Wednesday, November 14, 2018

Replace Old Boiler Damper Drives with Better Performing, Drop-in Replacements

Type K Damper Drive
Industrial dampers and louvers are used to precisely control combustion air and flue gases in power plants, refineries, powerhouse boilers, furnaces and process heaters. A damper drive is a specialized pneumatic or electric actuator that positions air and flue gas dampers on combustion based systems in industrial environments.

Damper drives can provide linear or rotary motion to meet certain application requirements. The damper positioning is a process control function that is used to increase efficiency, reduce maintenance, control harmful emissions, and lower fuel consumption.

Damper drives have been installed in commercial and industrial application for many decades, and the replacement of older and obsolete models is an ongoing concern for operators. Retro-fitting an existing damper drive application can be mechanically challenging and labor-intensive. "Drop-in" refers to fitting in the existing drive's footprint, bolting pattern, and overall size envelope, so any replacement claiming "drop-in" compatibility is favorable in terms of time and materials.

Rotork, a globally recognized manufacturer of valve and damper actuators, has developed a product series within their damper drive line that specifically addresses the drop-in replacement of legacy damper drives.

Rotork's PM and DM Series drives, a portion of the company's Type K Damper Drive line, provide rotary operation in the 30 to 100 degree range and are available as pedestal mount or direct mount versions. As a subset of this broad offering, the company has crafted the FasTrak Series, which are preconfigured as ready-made units to replace common, older legacy damper drives. Twelve models cover the most commonly occurring pneumatic or electric damper drive replacements. The manufacturer states that the FasTrak drives will:
  • Bolt to the floor where the old drive was mounted
  • The existing link rod and clevis will attach to the FasTraK drive lever
  • Simply verify envelope dimensions to assure that there are no external obstructions
A product catalog describing the full line of Type K drive can be found here. For more information, contact CTi Controltech at 925-208-425 or visit their website at https://cti-ct.com.

Tuesday, October 30, 2018

The Flowserve Logix 3800 Digital Valve Positioner


The Logix 3800 positioner features powerful diagnostics that identify field problems and expedite corrective actions to ensure reduced return-to-operation times.

Compatible with linear and rotary valves and actuators, the robust design of the Logix 3800 delivers high reliability in tough environments, reduces inventory costs and contributes to a lower total cost of ownership, and installs with an innovative, one-button quick calibration feature.

Partial List of Features:
  • Rugged, certified SIL 3 capable modular design delivers maximum reliability in the toughest environments. 
  • Installation and operation ease from innovative quick calibration feature to simplify commissioning. 
  • Broad application versatility with industry-leading communication technologies, including analog, HART, Foundation Fieldbus, 4-20 or discrete I/O signals.
  • Intrinsically safe, non-incendive and explosion-proof design from -52°C to 185°C (-62°F to 365°F) ensures safe, reliable operation in hazardous conditions for increased plant and personnel safety.
  • Compatible with a variety of valve and actuation configurations including: rotary or linear valves; double- or single-acting; air- to-open or air-to-close.
https://cti-ct.com
925-208-4250

Monday, October 22, 2018

Control Valves by CTi Controltech


CTi Controltech handles a complete portfolio of control valves. From linear control valves to rotary control valves, CTi can handle the most severe services, including cryogenic, superheated steam, volatile, erosive, and corrosive fluids, high pressure drops, vibration, cavitation, flashing, and high noise levels. CTi's applications engineers can select and size the best choice for your application, and counsel you on the best practices for safety, accuracy, and long operating life.

925-208-4250

Sunday, September 30, 2018

Steam Metering and Steam Flow Measurement

Steam Flow Measurement
For steam, energy is primarily contained in the latent heat and, to a lesser extent, the sensible heat of the fluid. The latent heat energy is released as the steam condenses to water. Additional sensible heat energy may be released if the condensate is further lowered in temperature. In steam metering, the energy content of the steam is a function of the steam mass, temperature and pressure. Even after the steam releases its latent energy, the hot condensate still retains considerable heat energy, which may or may not be recovered (and used) in a constructive manner. The energy manager should become familiar with the entire steam cycle, including both the steam supply and the condensate return.

When compared to other liquid flow metering, the metering of steam flow presents one of the most challenging metering scenarios. Most steam meters measure a velocity or volumetric flow of the steam and, unless this is done carefully, the physical properties of steam will impair the ability to measure and define a mass flow rate accurately.

