Showing posts with label Mogas. Show all posts
Showing posts with label Mogas. Show all posts

Thursday, July 12, 2018

MOGAS Severe Service Ball Valve "Mate Lap" Seal Demonstration

The video below demonstrates the effectiveness of the MOGAS "Mate Lap" seal provided on MOGAS severe service ball valves.

MOGAS valves have outperformed others worldwide in some of the most severe service conditions, including: Extreme temperatures; High pressures; Abrasive particulates; Acidic products; Heavy solids build-up; Critical plant safety; Large pressure differentials; Velocity control; Noise control.

Tuesday, March 27, 2018

Increased Cycle Count Improves Operational Efficiency in Slurry Ore Mining Operations

slurry
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.

Slurry Ore Valve
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
Slurry Ore Valve
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.

Thursday, November 30, 2017

What Are Industrial Ball Valves?

Internal view of a ball valve
Internal view of a ball valve
(MOGAS)
Ball valves are defined by their body style, the five major styles being: Uni-body; 3-piece; split-body; top-entry; and welded body. They are further defined by the machined hole in their ball (also known as the port); the categories being "standard port" or "full port".

On a full port valve, the port is the same size as the pipeline, resulting in a better flow profile and no restriction or pressure drop. A full ported ball valve, with better flow coefficients, comes at a higher price. In many application they are necessary because a reduction in diameter, or the resulting change in flow, can be detrimental.

The reduction in a standard port valve is one pipe size smaller than the pipe connected to the valve, resulting in restricted flow and increased velocity through the valve.

2-piece and unibody ball valves
2-piece and unibody ball valves (Flo-Tite)
Standard port and full port valves are not usually recommended for throttling service due the a very
non-linear flow characteristic. Characterizing the port with a special shaped orifice can improve the valve linearity and provide good control. V-port ball valves incorporate a machined "V" in the seat around the outlet side of the valve. The "V" provides a more controllable flow pattern and is desirable when ball valves are used as control valves.

A cavity filled ball valve is used in applications where cleanliness or sanitary conditions exist. Any voids, gaps or spaces between the ball, seat and stem that allow bacteria or contaminates to accumulate are filled.  The proper cavity filler material is selected consistent with the process media, application and level of cleanliness required. Cavity fillers eliminate the spaces and voids where contaminants accumulate and provides easy "flushing" (cleaning) of the valve.

In a trunnion mounted ball valve, the valve stem is mechanically attached to the ball. Trunnion mounted valves are mostly used in applications on large diameter gas and oil pipelines and at high pressures.

Most ball valves however, are designed with a “floating ball” and not held mechanically in place by a trunnion. This allows the ball to be "pushed" slightly downstream and seal itself better against the seat. One advantage to this design is that a valve using a floating ball, and fitted with metal seats, can be used for "fire-safe" applications. This means that if the valve is subject to high temperatures, such as those presented in a fire, the "soft" part of the seat will melt away, and allow the ball to secure itself against the metal seat, and thus not allow material to pass and potentially feed the fire.

For best service life and optimum safety, please review your application with a qualified ball valve applications consultant prior to specifying an industrial ball valve.

Thursday, October 12, 2017

Mogas FlexStream: Rotary Control Technology for Severe Service Applications

Process plants have increased throughput causing operating pressures and flow rates to increase as well. Advanced production techniques demand better equipment and valve performance to handle these severe conditions. FlexStream rotary control technology is designed specifically for severe service conditions, to provide superior velocity control, variable characterization, exceptionally high rangeability, and precision modulation.

Mogas FlexStream
1) Diffusion element splits and aligns the flow.
2) The control element reduces the flow velocity.
Within a compact replaceable trim design, located downstream with a seat, FlexStream technology employs flow paths of different configurations to control flow and pressure drop. First the diffusion element splits and aligns the flow, then the control element reduces the flow velocity through a variable arrangement of torturous flow path. This allows precise pressure let down, and velocity control custom tailored to process conditions. These torturous flow paths consist of a series of right angle turns. Pressure is reduced by directing fluid flow through these right angles, which control kinetic energy and velocity. Pressure drop at each stage is evenly distributed, while the torturous path expands at each right angle to ensure velocities will not be increased. The larger the pressure drop, the more turns are required to control velocity.

For applications requiring high rangeability, ideal flow control is available by varying the combination of control area and open area, within the trim. The control area determines the amount of bore filled with multi-stage paths, and is used for higher pressure drop lower flow conditions. The open area determines the amount of unrestricted flow, and is used for lower pressure, drop higher flow conditions. This custom fill characterization can vary from 30 to 100 percent, depending on flow conditions, pressure drop, noise level, and outlet velocity required. Precise process and velocity control are achieved at every stage of valve opening, with exceptionally high rangeability in a single control valve.

For gas and steam applications, extreme noise and vibration are reduced or eliminated. The patented FlexStream technology expands upon the strengths of Mogas quarter turn ball valves to offer application-specific trim engineered for high delta-P applications, replaceable control element design, greater Cv per inch compared to the competition, and a smaller dimensional envelope in a traditional control valve.