Mogas Ball Valve Mate Lap Seal Demo

This video 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.

CTi Controltech
https://cti-ct.com
925-208-4250

Industrial Ball Valve Basics

Specialized ball valve (PBM)

A ball valve is a rotational motion valve that uses a ball-shaped disk to stop or start fluid flow. The ball, performs the same function as the disk in the globe valve. When the valve handle is turned to open the valve, the ball rotates to a point where the hole through the ball is in line with the valve body inlet and outlet. When the valve is shut, the ball is rotated so that the hole is perpendicular to the flow openings of the valve body and the flow is stopped.

Most ball valve actuators are of the quick-acting type, which require a 90° turn of the valve handle to operate the valve. Other ball valve actuators are planetary gear-operated. This type of gearing allows the use of a relatively small handwheel and operating force to operate a fairly large valve.

MOGAS’s SC-3PC isolation ball valve in closed position.

Some ball valves have been developed with a spherical surface coated plug that is off to one side in the open position and rotates into the flow passage until it blocks the flow path completely. Seating is accomplished by the eccentric movement of the plug. The valve requires no lubrication and can be used for throttling service.

Advantages

MOGAS’s SC-3PC isolation ball valve in open position.

A ball valve is generally the least expensive of any valve configuration and has low maintenance costs. In addition to quick, quarter turn on-off operation, ball valves are compact, require no lubrication, and give tight sealing with low torque.

Disadvantages 

Conventional ball valves have relatively poor throttling characteristics. In a throttling position, the partially exposed seat rapidly erodes because of the impingement of high velocity flow. There are exceptions though, and ball valves can be used as control valves when modification to characterize the flow port are taken.

Port Patterns

Ball valves are available in the venturi, reduced, and full port pattern. The full port pattern has a ball with a bore equal to the inside diameter of the pipe.

Valve Materials 

Balls are usually metallic in metallic bodies with trim (seats) produced from elastomeric (elastic materials resembling rubber) materials. Plastic construction is also available.

The resilient seats for ball valves are made from various elastomeric material. The most common seat materials are teflon (TFE), filled TFE, Nylon, Buna-N, Neoprene, and combinations of these materials. Because of the elastomeric materials, these valves cannot be used at elevated temperatures. Care must be used in the selection of the seat material to ensure that it is compatible with the materials being handled by the valve.

Ball Valve Stem Design 

The stem in a ball valve is not fastened to the ball. It normally has a rectangular portion at the ball end which fits into a slot cut into the ball. The enlargement permits rotation of the ball as the stem is turned.

Ball Valve Bonnet Design 

A bonnet cap fastens to the body, which holds the stem assembly and ball in place. Adjustment of the bonnet cap permits compression of the packing, which supplies the stem seal. Packing for ball valve stems is usually in the configuration of die-formed packing rings normally of TFE, TFE-filled, or TFE-impregnated material. Some ball valve stems are sealed by means of O-rings rather than packing.

Ball Valve Position 

Some ball valves are equipped with stops that permit only 90° rotation. Others do not have stops and may be rotated 360°. With or without stops, a 90° rotation is all that is required for closing or opening a ball valve.

The handle indicates valve ball position. When the handle lies along the axis of the valve, the valve is open. When the handle lies 90° across the axis of the valve, the valve is closed. Some ball valve stems have a groove cut in the top face of the stem that shows the flowpath through the ball. Observation of the groove position indicates the position of the port through the ball. This feature is particularly advantageous on multiport ball valves.


For more information about any style industrial valve, contact CTi Controltech at 925-208-4250 or visit http://www.cti-ct.com.

MOGAS iRSVP Power Industry Valve Designation and Markings

MOGAS iRSVP vent
dran valve.

The MOGAS iRSVP Series is a family of isolation valves used for vents and drains in power applications. The iRSVP valve designed to handle high temperatures, high pressures, high cycling, thermal shock and abrasive media found in the power industry.

Applications for the MOGAS iRSVP

• Boiler drains
• Feedwater drains
• Steam drum vents
• Isolation valve for bypass lines
• Economizer header drains

The following video is a tutorial on how to understand the iRSPV valve markings and designation system.

