Flowserve ValveSight Diagnostic Solution for Control Valves

The video shared this week, from Flowserve, provides an overview of their ValveSight real time online diagnostic solution for use with control valves and associated actuators, positioners and controls. ValveSight enables operators to keep valves in service longer by detecting potential failures before they occur. The system provides a deep level of monitoring and diagnostic functions which are described in the video. Reducing unplanned downtime is a common goal among all facilities and plant operators. Check out the short video, and share your questions about the system with an application specialist.

Rotork Instruments Brands Join ISI Technical Group Product Portfolio

Midland brand air line filter regulator
Courtesy Rotork Instruments

ISI Tech Group now handles a large complement of the Rotork Instruments brand family throughout the Florida and South Georgia area. A number of well recognized brand names have been incorporated into the Rotork Instruments group of products in recent years and ISI now handles four of them.

Midland is a specialist manufacturer of stainless steel large flow air service equipment. Purpose specific, manufactured solutions for filtration and regulation of compressed air and gases is the specialty of the brand. Products include filters and regulators, poppet valves, spool valves, air pressure switches, flow regulators, and a host of specialized ancillaries that fill out a complete system installation.

The Fairchild brand, which has been on the roster of ISI Tech Group products for some time, offers a wide selection of electro-pneumatic transducers, pressure regulators, pneumatic relays, volume boosters, filters and accessories for process machine tool, robotic and other industrial applications. Products are available with designs to suit all environments, including hazardous areas.

M&M industrial solenoid valves
Courtesy Rotork Instruments

M&M International is also a Rotork Instruments brand. M&M solenoid valves are manufactured with high quality materials and to rigorous standards to deliver durable performance and high reliability. Robust construction makes these valves well suited for industrial applications. A choice of seal materials provides wide fluid compatibility. Products include general purpose solenoid valves, air actuated piston valves, automatic drain valves, and accessory products

Block and bleed needle valve assembly
Courtesy Rotork Instruments

Bifold, another Rotork Instruments brand, manufactures medium pressure instrumentation ball valves, needle valves, fittings, manifolds, and relief valves for applications with pressure up to 20,000 psi.

This expanded product offering empowers the process measurement and control specialists at ISI Tech Group to better serve the diverse requirements of their customer base. Share your automation and process control challenges with experts, combining your own knowledge and experience with their product application expertise to develop effective solutions.

High Performance Butterfly Valves

Valdisk High Performance Double Offset Butterfly Valve
Courtesy Flowserve - Valtek

Industrial process control applications can present stringent and challenging performance requirements for the physical equipment and components that comprise the process chain. The valves employed in fluid based operations need to be resistant to the impact of extreme fluid conditions, requiring careful design and selection consideration to assure proper performance and safety levels are maintained in a predictable way.

Industrial valves intended for extreme applications are generally referred to as severe service or high performance valves. While there are plenty of published and accepted standards for industrial valves, one does not exist to precisely define what constitutes a severe service valve.

So, how do you know when to focus valve selection activities on severe service or high performance valves, as opposed to those rated for general purpose? There are a number of basic criteria that might point you in that direction:

• Extreme media or environmental temperature or pressure
• High pressure drop operation that may cause cavitation
• Rapid or extreme changes to inlet pressure
• Certain types or amounts of solids contained in the fluid
• Corrosive media

Certainly, any of these criteria might be found in an application serviceable by a general purpose valve, but their presence should be an indicator that a closer assessment of the fluid conditions and commensurate valve requirements is in order. The key element for a process stakeholder is to recognize when conditions are contemplated that can exceed the capabilities of a general purpose valve, leading to premature failure in control performance or catastrophic failure that produces an unsafe condition. Once the possibility of an extreme or challenging condition is identified, a careful analysis of the range of operating conditions will reveal the valve performance requirements.

