All posts by SIS WEBADMIN

Setpoint Shares How Embedded Assets Support Reducing Downtime

Setpoint Shares How Embedded Assets Support Reducing Downtime

Providing high-quality, innovative solutions that reduce costly downtime for industrial plants via onsite mobile service units and necessary in-line repairs is the expertise of Setpoint Integrated Solutions. Setpoint understands industrial safety and delivers high-quality services, managing all projects with operational excellence… click here to read more.

Embedded asset support can reduce downtime for industrial plants

To learn how Setpoint Integrated Solutions Embedded Assets can support your industrial needs, please click here to request a meeting with our team.

PVI Holdings, Inc. acquired by MiddleGround Capital

PVI Holdings, Inc. acquired by MiddleGround Capital


PVI Holdings, Inc. acquired by MiddleGround Capital

Baton Rouge, LA (July 19, 2022) – MiddleGround Capital has acquired PVI Holdings, Inc. MiddleGround is an operationally-focused private equity firm that makes control investments in the North American middle market primarily focused on B2B industrial and specialty distribution companies.

Included in this transaction are Setpoint Integrated Solutions Inc., W&O Supply, Inc. and A-T Controls, Inc.

“It was a cultural fit from our first meeting, MiddleGround brings a unique style to private equity that has my team fired up about the future.” said Brad Bergeron, PVI CEO. “We value their operational expertise, passion for continuous improvement, and believe they are the perfect owner for PVI’s next phase of growth.

“We are extremely excited to partner with MiddleGround on the next step of our journey.” said Matt Bate, Setpoint President. “Setpoint’s focus on caring for and creating value for our people, our customers and the communities we serve will continue. Our partnership with MiddleGround will enhance and accelerate those efforts and create additional opportunities for growth.”



About Setpoint Integrated Solutions (and its subsidiaries)

Setpoint is the leader in the process control industry with nearly 700 dedicated employees supporting 12 facilities across the Gulf Coast. Setpoint’s portfolio includes industry-leading new and remanufactured valve and instrumentation lines serving multiple market segments along with best-in-class repair services.

For more information, please visit


About MiddleGround Capital

MiddleGround Capital is a private equity firm based in Lexington, KY with over $2.4 billion of assets under management. MiddleGround makes control equity investments in middle market B2B industrial and specialty distribution businesses. MiddleGround works with its portfolio companies to create value through a hands-on operational approach and partners with its management teams to support long-term growth strategies.

For more information, please visit:




Ben Davis, Vice President of Sales


Setpoint Integrated Solutions Acquires Valsource International

Setpoint Integrated Solutions Acquires Valsource International

Baton Rouge, LA (December 1, 2021) – Setpoint Integrated Solutions acquires Houston-based Valsource International in a customer-focused move, adding additional territory to Setpoint’s Gulf Coast footprint. Valsource International specializes in comprehensive control valve and pipeline repair services for maintenance, emergency and scheduled outage requirements.

“This acquisition demonstrates Setpoint’s commitment to being a leader in the process and flow control industry. Valsource International’s history of great customer service and specialization in comprehensive control valve and pipeline repair services enhances our portfolio for the Houston market,” said Matt Bate, President and CEO of Setpoint Integrated Solutions. I am excited to welcome the talented team from Valsource that will be joining the Setpoint family. 

Setpoint Integrated Solutions has more than 185 certified technicians spread over 11 facilities across the Gulf Coast, offering the best-in-class valve repair services and delivering process solutions for control, relief, and automated valve requirements, along with industrial equipment including liquid level measurement, pressure gauges, and more. 

“I’m proud of the business we’ve built, providing quality valve repair and remanufacturing services in the petrochemical industry to the Houston region,” said Chris Thibodaux, Owner of Valsource International. The secret to our success is the family culture of our team and their dedication to our customer base. We are excited to partner with Setpoint and take the next step in our journey.” 

About Setpoint Integrated Solutions
Setpoint Integrated Solutions is headquartered in Baton Rouge, La., and is a subsidiary of Pon Holdings B.V. of the Netherlands. Pon is an international trading and service organization with a workforce of 14,000 people spread over 450 locations in 32 countries.

For more information, please visit and

About Valsource International LLC.
Founded in 1998, Valsource International specializes in comprehensive repair and remanufacturing services for all control valve, pipeline valve, safety relief valve, and on-site field service needs.