CTi Controltech
https://cti-ct.com
925-208-4250

Increased cycle count improves operational efficiency in slurry ore mining operations

Slurry pipeline.

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.

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

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

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

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

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.

Advantages to installing a MOGAS valve:

• No downtime due to increased cycle time and continuous operation 
• No repair or maintenance of ball and seat
• Increased cycle count and greater revenue

For more information, contact CTi Controltech by calling 925-208-4250 or visit https://cti-ct.com.

Reprinted with permission from MOGAS.

Specialized Valve Trim Controls Flow and Pressure Drop

Fluid process control operations can entail fluid velocities, pressures, or other characteristics that can prove challenging on a number of levels, not the least of which is flow control. Valve manufacturers have developed a wide array of specialized designs and configurations to provide flow control while mitigating or eliminating some undesirable effects associated with restricting fluid flow.

Inherent in the restriction of flow is the possibility of creating or increasing some generally undesirable conditions in the pipe.

• Velocity
• Noise
• Vibration
• Erosion
• Cavitation

Depending upon the process conditions, any of these elements could have a decidedly negative impact upon process performance, workplace environment, or system longevity. The video provides an example of how one manufacturer of severe service ball valves, Mogas, modifies their design to address these potentially negative aspects while providing accurate flow control. By adding elements to the outlet side of a ball valve, an entirely different operating profile is achieved. Watch the video for all the details, as it is well produced and illustrated.

Share your fluid process control challenges with experienced application specialists. Combine your process expertise with their product application knowledge to produce effective solutions.

Severe Service Ball Valves Meet Toughest Application Challenges

Severe Service Ball Valve Section View
Courtesy Mogas Industries

Industrial process control, as a field of endeavor, can expose an engineer to instances where their design input can have very significant impact on the financial prospects of their employer, even the safety and well being of the public residing near company facilities. "Getting things right the first time" is much more than a motivating slogan on a poster tacked to the wall in the corridor outside the engineering department. It is what our society demands of engineers. Fortunately, there are engineers that embrace the role of making sure things go as planned. They work as process engineers and also as designers of the componentry and equipment used to implement complex and potentially dangerous processes.

I have written about the positive and potentially not so positive attributes of ball valves for industrial process control applications. In that recent blog article, I mentioned that ...

"There may be particular ball valve variants that overcome potential shortcomings listed in this article".

Ball valves designed for severe service are an example of a manufacturer specifically designing ball valves to not only overcome some potential shortcomings of the valve type, but to extend the performance ratings into areas that accommodate some of the most demanding applications in the process control field.

What constitutes severe service?

• Extreme temperatures
• High pressures
• Abrasive particulates
• Acidic products
• Heavy solids build up
• Critical plant safety
• Large pressure differentials
• Velocity control
• Noise control

Extended or enhanced features of severe service ball valves include:

• Floating or trunnion mounted ball design with straight through bore path that protects the sealing surfaces.
• Wide seat sealing surface with matched ball and seat sets that provide total sealing contact for reliable isolation. The greater sealing contact area withstands minor scratches and abrasions.
• Independent replaceable seats to minimize repair and maintenance costs.
• Pressure energized sealing, with seat springs that maintain a constant sealing contact between the ball and seats. Metal seats wipe the ball sealing surface clean during every operation.
• Blowout proof one piece oversized stem design meets stringent industrial safety standards and withstands maximum working pressures and extreme service torques.
• Dual-guided stem design employs pressure energized inner stem seals as a thrust bearing and lower stem guide. The valve stem bushing serves as the upper stem guide to eliminate lateral movement of the stem and prevent media migration and fugitive emissions.
• Greater body wall thickness, with forged body and end connections for longest service life.
• A heavy duty operator mounting flange, to provide structural support for the valve operator, is machined after attachment to assure precise stem alignment.

