By Robert M. Donnelly — Vice President of Business Development, Flo-Tite Valves & Controls
Ball valve suppliers have developed a wide variety of designs and components to meet these evolving automated applications and the ever present search for more environmentally sensitive and cost effective solutions. This piece will highlight some of these key engineered solutions.
For many years the popular reduced port flanged end ball valve was a one piece design which was a good idea because this design had no body joint. However, this design was very difficult to repair. Larger sizes would have to be sent out to valve repair shops to change out the seats requiring the process the valve was in to be shut down usually for weeks, or if a quick replacement was needed a spare valve would have to be kept in stock. Plus, these repairs and any upgrades e.g. more expensive or metal seats were costly. Two piece reduced port body designs can eliminate a lot of these costly repair issues.
In another situation media was being trapped in the interior of ball valves in the closed position. To solve this dangerous situation an Open-Port safer design was developed to eliminate any pressure build up due to thermal expansion in standard ball valves. This design also allows for an easier flushing action when the ball is in its intermediate position.
This unique ball valve design also allows for the use of ball valves in applications never before possible. These open-port ball valves can also be supplied with full-body cavity fillers. Cavity fillers fill the void normally found behind the ball and the valve body in conventionally designed ball valves. This assures that no media is allowed to become trapped above, below, or around the valve ball or the body cavity. Cavity fillers also prevent freezing or seizing, while also reducing the possibility of cross contamination of media.
Historically, ball valves had to be disassembled before being welded into a process control application because the heat of the welding process would impair the valve seat materials. This is a time consuming and costly process.
Additionally, for automated valve packages, the valve automation components also have to be disassembled voiding the manufacturer’s performance warranty, as well as the integrity of the testing of the interaction of the total automation package performed prior to delivery by the supplier. This often has caused quality control issues and disputes due to improper reassembly.
There are designs such as a socket or butt well ball valve with extended end caps with heat sink rings that have a series of radiator-type grooves cast into the outside diameter. This creates an increased surface area that allows for heat to dissipate during the welding process thus protecting the valve seat materials from any damaging heat transfer.
This unique design allows for three piece soft-seated valves to be welded into any piping system without disassembly or special welding procedures. It also protects the integrity of automated valves packages because no disassembly is necessary.
Besides the obvious time and cost savings, weld-in-place valves represent a safer installation with reduced liability for both manual and automated ball valves.
Flanged/Wafer Full Bore Ball Valves
Wafer style ball valves have been designed for applications where space and weight are major considerations. Wafer style valves offer a low profile design that is also ideal for control valve applications.
The Uni-body construction eliminates the possibility of body seal leaks and also adds strength to the pipeline while weighing about 30% less than conventional full port valves. The pocketless design is also available with full PTFE cavity fillers. The unique low-torque design of wafer type ball valves has precision dimensions with very tight tolerances for exact compression of ball seats. The low-torque stem design with a blow-out proof stem shoulder has a 45 degree bell shaped slope with a V-Ring live loaded stem packing.
With a torque of approximately 20% lower than conventional full port valves the wafer style ball valve allows for the use of smaller actuators and mounting kits, providing an overall lower profile. This combination makes for a very competitive cost effective automation package for a variety of applications.
Media Containment Devices
In any industry that uses ball valves in their process control applications, one of the primary concerns is the potential leak path through the valve stem seals caused by repeated cycling of valves over extended periods of time.
Some media containment device is a live-loaded design using Belleville washers which automatically compensates for temperature and pressure fluctuations thus maintaining a leak proof seal that extends the life of the valve. The device seals off any potential valve stem leaks in line and under pressure.
Additionally, the added height helps distance the valve operator from any dangerously high temperature media.
Monitoring and sensing devices can also be easily adapted to the media containment device for even more leak protection assurance.
Considering the potential of a plant shutdown and related costs due to fugitive emissions, the possibility of an EPA fine, lawsuits, negative public relations, and higher insurance premiums, the media containment device is certainly well worth its modest cost.
Actuation and Controls
Given that most ball valves in process control application are automated, the automation components have also become more important and more critical.
Mounting kits historically had to be provided by mounting kit manufacturers, which were expensive with long lead times. These day’s inexpensive, simpler and innovative valve automation hardware, and stem extensions are available.
Prefabricated cost effective mounting kits with standard ISO patterns and couplers are available off the shelf so that any industrial valve distributor can automate valves with simple tools. Likewise, similar bracketry is available for mounting limit switches, positioners, and other valve automation components.
One stop shop valve automation suppliers also offer a collection of pneumatic and electric actuators for every process control application. These range from the standard rack and pinion pneumatic design to 4 piston, cylinder type, spring diaphragm styles, and heavy duty Scotch-Yoke versions.
Pneumatic actuators are available in standard aluminum, and stainless steel for highly corrosive environments. A variety of special coatings are also available for other applications. Filter regulators, solenoids, position indicators, and a variety of speed controls are also available.
The value of one-stop suppliers of manual and automated valves is the consolidation of all of the valving needed for process control applications is available from one source. This eliminates the historical time consuming and costly process of getting quotes from a variety of suppliers of one component or another, associated freight costs, and delivery times.
As the internet has evolved so has automated valve sourcing, and along with it the evolution of valve configurators. A configurator is an online platform that allows for the configuration of valves and valve automation packages without any human involvement.
Sophisticated configurators have photo’s, illustrations, and technical information on specific valves and all of the components required for different valve automation configurations; including all related prices. The configurator has the capability of developing and providing a complete quote with all supporting documentation and configuration for the valving for a specific process control application without any human involvement.
Additionally, configurators store all the information on a specific order for every customer so that if additional similar requirements are required they can be ordered without having to be requoted. Likewise, online modifications can be made to historical orders.
For young engineers who have grown up on the internet this has become their preferred way of doing business.
In summary, this is a compilation of some of the latest developments in valve technology and how they can be utilized for more effective and less costly manufacturing effectiveness.
ABOUT THE AUTHOR
Bob Donnelly is the Vice President of Business Development for Flo-Tite Valves and Controls. He has over 30 experience years in the valve industry and was a pioneer in the introduction of the concept of valve automation.