Steam is a compressible fluid; therefore, a reduction in pressure results in a reduction in density. Temperature and pressure in steam lines are dynamic. Changes in the system’s dynamics, control system operation and instrument calibration can result in considerable differences between actual pressure/temperature and a meter’s design parameters. Accurate steam flow measurement generally requires the measurement of the fluid’s temperature, pressure, and flow. This information is transmitted to an electronic device or flow computer (either internal or external to the flow meter electronics) and the flow rate is corrected (or compensated) based on actual fluid conditions.

The temperatures associated with steam flow measurement are often quite high. These temperatures can affect the accuracy and longevity of metering electronics. Some metering technologies use close-tolerance moving parts that can be affected by moisture or impurities in the steam. Improperly designed or installed components can result in steam system leakage and impact plant safety. The erosive nature of poor-quality steam can damage steam flow sensing elements and lead to inaccuracies and/or device failure.

The challenges of metering steam can be simplified measuring the condensed steam, or condensate. The metering of condensate (i.e., high-temperature hot water) is an accepted practice, often less expensive and more reliable than steam metering. Depending on the application, inherent inaccuracies in condensate metering stem from unaccounted for system steam losses. These losses are often difficult to find and quantify and thus affect condensate measurement accuracy.

Volumetric metering approaches used in steam metering can be broken down into two operating designs: (1) differential pressure and (2) velocity metering technologies. For steam three differential pressure meters are highlighted: orifice flow meter, annubar flow meter, and spring-loaded variable area flow meter. All differential pressure meters rely on the velocity-pressure relationship of flowing fluids for operation.

Differential Pressure – Orifice Flow Meter. Historically, the orifice flow meter is one of the most commonly used meters to measure steam flow. The orifice flow meter for steam functions identically to that for natural gas flow (see previous section). For steam metering, orifice flow meters are commonly used to monitor boiler steam production, amounts of steam delivered to a process or tenant, or in mass balance activities for efficiency calculation or trending.

Differential Pressure – Annubar Flow Meter. The annubar flow meter functions the same way for steam flow as it does for natural gas flow.

Differential Pressure – Spring-Loaded Variable Area Flow Meter. The spring-loaded variable area flow meter is a variation of the rotameter. There are alternative configurations but in general, the flow acts against a spring-mounted float or plug. The float can be shaped to give a linear relationship between differential pressure and flow rate. Another variation of the spring-loaded variable area flow meter is the direct in-line variable area flow meter, which uses a strain gage sensor on the spring rather than using a differential pressure sensor.

The two main type of velocity meters for steam flow, turbine and vortex shedding, both sense some flow characteristic directly proportional to the fluid’s velocity.

Velocity – Turbine Flow Meter. The turbine flow meter functions the same way for steam flow as it does for natural gas flow.
Velocity – Vortex-Shedding Flow Meter. The vortex-shedding flow meter functions the same way for steam flow as it does for natural gas flow.

Friday, September 21, 2018

Industrial In-line, Spring-loaded Check Valves

Check-All Check Valve
Check-All Check Valve
Check-All Valve manufactures in-line spring-loaded poppet-type check valves, vacuum breakers, and low pressure relief devices. All valves are available with metal to metal or soft seats. Sizes range from 1/8” NPT to 20 inch flanged connections. Pressure ratings are available from full vacuum to 10,000 psi. Special materials available are Titanium, Alloy C-276, alloy 20 and many others. Fluoropolymer (FEP) encapsulated springs are available for special corrosion applications.

Certifications & Compliances
  • ISO 9001
  • 3-A Sanitary Standards
  • B16.34 Certification
  • Canadian Registration Number
  • CE (PED 2014/68/EU) Conformance
  • NACE Standards
For more information, download the Check-All Valve Product Catalog from this link, or view the embedded document below.

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

Friday, August 31, 2018

Rupture Discs for Sanitary and Hygienic Applications in Pharmaceutical, Biotech, Food, and Beverage Facilities

SANITRX HPXContinental Disc Corporation's SANITRX HPX & SANITRX HPX II Rupture Discs are semicircular scored reverse acting rupture discs designed specifically for the pharmaceutical, biotech, food and beverage industries. These rupture discs are available to fit between industry standard sanitary ferrules, NA-CONNECT® flanges or SANITRX fittings.