Application specific features, such as seat designs, live loaded packing, body gaskets, coatings, liners, purge ports, end connections, and special materials are also available to customize these severe service valves to meet extreme application requirements. The presentation below provides schematic and illustrated examples where severe service valves are applied and provides additional detail about the special features incorporated in the design of severe service ball valves. For all your control or isolation valve projects, whether in the conceptual, planning or implementation stage, consult a valve specialist. Merge your grasp of the process and its requirements with the product knowledge and application experience of a specialist and produce a solidly positive project outcome. 

Severe Service Control & Isolation Valves in the Refining Industry from CTi Controltech

Ball Valves Used in Continued Catalyst Regeneration

Severe service ball valve
(courtesy of MOGAS)

Control of pressure within the platforming process affects the reformer yields, reactor temperature requirements and catalyst stability. Critical to the stabilization of the entire process are the lockhopper isolation, catalyst addition, reactor isolation and vent valves.

Safely Handling Hydrogen to Eliminate Hazardous Fires

The potential for hydrogen fires caused by external body or stem leaks is a significant concern. The continuous scratching of catalyst fines to any exposed seats or plugs could eventually allow dangerous leak-through-to-atmosphere resulting in H2 fires. Specify metal-seated, severe service ball valves that do not expose critical sealing components to the damaging effects of catalysts and provide the self-wiping ball and seat configuration that will clean away any built-up debris.

A catalytic reformer unit
in a petroleum refinery
(courtesy of Wikipedia)

Eliminating Catalyst & Dust Build-up

As the catalyst breaks down, harmful dust is produced. If catalyst dust migrates into the packing chamber of the valve, it can erode the stem packing, causing an external leak. A rising, rotational stem action can create areas for this build-up. With a quarter-turn, non-rising stem found in ball valves, this problem is eliminated.

Dependable Cycling Prevents Interruptions

A CCR unit is a timed process. Valves are expected to open and close at certain times to allow or stop the flow of catalyst. If a valve fails to operate, the process cannot perform and locks up. Additionally, if a valve is leaking enough to affect the pressure on the next lockhopper, the unit controls will not allow the process to move on to the next step. Quick, quarter-turn operation of severe service ball valves is the best solution for this situation.

Maintaining Design Integrity During Thermal Expansion

If the operating temperatures are elevated, or an upset in the process occurs, thermal expansion of valve components can cause concern. Carefully consider the material and coating selections, combined with the engineered geometry allowances of the ball valve, and ensure reliable and adequate protection against extreme heat variations.

As with any engineered product, it is always suggested you call in an applications expert before you specify, purchase, or install such critical service ball valves.

High-integrity Pressure Protection System (HIPPS) Valves

A HIPPS (high-integrity pressure protection system) is a category of "instrumented system" designed to prevent an over-pressurization condition at a process plant.

For oil, gas and chemical producers, loss of containment is a critical matter.  Over-pressure on a tank, vessel or pipeline can potentially cause explosive, flammable, toxic or hazardous chemicals to be released causing possible loss of life or adverse effects on the environment. Loss of containment can also have huge negative effects on the plants bottom line.

HIPPS will shut off the source of the high pressure before the design pressure of the system is exceeded, as opposed to a relief system which will open an alternative outlet for the fluids in the system once a set pressure is exceeded. A relief system attempts to remove any excess inflow of fluids for safe disposal, where a HIPPS is designed to stop the inflow of excess fluids and containing them in the system.  Conventional relief systems are increasingly frowned upon because they typically vent, flare or discharge hazardous or toxic fluids in to the environment.

HIPPS valves are used as the final part of an instrumented system intended to prevent an unacceptably high pressure occurring in downstream equipment. They are always arranged to fail closed and spring/hydraulic actuators are usually the only practical alternative for operation.

You can see a full application note on HIPPS relating to valves and ancillary systems here. 

Unique Design Rotary Ball Control Valve Provides Superior Control

This rotary ball control valve video (courtesy of MOGAS) provides an informative look at the flow conditions inside a valve designed with a tortuous flow path and specialized characterization.

The Flexstream rotary control valve uses a standard ball valve body with a very specialized ball. As the ball opens, the video shows the tortuous path. The design allows for volumetric expansion when controlling gas. Velocity, noise and cavitation are controlled by repeated 90 degree turns in the flow path. This design is excellent for applications that require wide range-ability.