Valsource is strategically located in the hub of Houston’s refining and petrochemical industry to best respond and accommodate the needs of  the customers.

Setpoint Integrated Solutions Announces Matt Bate as new President & CEO

Setpoint Integrated Solutions Announces Matt Bate as new President & CEO

Media Contact:
Fatima Mehr, Director of Marketing

Baton Rouge, LA (May 11, 2021) – Setpoint Integrated Solutions is pleased to announce that effective May 31, 2021, Matthew Bate, current Setpoint Chief Financial Officer, will be promoted to the role of President & Chief Executive Officer. Bate will succeed Jeff Birch, who will transition to Managing Director, President & Chief Executive Officer of fellow Pon Holdings organization, The Hiller Companies.

“The continuous improvement culture that we’ve created within Setpoint is fast-paced, consistently evolving, and embraces positive change,” Birch said. “As I reflect on the last few years of growth and success at Setpoint, I am incredibly proud of the many accomplishments of the organization and have the utmost confidence in Bate’s ability to lead the outstanding people and business of Setpoint.”


Bate is a graduate of Texas A&M, receiving both his Bachelor of Business Administration and Master of Science in Finance from the Mays School of Business. Prior to joining Setpoint as the Chief Financial Officer in 2018, Bate held various leadership roles at PWC,  Schlumberger, and Pon. Bate and his wife, Hayley, have two young children, Austin and Reese.


“On behalf of Setpoint, I want to thank Jeff for his leadership over the past 5 years.  Setpoint is extremely well  positioned for continued growth with strong OEM partnerships and established customer relationships, but most importantly, exceptional people throughout our organization.  We will continue to operate within our core operational priorities led by our total commitment to safety and quality and manage our business through data-driven analytics and digital investment,” Bate said. “Together with Setpoint’s leadership team and more than 700 employees, I’m confident we will continue to perform at the highest level for our customers.”

About Setpoint Integrated Solutions

Setpoint Integrated Solutions is the leader in the process control industry with 11 facilities across the Gulf Coast. Supporting the Power, Refining, and Chemical Industries with best in class valve repair services, delivering process solutions for control, relief, and automated valve requirements, along with industrial equipment including liquid level measurement, pressure gauges, and more.  Setpoint Integrated Solutions, headquartered in Baton Rouge, La., is a subsidiary of Pon Holdings B.V. of the Netherlands. Pon is an international trading and service organization with a workforce of 14,000 people spread over 450 locations in 32 countries.


For more information, please visit and


PDF Found Here

Setpoint Integrated Solutions Continues to Expand Territory Agreement with Ashcroft Inc.

Setpoint Integrated Solutions Continues to Expand Territory Agreement with Ashcroft Inc.

Media Contact:
Fatima Mehr, Director of Marketing

Baton Rouge, LA (July 31, 2020) – Setpoint Integrated Solutions (Setpoint I.S.) and Ashcroft Inc. will continue to build on their established partnership by expanding the existing Authorized Stocking Distributor agreement to include three new Texas locations for the sale of Ashcroft Inc.’s line of Pressure and Temperature Instruments.

“Ashcroft Inc. continues to be a valuable partner as we expand our valuable partner as we expand our distribution and seal assembly capabilities,” said Jeff Kelley, Vice President of Sales at Setpoint I.S. “This expansion allows Setpoint I.S. to further our vision of growth in the Texas market as well as build on our product portfolio, adding to the plant level service offerings across the Gulf Coast.”

Setpoint I.S.’ existing territory in the region includes the Texas “Golden Triangle” and East Texas. The expansion includes three new Setpoint I.S. Texas locations: La Porte, Richwood and Corpus Christi. These distributing facilities service the Houston, San Antonio, Austin and Corpus Christi areas for the sale of the Ashcroft Inc. Pressure and Temperature Instruments.

Setpoint I.S. and Ashcroft Inc.’s partnership dates back over 60 years, and Setpoint I.S. continues to be the legacy representative in the East Texas, Louisiana, Mississippi, Alabama and Florida panhandle territories. The expanded territory will capitalize on the successful track record of serving end user needs within the refining, petrochemical and power industries.