The SANITRX HPX & SANITRX HPX II Rupture Discs can be used in a wide range of sanitary and hygienic applications throughout pharmaceutical, biotech, food, and beverage facilities. The following list is only a small sample of the many ways in which this outstanding rupture disc can be used:
  • Autoclaves
  • Bioreactors
  • Clean Steam Piping 
  • Process Vessels 
  • Heat Exchangers 
  • Filters
  • Storage & Transport Vessels
  • Mixing, Drying, Granulating Equipment 
  • Wfi Vessels & Piping
  • Lyophilizers (Freeze Drying)
  • Cip & Sip Skids and Piping
  • Fermenters
To learn more about sanitary and hygienic rupture discs, review the embedded document below or download a PDF of the Continental Disc Corporation Sanitrx HPX & Sanitrx HPX II Rupture Disc brochure here.

Wednesday, August 15, 2018

Detonation Flame Arresters

Detonation Flame Arrester
Detonation Flame Arrester (Groth Corporation)
Detonation flame arresters are designed to prevent flame propagation in gas piping systems which contain flammable gas/vapor mixtures. It operates by removing heat from the flame as it attempts to travel through narrow passages with heat-conductive walls. The arrester will stop a high velocity flame by absorbing heat away from the flame head, which lowers the burning gas/air mixture below its auto-ignition temperature, and creating an atmosphere where the flame cannot be sustained. The arrester must prevent flame passage under certain specified conditions while permitting free flow of gas/vapor through the system. The channels or passages in the flame arrester are designed to very efficiently conduct heat outward, but still allow the gasses to flow. Thus it protects vulnerable equipment or components of the system from damage due to explosive pressures caused by gas/vapor ignition in another part of the system. The detonation flame arrester must be used under only those operating conditions for which it was designed and tested.

The flame arresters consist of two main components, the arrester bases and the flame element housing assembly. The bases serve as the connecting interface to the piping system. The housing retains and supports the flame element. Both components are essential in stopping the passage of the flame.

The flame element is comprised of small parallel passageways aligned so that an approaching flame front is slowed down and then quenched before it can propagate to the protected side of the device.

The bases must also withstand the detonation pressures while conveying the burning vapors and flame front to the element. Depending on the design of the system in which it is used, the arrester bases can include optional ports for thermocouples or pressure monitoring devices. These devices can activate warning or shutdown systems if abnormal conditions are detected. Both bases may be equipped with large diameter inspection/clean-out ports for in-line maintenance of the element, or element removal may be required for inspection/maintenance.

Flame arresters are used in many industries including chemical, refining, petrochemical, pulp and paper, oil exploration and production, pharmaceutical, sewage treatment, landfills, power generation, and bulk liquids transportation.

Please always consult with a properly qualified applications specialist prior to specifying, purchasing, or applying flame arresting devices.

Monday, July 23, 2018

Basics of Magnetic Flowmeters

Magnetic flow meter
Magnetic flowmeter
(Azbil)
Crucial aspects of process control include the ability to accurately determine qualities and quantities of materials. In terms of appraising and working with fluids (such as liquids, steam, and gases) the flowmeter is a staple tool, with the simple goal of expressing the delivery of a subject fluid in a quantified manner. Measurement of media flow velocity can be used, along with other conditions, to determine volumetric or mass flow. The magnetic flowmeter, also called a magmeter, is one of several technologies used to measure fluid flow.

In general, magnetic flowmeters are sturdy, reliable devices able to withstand hazardous environments while returning precise measurements to operators of a wide variety of processes. The magnetic flowmeter has no moving parts. The operational principle of the device is powered by Faraday's Law, a fundamental scientific understanding which states that a voltage will be induced across any conductor moving at a right angle through a magnetic field, with the voltage being proportional to the velocity of the conductor. The principle allows for an inherently hard-to-measure quality of a substance to be expressed via the magmeter. In a magmeter application, the meter produces the magnetic field referred to in Faraday's Law. The conductor is the fluid. The actual measurement of a magnetic flowmeter is the induced voltage corresponding to fluid velocity. This can be used to determine volumetric flow and mass flow when combined with other measurements.

The magnetic flowmeter technology is not impacted by temperature, pressure, or density of the subject fluid. It is however, necessary to fill the entire cross section of the pipe in order to derive useful volumetric flow measurements. Faraday's Law relies on conductivity, so the fluid being measured has to be electrically conductive. Many hydrocarbons are not sufficiently conductive for a flow measurement using this method, nor are gases.

