Increased Cycle Count Improves Operational Efficiency in Slurry Ore Mining Operations

Challenge

Long distance slurry pipelines for moving mineral concentrates over various elevations and long distances is often more economical than trucking or rail due to topography constraints and environmental concerns. To capitalize on these investments, the pipe sizes are maximized. Therefore, large-bore dependable valves are vital to the success of the slurry pipelines.

Under the same process conditions,
the competitor’s valve
underperformed and required
frequent maintenance due to erosion.

Three months after the main choke and choke loop press letdown stations were commissioned at a large copper-gold-molybdenum mining operation, ongoing repairs were required for all eight competitor valves. Valves in this position were expected to perform for at least 180 cycles without repair. These failures and leakage problems were caused by the valves’ integral seat design, which form a gap between the ball and seat allowing particles to enter the sealing area in the reverse pressure. This problem cost this customer an average of $800,000 to $1M per year in maintenance repairs.

Solution

Even with MOGAS’ 40-year history of successfully engineering large valves for the slurry transport market, MOGAS proposed to lease a test valve to be placed alongside a series of competitor valves.
In January 2013, a 36-inch, ASME 300 Class model CST-1 valve was installed in the  first loop of the control station. In this model’s proven bi-directional seat design, the seat maintains 100% contact with the ball in both normal and reverse pressures. This prevents build-up behind the downstream seat and ensures evacuation of solids around upstream seat during cycling.

Results

After one year the MOGAS
valve performed 818 successful
cycles—over four times the
cycle count required in this application.

One year later during decommission, the MOGAS valve was inspected. It had performed 818 cycles; far more than the 180 cycle count required in this application. The MOGAS valve was then removed and installed outside the loop, in the main choke station replacing the competitor valve, where it further performed 215 cycles for the next two years.

After three years of continuous operation, the MOGAS valve had successfully performed 1033 cycles. On inspection, the ball and seat were in good repair, so only the gasket and packing box were replaced and the valve was put back in to service.

Download the PDF of this case study from the PSI website here.

For more information, contact Piping Specialties, Inc. by calling 800-223-1468 or visit https://psi-team.com.

Reprinted with permission from MOGAS.

The Important Role of Valve Actuators

Actuator being positioned on large ball valve.
(Piping Specialties)

Valves are essential to modern industry. The prevalence of valves in engineering, process control, and manufacturing across the world is astounding, and each valve application requires it's own performance standard. Product safety, quality, and consistency is dependent on the proper selection of valves, whether ball, butterfly, gate or globe. Along with proper selection of the valve type, selecting the proper valve operator is critical for controlling the process, assuring quality, and protecting equipment and personnel.

Actuators are powered mechanisms that position valves between open and closed states; the actuators are controllable either by manual operators, or as part of an automated system where the actuator responds to a remote control signal. The valve actuator is as important to the valve, as the valve is to the industry in which it functions.

Thanks to actuators, multiple valves can be controlled in a process system in a coordinated fashion; imagine if, in a large industrial environment, engineers had to physically adjust every valve via a hand wheel or lever! It is completely impractical from a logistical and economic perspective. Actuators enable automation to be applied to valve operation throughout the facility.

Valve actuators serve as the interface between the control intelligence and the physical movement of the valve. The most obvious advantage of valve automation is risk mitigation, where, as long as the system is functioning correctly, critical calamities in either environmental conditions or to a facility can be pre-empted and quickly prevented.

Rack and pinion actuators.
(Flo-Tite)

Regardless of its power source, be it electricity, hydraulic fluid, air pressure, or other, all valve actuators share a singular purpose; to produce linear or rotary motion under the command of a control source. Depending on the design and settings of the actuator, valves can be closed, fully open, or somewhere in-between. Modern actuation technology allows for remote indication and control of valve position, as well as other diagnostic and operational information.

Pneumatic actuators utilize air pressure as the motive force which changes the position of a valve. Hydraulic actuators depend on non-compressible liquids under pressure to provide the motive force. Electric actuators, either motor driven or solenoid operated, rely on electric power to change valve position.

As automation continues to advance throughout every industry, manual valve operation makes less and less sense. Component integration, lower cost and universally accepted valve communications systems are becoming the norm. Simple, seldomly operated, basic valves are now outfitted with inexpensive automation packages that allow them to be monitored as part of the entire process control system.

Automated valves ready for shipment.

Thanks to their versatility, reliability, and technological advances, valve actuators provide safe and repeatable operation in critical processes all over the world.  Just as industries are the backbones of societies, valves are key building blocks to industrial processes, with actuators ensuring both safe and precise operation.

For information on valve automation, contact Piping Specialties by calling 800-223-1468 or by visting https://psi-team.com.

Conval Clampseal Valve Chamber REPACKING Instructions

Bonnet Chamber REPACKING instructions for Conval Clampseal valve.

Conval Clampseal® Valves are much easier to renew than anything else on the market. This video is fourth in a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468

Conval Clampseal Valve Chamber Unpacking Instructions

Bonnet chamber unpacking instructions for Conval Clampseal valve.

Conval Clampseal® Valves are much easier to renew than anything else on the market. This video is third in a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468

Industrial Process Refractometers

Process refractometer
(K-Patents)

The ultimate focus of industrial refractometry is to describe the percentage of certain compounds in a final product. Refractometry, a combination of physics, materials, and chemistry, is the process which measures the composition of known substances by means of calculating their respective refractive indexes (RI). RIs are evaluated via a refractometer, a device which measures the curve, or refraction, resulting when the wavelength of light moves from the air into and through a tested substance. The unitless number given by the refractometer, usually between 1.3000 and 1.7000, is the RI. The composition of substances is then determined when the RI is compared to a standard curve specific to the material of the substance.

Common examples of industrial refractometry uses are measuring the salinity of water to determine drinkability; calculating the dissolved solids in liquor processing in pulp and paper production;  figuring beverages’ ratios of sugar content; and understanding the hydrocarbon content of motor fuels. Regarding pulp and paper, refractometry scrutinizes content of compounds in black and green liquor processing. Regarding food, refractometry has the ability to measure the glucose in fruit during the fermentation process. Because of this, those in food services know when fruit is at peak ripeness and, in turn, also understand the most advantageous point in the fruit’s “lifetime” to put it on the market.


Equipment manufacturers have developed numerous refractometer configurations tailored to specific use and application. Each has a set of features making it the proper choice for its intended application. Product specialists can be invaluable sources of information and assistance to potential refractometer users seeking to match the best equipment to their application or process.

Don't Overlook the Importance of Scheduled Calibration for Your Plant's Process Instrumentation

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 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.

Conval Clampseal Valve Inspection Instructions

Inspection of the Conval Clampseal valve.

Conval Clampseal® Valves are much easier to renew than anything else on the market. This video is second of a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468