Products manufactured by Ashcroft Inc. have become the benchmark in pressure and temperature measurement and include gauges, thermometers, switches, transducers, transmitters, instrument isolators and diaphragm seals as well as control and calibration equipment.

For additional details, contact Stuart Prestridge, Corporate Director of Sales at or 225.921.9846.

About Setpoint Integrated Solutions

Setpoint Integrated Solutions is the leader in the process control industry with 11 facilities across the Gulf Coast. Supporting the Power, Refining, and Chemical Industries with best in class valve repair services, delivering process solutions for control, relief, and automated valve requirements, along with industrial equipment including liquid level measurement, pressure gauges, and more.  Setpoint Integrated Solutions, headquartered in Baton Rouge, La., is a subsidiary of Pon Holdings B.V. of the Netherlands. Pon is an international trading and service organization with a workforce of 14,000 people spread over 450 locations in 32 countries. 


For more information, please visit and


About Ashcroft
Ashcroft was founded over 165 years ago with a mission to protect our customers with a brand recognized for reliability and innovation in the fields of pressure and temperature measurement. Ashcroft maintains operations in the United States, Mexico, Brazil, Germany, China and Singapore along with over 235 channel partners in 55 countries supporting our customers around the world. Ashcroft is headquartered in Stratford, CT, USA and is a subsidiary of Nagano Keiki Co., Ltd. based in Tokyo, Japan. 


PDF Found Here

Clark Reliance Territory Expansion

Setpoint Integrated Solutions Expands Territory Agreement with Clark-Reliance



Setpoint Integrated Solutions expands territory agreement with Clark-Reliance.


Baton Rouge, LA (Dec. 4, 2018) – Setpoint Integrated Solutions (Setpoint I.S.) is pleased to announce that effective midnight Dec. 1, 2018 Setpoint I.S. will expand the exclusive Representative contract into Texas for following brands:

  • Jacoby-Tarbox® sight flow indicators, security sight windows, lighting products, eductors (jet pumps) and tank liquid agitators.
  • Jerguson® Gage & Valve reflex & transparent glass level gages, valves, and illuminators.
  • Jerguson® Magnicator Products magnetic level gages, switches, and transmitters.
  • Jerguson® (Magne-Sonics®) Level Switches external caged and top mount float & displacer switches
  • Reliance® boiler water level gages including: reflex, transparent mica protected, bicolor glass and conductivity probe remote type, valves and illuminators.


Setpoint I.S. and the Clark-Reliance Corporation’s partnership dates back to 2000, and Setpoint I.S. continues to be the legacy representative in North TX, Louisiana, Arkansas, and Southwest Mississippi Territories. The expanded territory will capitalize on the successful track record of serving end user needs within the refining, petrochemical, and power industries.


“Our goal from day one has been to align with “Best in Class” manufacturers who engineer products focused on improving the safety, reliability, and run time efficiency of our end users. Clark-Reliance has been a great partner for many years, and the expansion further into Texas will enhance our continued growth within Setpoint’s Instrumentation & Distributed Product Portfolio. ” said Jeff Kelley, Vice President of Sales and Marketing for Setpoint Integrated Solutions.  “To support the local customers, we have invested in additional inventory and personnel to maximize our ability to provide a rapid response, quick shipments, and technical support throughout the process,” Kelley continued.


For additional details, contact Stuart Prestridge, Director of Business Development at or 225.921.9846.  RFQ’s can be directed to and will be handled promptly.   


About Clark Reliance Corporation

Founded in 1884, Clark-Reliance is dedicated to supplying the largest and broadest product line in the instrumentation industry for all types of measurement and control. Key acquisitions over the last few decades have solidified Clark-Reliance as a leader in the separation and filtration industries as well.


Clark-Reliance now includes a number of distinguished product lines: Reliance®, Jerguson®, Jacoby-Tarbox®, Anderson® Separator and National Filtration Systems®


About Setpoint Integrated Solutions

Setpoint Integrated Solutions is the leader in the process control industry with 12 facilities across the Gulf Coast. Supporting the Power, Refining, and Chemical Industries with best in class valve repair services, delivering process solutions for control, relief, and automated valve requirements, along with industrial equipment including liquid level measurement, pressure gauges, PLC’s and more. Setpoint Integrated Solutions, headquartered in Baton Rouge, La., is a subsidiary of Pon Holdings B.V. of the Netherlands. Pon is an international trading and service organization with a workforce of 14,000 people spread over 450 locations in 32 countries. For more information, please visit and .


