Sulfide Stress Cracking (SSC). SSC is affected by many parameters, including: · Composition, strength, heat treatment, and microstructure of the material; · Hydrogen ion concentration (pH) of the environment; · Hydrogen sulfide concentration and total pressure; · Total tensile stress; · Time and temperature. Choice of products and their limitations. Inverted bucket traps (primarily for air trap service) should be selected from the Series 300 traps. The bucket and mechanism (except valve and seat) will be annealed to eliminate the locked-in stresses from the stamping operations. The valve and seat will be made from Type 316 stainless, without additional heat treatment. Cast iron bucket weights are permitted, since they are not stressed in tension. Special bolting is required only if the sour environment is also outside the trap.

Download the Sour Gas Trap Selection Guide Here

Wednesday, July 20, 2016

Mead O'Brien VP Elevated to ISA Fellow

ISA Fellows 2016
ISA Fellows 2016
The International Society of Automation (www.isa.org) is a nonprofit professional association that sets the standard for those who apply engineering and technology to improve the management, safety, and cybersecurity of modern automation and control systems used across industry and critical infrastructure. It currently boasts 40,000 members worldwide.

Steve Huffman
Steve Huffman
Elevation to the distinguished grade of ISA Fellow is granted to Senior Members in recognition of their exceptional engineering scientific contributions to the field of automation.

Steve Huffman, VP of Sales and Marketing at Mead O'Brien will be one of the honorees at the 54th Annual ISA Honors & Awards Gala to be held on 24 September 2016 in Newport Beach, California.

Steve is being recognized for leading the effort to create the US Department of Labor’s Automation Competency Model for automation professionals.

Congratulations to Steve for this achievement and for his many years of service to the instrumentation and automation community.