There are numerous manufacturers of severe service or high performance valves, each with specialized product offerings focusing on a particular performance niche. Flowserve, under their Valtek brand, manufactures the Valdisk high performance butterfly valves ranging from NPS 2-52 and ASME class 150, 300, 600, 900, 1500 pressure ranges. The valve design is ideal for manual or automated actuation, installed with a manual hand gear, electric actuator, or a pneumatic actuator. Seats are available as soft or metal on this double offset butterfly valve that provides tight closure for bi-directional flow. Construction materials include carbon steel and stainless steel. A range of options and variants are available to customize the valve build to suit a replacement or new installation.

There is more information available about the Valtek high performance offering. You can always get more information and discuss your special requirements with a valve specialist. They have application experience and access to technical resources that can help with selecting the right valve components to meet your severe service and high performance applications.

Protecting Pressure Relief Valves and Safety Relief Valves

A rupture disc can provide PRV isolation

Safety and pressure relief valves are common elements of any pressurized system. Their general purpose is to stop system pressure from exceeding a preset value, preventing uncontrolled events that could result in damage to personnel, environment, or assets. Their operating principle and construction are comparatively simple and well understood.

Long term exposure of a relief valve to any number of media can result in corrosion, material buildup, or other conditions which may shorten the useful life of the valve, or worse, impair its proper operation. This excessive wear will increase the ongoing cost of maintaining or replacing a prematurely worn valve. One other aspect of relief valves can be the reduction in their seal integrity or force as the system pressure approaches the setpoint. This could possibly lead to fugitive emissions, an undesirable condition.

A reasonable solution is posed by Fike, globally recognized leader in fire, explosion, and overpressure protection. Isolating a relief or safety valve from the process media through the installation of a rupture disc upstream of the valve inlet will eliminate exposure of the costly valve to effects of the media. It is necessary to establish proper rating and selection for the rupture disc to avoid any impairment of the overall operation of the relief valve, but the selection criteria are not complex. A number of benefits can accrue with this concept.

• Avoid purchase of relief valves manufactured from exotic materials to accommodate exposure to corrosive media. Rupture disc provides isolation of the valve from the media.
• Eliminate fugitive emissions at the relief valve. Rupture discs, when properly installed, are leak free and bubble tight.
• Relief valve inventory can be evaluated for reduction.
• Longer valve life.
• Less downtime.

The additional cost for the rupture disc enhancement can have a reasonable payback period, with all factors considered. In any case, the rupture disc protection makes for a cleaner relief valve installation.

Rupture discs and holders are available in sizes and materials for most applications. Share your ideas with a product specialist, combining your process knowledge with their product application expertise to develop an effective solution.

Applying rupture discs for relief valve protection from Instrument Specialties, Inc.

Combating Cavitation in Industrial Process Control Valves

Cavitation in liquid processes produces bubbles which can
damage valves.

In process control valves, cavitation results from a rapid drop in pressure as liquid passes through the valve. It results in the formation of vapor spaces or bubbles within the valve cavity. When the bubbles move downstream into a larger cross-sectional area, velocity decreases and pressure increases. The higher pressure now surrounding the bubbles causes them to implode, producing shockwaves which propagate through the liquid. These shockwaves can cause metal fatigue and excessive wear on the internals of the valve. The collapsing bubbles also make a discernible sound with accompanying vibration. The cumulative effects of cavitation can cause rapid deterioration of a valve, resulting in reduced control function, frequent need for service, or premature failure.

There are ways to mitigate cavitation. Some involve changes in the process, others, incorporating a properly designed and selected valve with trim that reduces or prevents the conditions that cause cavitation. The paper below, authored by Flowserve, provides an in depth examination of the causes of cavitation, then continues with explanation of how their specialty valves are designed to overcome the conditions that promote it.

There are detailed illustrations showing the specific valve trim features that impede cavitation. Share your process control valve challenges with application experts, combining your process knowledge with their product application expertise to develop effective solutions.

Cavitation Control in Industrial Valves from Instrument Specialties, Inc.