PDF found here.

Replace Your Globe Valves with the Camflex GR from Masoneilan

Replace Your Globe Valves with the Camflex GR from Masoneilan

Fast Facts about the Masoneilan Camflex :

  • First introduced in 1968 the Masoneilan Camflex Rotary Globe control valve has over 1.2 Million units installed worldwide
  • Setpoint Integrated Solutions has over 40,000 Camflex Rotary Globe control valves installed across the Gulf Coast coverage area
  • Per API 553 recommended practices for Refinery valves, Camflex Rotary Globe valve is recommended in refinery distillation, FCCU, catalytic reformer, delayed coker, gas plant,, and sulfur recovery unit.
  • Camflex Rotary Globe has performed for decades in difficult applications  including brine water, dry chlorine, HCL,  Heater Drain, Saturated Steam, Ammonia, Vinyl Chloride, Vinyl Acetate, Titanium Tetrachloride, Sulfuric Acid, Sulfur, Steam Condensate, Rich Amine, Bottom Residuals, Phosphorus Trichloride, Phosphorous acid, Alumina silica acid, Nitric Acid, Dowtherm, Green and Black Liquor.
  • Camflex Rotary Globe combined with the SVI II AP SMART positioner exhibits high-resolution throttling control performance achieving .002 inch step change (2 thousands of an inch), 0% overshoot, 1.5 sec. settling time, step change time .01 sec., wait time 10 sec.
  • Higher fluid recovery factor offering more resistance to cavitation than a segmented ball control valve
  • Multiple inherent flow characteristics are available including linear, =% 30, =% 50 and customized characterized characterization when combined with SVI II AP SMARt positioner
  • Slurry service design available with o-ring sealed bearings, hardened flow gallery, protected outlet, and ceramic trim options
  • Camflex Rotary Globe offers two face to face take out lengths, ISA S75.04 Segmented Ball Valve, and ISA S75.03 Globe Valve


The Camflex Rotary Globe valve offers several advantages over reciprocating control valves
  • Standard low emission packing in compliance with ISO-15848 & ANSI/FCI 91-1
  • 50% fewer parts, 50% fewer potential leak paths, 50% lighter than a typical reciprocating globe control valve
  • Higher turndown, 100:1 turndown as compared to reciprocating globe valve with 50:1
  • Multiple CV’s available for optimum control range where only a seat ring change-ou is required
  • Unique seating design offers standard ANSI/FCI 70-2 leakage class IV & V with metal to metal sealing components
  • Standard extended bonnet allows the use of low friction TFE packing over the full operating range

Baker Hughes’ Masoneilan Camflex GR

Baker Hughes’ Masonielan Camflex valve technology has over 1.2 Million units installed worldwide in refineries, petrochemical, and chemical plants. The original Camflex design, since being introduced in 1968, has been proven to be reliable where many typical valves fail. And now, the new Camflex GR (Globe Replacement) model makes operation and maintenance even easier.

Available in six sizes, 1″/ 1.5″/ 2″/ 3″/ 4″ / 6″ in carbon or stainless steel constructions.  Models rated for three classes 150 / 300 / 600 applications

With 50% fewer parts, the Camflex GR has simpler operation, easier maintenance, and lower inventory costs for spares.   It also features 50% fewer potential leak paths for higher efficiency and lower emissions.  It is lightweight, easy to handle, and simple to commission.

The Camflex GR is designed for direct, 1-to-1 replacement of most reciprocating valves. Its compact envelop makes it easy to install in any application, regardless of which OEM made your old valve.

Camflex GR’s rotary design has several advantages over  the typical reciprocating globe valves that it replaces. At the heart of the Camflex is the double eccentric plug design.  Eccentric rotating, self-aligning plug results in reliable shutoff and fewer leaks.

The eccentric action ensures no friction or contact between the plug and seat during operation. The only time the plug contacts the seat ring is when the valve closes.  This ensures consistent and tight shut off. Additionally, the  Camflex GR has 2x the Cv of conventional globe valves which provides exceptional turn-down, or rangeablility,  to cover many process conditions.

The rotary shaft motion reduces packing friction and wear, providing tighter longterm sealing. No sliding stem results in less friction, simpler packing.  The standard EF Seal provides low emission tightness.  The integral body design eliminates the typical gasketed body, or bonnet joint, simplifying maintenance and removing a potential leak point. Fewer gasketed joins results in less chance for environmental issues.  Direct mounting of positioners provides more accurate positioning control by eliminating intermediate linkage between the valve shaft and avoiding lost motion that could otherwise be caused by wear over time.

Most importantly,  unlike traditional globe valves,  the Camflex trim is designed  so that only the seat ring changes for different Cv requirements. Combined with a simpler design with less packing and no gaskets, this means few parts to stock and manage., resulting in huge cost savings.

Camflex GR is available from Setpoint Integrated Solutions through the ValvFast program, meaning kits are in-stock and can be configured to meet your application needs in as little as 24-hours.

Setpoint Integrated Solutions speaks to Baton Rouge Metro Council in Support of Exxon’s ITEP Approval

Setpoint Integrated Solutions Speaks to Baton Rouge Metro Council in Support of Exxon's ITEP Approval

Statement from Jeff Kelley, Vice President at Setpoint Integrated Solutions, to the Baton Rouge Metropolitan Council in support of Exxon’s BRPO project receiving ITEP approval

Baton Rouge, LA (October 10, 2018) – As a Vice President at Setpoint Integrated Solutions, I’m here to speak in support of Exxon’s BRPO project receiving its ITEP approval.

Setpoint provides products and valve services to the petrochemical, refining, and power markets, and since its founding in 1959 has called Baton Rouge home. As a leading company in the valve services industry, with over $200 Million in annual revenue, we are committed to supporting industrial growth that programs like ITEP encourage.

While our business has grown to cover the entire Gulf Coast region, we maintain our headquarters in Baton Rouge along Highland Rd. Looking at the Highland Rd area alone, there are multiple other peer companies who operate in the same business sector, providing similar products and valve services as Setpoint; so, while I am here as an officer of Setpoint, I feel I am also speaking on behalf of the valve service and distribution industry as a whole for the metro region.

At the end of the day, like any other business that relies on industry, our ultimate role is to provide for our employees, giving them a safe, stable, and prosperous career path. Setpoint employs 715 permanent employees with over 145 located within the Baton Rouge Metro area. These employees represent a diverse range of backgrounds and professions: from welders and machinists to engineers and accountants.

It is clear that a company like Exxon will need to have an economic justification to support their capital investment regardless of the final location. Importantly, what city and state they choose to invest in whether it’s Corpus Christi, TX – Baytown, TX – Beaumont, TX, or ideally Baton Rouge, Louisiana.

We need Exxon and the other companies watching this process closely to choose not only Louisiana as the destination for their next project, but specifically to invest in Baton Rouge.Thank you for allowing me time to speak and I appreciate the consideration and support of Exxon’s ITEP application.

PDF found here.

CONTACT:Wyatt Link, Marketing Specialist

Setpoint Integrated Solutions Phone: (225)-612-1167

Properly Protect Against Overpressure

Properly Protect Against Overpressure

Properly Protect Against Overpressure

Understand the appropriate use of different pressure relief devices.

By Amin Almasi, rotating equipment consultant

Many processes require a device to control or limit the pressure that can build up due to an upset , instru­ment or equipment failure, or fire. Pressure relief valves (PRV) most commonly provide this protection against overpressure but backflow preventers (such as check valves and others) and rupture disks also play useful roles in many applications. In addition, special classes of relief valves, usually known as vacuum relief valves, safeguard against excessive vacuum. Such devices actuate when pressure (or vacuum) exceeds a specified design value.

A conventional PRV is a self-actuated spring-loaded valve that opens at a designated pressure to allow the pressurized fluid to exit. (Some small valves commonly handle thermal relief valve applications.) The basic ele­ments of a spring-loaded PRV include an inlet nozzle connected to the vessel or system to be protected, a movable disk that regulates flow through the nozzle, and a spring that controls the position of the disk.

Under normal system operating conditions, the pressure at the inlet is below the set pressure – so, the disk is seated on the nozzle, preventing flow through it.

However, when the set pressure is exceeded, the relief valve opens and becomes the “path of least resis­ tance” for flow. A portion of the fluid exits the PRV, usually going through a piping system known as a flare header or relief header to a central, elevated gas flare (or similar) for combustion. The loss of fluid lowers the pressure inside the machinery or system being pro­ tected. When the pressure declines enough, the PRV will close. How much the pressure must drop before the valve reseats is termed blow-down and often is stated as a percentage of set pressure. Roughly, this can range from 3% to 20%; some valves have adjustable blow-downs.


Figure 1. When open, this valve vents fluid to atmosphere.

In systems where the outlet is connected to piping, the PRV’s opening will prompt a pressure build  up in the downstream piping. Other PRVs connected to the outlet pipe system may open and the pressure in

the exhaust pipe system may increase . This may cause undesired operation. So, such systems frequently need an alternative solution. They often require “differen­tial” relief valves –  in these, the pressure works on an area much smaller than the opening area of the valve.

The pressure must decrease enormously before the valve closes; also the outlet pressure of the valve can easily keep the valve open.

In some cases, a bypass valve protects a pump or gas compressor and any associated equipment from excessive pressure . It acts as a relief valve by returning

all or part of the fluid discharged by the pump or com­ pressor back to either a storage reservoir or the inlet of the machine. The bypass valve and bypass path can be internal (an integral  part of the  pump or compressor) or external (installed as a component in the fluid path) .


The operation of this device is based on a force bal­ance. The spring load is preset to equal the force exerted on the closed disk by the inlet fluid when the system pressure is at the PRV’s set pressure. When the inlet pressure is below the set pressure, as it should be for normal operations, the disk remains seated on the nozzle in the closed position. As the system pressure approaches the set pressure of the valve, the seating force between the disk and the nozzle approaches zero.

When the inlet pressure exceeds set pressure, the pressure force on the disk overcomes the spring force and the valve opens. Then when the inlet pressure falls to the closing pressure, the valve recloses.

Historically, many liquid applications used PRVs (or pressure safety valves) designed for compressible (or vapor) service. Many of these valves when used in liquid service required high overpressure (say, 20%) to achieve full lift and stable operation because liq­ uids don’t provide the expansive forces that vapors do. Where liquid PRVs had to operate with a 10%

overpressure limit, a conservative factor (say, 0.6) usu­ ally was applied to the valve capacity during sizing.

Consequently, many installations were oversized and instability sometimes resulted.

Codes now incorporate rules that address perfor­ mance ofliquid service valves at 10% overpressure and that require a capacity certification. Vendors have

developed PRVs for liquid services that achieve full lift, stable operation and rated capacity at 10% over­ pressure in compliance with the requirements; some designs feature adjustable blow-down. Valves that can operate on liquid and gas are available. However, such valves may exhibit different operational characteristics depending upon whether the flow stream is liquid, gas or a combination of the two. Many PRVs designed for liquid service, for example, will have a much longer blow-down (typically 20%) on gas than on liquid ser­ vice. Additionally, some variation in set pressure may occur if the valve is set on liquid and required to oper­ ate on gas or vice versa.

Pressure existing at the outlet of a PRV  is defined as backpressure. This backpressure may cause varia­ tions in opening pressure, reduction in flow capacity, instability or a combination of all three. A balanced spring-loaded PRV minimizes the effects ofbackpres­ sure on the performance characteristics of the valve; it incorporates a bellows, a sealed piston or other means of balancing the valve disk. Consider a balanced PRV wherever the backpressure  created by flow through the downstream piping after the relief valve lifts is too high for a conventional PRV. Balanced PRVs also can

serve to isolate the guide, spring, bonnet and other top works parts within the valve from the relieving fluid. This may be important if corrosive damage to these parts from the fluids (such as dirty ones from down­ stream) is a concern.

Two-phase systems in which the fluid being relieved may be liquid or gas call for spring-loaded PRVs designed for liquid (or liquid-and-gas) service and bal­ anced to minimize the effects ofbackpressure. Many manufacturers recommend use of valves designed for liquid or liquid-and-gas service if the mass percent­ age of vapor in the two-phase  mixture at the valve inlet is 50% or less. If you’re not certain of the ratio of liquid to gas in the flow stream, selecting a valve spe­ cifically designed for liquid or liquid-and-gas service is prudent.

Conventional PRVs perform unsatisfactorily when excessive backpressure develops during a relief inci­ dent, due to the flow through the valve and outlet piping. The built-up backpressure opposes the lifting force that’s holding the valve open . Excessive built-up backpressure can make the valve operate in an unsta­ ble manner. This instability may occur as chatter or flutter. Chatter refers to an abnormally rapid recipro­ cating motion of the valve disk where it contacts the seat during cycling. This type of operation may cause damage to the valve and interconnecting piping. Flut­ ter is similar to chatter except the disk doesn’t contact the seat during cycling.

As a rough guide, in a conventional PRV applica­ tion, built-up backpressure shouldn’t  exceed 10% of the set pressure at 10% allowable overpressure. You may use a higher maximum built-up backpressure for allowable overpressures greater than 10% –  provided the built-up backpressure doesn’t surpass the allowable overpressure. When the superimposed backpressure is constant, you can reduce the spring load to compensate for the superimposed backpressure. When the back­ pressure is expected to exceed these specified limits, specify a balanced or pilot-operated PRV.



This device consists of the main relief valve, which normally encloses a floating unbalanced piston assembly, and an external pilot (usually a conventional PRV).

The piston is designed to have a larger area on the top than on the bottom. Up to the set pressure, the top and bottom areas are exposed to the same inlet operating pressure. Because of the larger area on the

top of the piston, the net force holds the piston tightly against the main valve nozzle. As the operating pres­ sure increases, the net seating force rises and tends

to make the valve tighter . This feature allows most pilot-operated valves to be used where the maximum expected operating pressure is higher than the percent­ age acceptable for conventional relief valves. At the

set pressure, the pilot vents the pressure from  the  top of the piston; the resulting net force is now upward, causing the piston to lift and thus permitting fluid flow through the main valve. After the overpressure inci­ dent, the pilot will close the vent from the top of the piston, thereby reestablishing pressure; the net force will cause the piston to reseat.

The main valve of the pilot-operated PRV can use a diaphragm system in place of a piston to provide the unbalanced moving component. A disk, which

normally closes the main valve inlet, is integral with a flexible diaphragm. The external pilot serves the same function to sense fluid pressure, vent the top of the diaphragm at set pressure, and reload the diaphragm once the fluid pressure is reduced. As with the piston valve, the seating force increases proportionally with the operating pressure because of the differential exposed area of the diaphragm. Built-up backpressure doesn’t affect the lift of the main valve piston or dia­ phragm. This allows for higher pressures in the relief discharge manifolds than prudent with conventional and balanced spring-loaded PRVs.

The modulating pilot can handle gas, liquid or two­ phase flow applications. In contrast to a pop-action PRV, a modulating pilot-operated valve limits the amount of relieving fluid to just the amount necessary to prevent the pressure from exceeding the allowable level. Because a modulating pilot only releases the required relieving rate, you can calculate the built-up backpressure based on that rate instead of the rated

relieving capacity of the valve. The modulating pilot valve also can reduce interaction with other pressure control equipment in the system during an upset con­ dition, decrease unwanted atmospheric emissions, and lower the noise level associated with discharge to the flare piping or atmosphere .



You need a backflow preventer when there’s a possi­ bility of developing a pressure on the discharge side of the valve that exceeds its inlet pressure. The higher discharge pressure can create sufficient upward force on the diaphragm, piston or other element to open the valve and cause flow reversal. Reverse flow can occur with any standard type or design of pilot-operated PRV when sufficient reverse differential pressure exists.

A backflow preventer permits the introduction of outlet pressure into the dome of the main valve, thereby holding the piston firmly on the nozzle and overcoming the effect of a reverse differential pressure. The backflow preventer allows the discharge pressure to provide a net downward force on the diaphragm or piston to keep the valve closed. Proper operation of the backflow preventer is critical to further ensuring no flow reversal occurs in the valve. The material and seals in the backflow preventer should match those of the pilot-operated PRV.


These are non-reclosing devices for protecting against excessive pressure (or sometimes vacuum). A single or multiple rupture disks may be used in an instal­ lation. They also can serve as redundant pressure relief devices.

With no moving parts, rupture disks are simple and reliable –     and faster acting than other pressure relief devices. Rupture disks react quickly enough to relieve some types of pressure spikes. Because of their light weight, rupture disks can be made from high-alloy and other corrosion-resistant materials that aren ‘t practical for relief valves.

A rupture disk is also a temperature-sensitive device. Burst pressures can vary significantly with its temperature, which may differ from the normal fluid operating temperature . As the temperature at the disk increases, the burst pressure usually decreases. Because the effect of temperature depends upon the rupture disk design and material, consult the manu­facturer for specific applications. Specify the pressure and temperature at which the disk is expected to burst.


Carefully evaluate the contingencies that can cause overpressure in terms of the pressures generated and the rates at which fluids must be relieved. You need the package’s process and instrumentation drawings, equipment specification sheets, and design basis for the facility to calculate the individual relieving rates for each pressure relief device. An important parameter is the set pressure of a PRV installed in the machinery, package or facility. As a rough guide, this set pressure could be 110% of the maximum allowable working pressure (MAWP) in the package or system protected by a single pressure relief device sized for operating (non-fire) contingencies .

A multiple-device installation requires the combined capacity of two or more pressure relief devices to alle­viate a given overpressure contingency. In this way, you might increase the set pressure, for instance , to 118% of the MAWP in a package protected by multi­ple pressure relief devices sized for operating (non-fire) contingencies . For fire cases, the relief pressure (set pressure) usually is higher – e.g., it could be around 120% or 125% of the MAWP in a package protected by devices sized for fire contingencies.


An unbalance or disruption of the normal flows of fluid and energy in a machinery system or package can prompt the energy or fluid, or both, to build up in some part of the package (such as its discharge). Analysis of the causes and magnitudes of this over­ pressure, therefore, is a special and complex study of energy and fluid balances in different machinery oper­ating scenarios.

Double-jeopardy scenarios usually aren’t credi­ble ones for sizing a PRV. Such scenarios generally involve two independent failures or malfunctions at  the same time – e.g., simultaneous failures of two completely independent machines or controls, or oper­ator error leading to a blocked outlet coincident with an overall plant power failure. On  the  other hand, treat instrument-air failure during fire exposure as a single jeopardy if the fire exposure causes local air­ line failures.

Excessive speed and other machinery malfunctions can result in overpressure. Sometimes, the  inad­vertent opening of a valve from a source of higher pressure, such as a high-pressure  process fluid, can lead to overpressure. For instance, in many packages the re’s always a possibility of the suction system becoming pressurized by the discharge (high-pres­sure) fluid; in many cases, some portion of the suction system actually is designed based on discharge pres­sure or other means of protection (such as a PRV is considered.

A single check valve isn’t always an effective means for preventing overpressure by reverse flow from a high-pressure source such as a high-pressure discharge. For example, if a fluid is pumped or compressed into a system that contains fluid at significantly higher pres­ sure th an the design rating of the equipment upstream (suction) of the pump or compressor, loss of pumped flow with leakage or latent failure of a check valve in the discharge line results in a reversal of the fluid’s flow. When high-pressure fluid enters the low-pres­ sure system, overpressure can result . In most cases, you should focus on prevention of reverse flow. It’s important to note that , in addition to overpressure of the upstream system (or suction system), reverse flow through machinery might destroy mechanical equip­ ment, causing loss of containment. In many cases, this hazard is of concern , so provide additional means of backflow prevention.

Even proper inspection and maintenance might not completely eliminate check-valve seat leakage and leakage will occur. Consequently, even without total failure of the check valve, the low-pressure system upstream of a check valve still could be over-pressurized. A detailed analysis and study on a case-by-case basis then can show whether automatic isolation, a pressure-relief device sized for leakage, or an alternative means of protection is needed. You must define the appropriate leakage rate for each

specific machinery system. Experience has shown that when inspected and maintained to ensure reliability and capability to limit reverse flow, two back-flow­ prevention devices in series suffice to eliminate significant reverse flow.

In addition, carefully evaluate the possibility of overpressure developing from the loss of any utility service (such as cooling water, electricity, etc.), whether plant-wide or local.

AMIN ALMASI is a rotating equipment consultant based in Sydney, Australia. This post originally appeared in Chemical Processing Special Report: Review Your Rupture Disc Regimen found here.