Magmeters apply Faraday's law by using two charged magnetic coils; fluid passes through the magnetic field produced by the coils. A precise measurement of the voltage generated in the fluid will be proportional to fluid velocity. The relationship between voltage and flow is theoretically a linear expression, yet some outside factors may present barriers and complications in the interaction of the instrument with the subject fluid. These complications include a higher amount of voltage in the liquid being processed, and coupling issues between the signal circuit, power source, and/or connective leads of both an inductive and capacitive nature.

In addition to salient factors such as price, accuracy, ease of use, and the size-scale of the flowmeter in relation to the fluid system, there are multiple reasons why magmeters are the unit of choice for certain applications. They are resistant to corrosion, and can provide accurate measurement of dirty fluids ' making them suitable for wastewater measurement. As mentioned, there are no moving parts in a magmeter, keeping maintenance to a minimum. Power requirements are also low. Instruments are available in a wide range of configurations, sizes, and construction materials to accommodate various process installation requirements.

As with all process measurement instruments, proper selection, configuration, and installation are the real keys to a successful project. Share your flow measurement challenges of all types with a process measurement specialist, combining your process knowledge with their product application expertise to develop an effective solution.

Tuesday, July 17, 2018

Industrial Ball Valve Basics

Specialized ball valve
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 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 valve
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.

Tuesday, July 3, 2018

Saturday, June 30, 2018

MOGAS iRSVP Power Industry Valve Designation and Markings

MOGAS iRSVP Series
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

Sunday, June 24, 2018

Convenient Rupture Disc Selection Form from Continental Disc Corporation

CDC rupture disc
CDC rupture disc.
Continental Disc Corporation is a leading manufacturer of rupture disc (bursting disc) devices for a variety of process industries, including chemical, petrochemical, petroleum refining, pharmaceutical, food and beverage, aerospace, industrial gases, transportation, and other markets worldwide.

They have a very convenient online form to assist in replacement of an existing rupture disc, or to specify a new installation. The form can be found by following this link. The form gives you the option to print it from its online page, or to email the form to Continental Disc sales department for a quotation.

In 2017, CTi Controltech was appointed the exclusive Continental Disc and Groth Equipment representative in Northern California and Nevada.

Friday, June 15, 2018

Pneumatic Damper Drives Superior to Electric Drives on Boiler Dampers

Pneumatic Damper drives
Pneumatic Damper Drives (Rotork)
In flue gas and combustion air applications, rapid response is critical for optimal efficiency, safety, and equipment longevity. Pneumatic vane damper drives don't have gears or motor windings that slow down response or introduce slop. In power plants boiler applications, Rotork Type K damper drives continue to provide a better solution for critical damper applications over electric drives.

Electric Drive
Old Electric Drive
Balanced-draft power generation boilers can experience very serious equipment failures if low pressure conditions exist inside the combustion chamber. Transients in boiler pressure can cause combustion complications leading to irregular heating of steam tubes, and in extreme situations, negative boiler pressure can collapse boiler walls and buckstays. There is a possibility for catastrophic failures (ruined boiler tubes, destroyed  refractory, boiler structural damage) leading to long shutdowns, lost production, and expensive re-construction. Pneumatic damper drives are excellent alternatives to electric drives in these applications because of speed, accuracy, and reliability.

Understanding the catastrophic possibilites, it is extremely important to provide consistent internal operating pressure environment for efficient and manageable combustion. ID (induced draft) fans on combustion boilers play a critical role in maintaining reliable boiler pressure. In turn, the ID fan inlet damper control system that regulates fan induced airflow and pressure need to be accurate, responsive, and reliable to assist in keeping boiler combustion chamber pressure fluctuations in check. Pneumatic vane drives react to signal changes and produce movement instantaneously and repeatably.
Pneumatic drive
New Pneumatic Drive

Rotork Type K PM Series Pedestal-Mount Damper Drives have proven themselves time and time again as the best choice for these applications. Pneumatic vane drives deliver high torque at tested speeds of less than 3 seconds for a full 90-degree stroke. They offer drop-in-place retrofit to the existing damper drive footprint, plus smart positioner technology. The Type K Drives perform quickly and smoothly at full boiler pressure and damper load, and as required, fail to the fully closed position.

The data collected after years of maintenance-free operation, in thousands of successful installations world-wide, is compelling. Pneumatic drives are superior to electric drives on boiler dampers.

Always discuss your damper drive application with an experienced applications engineer for best selection, optimal performance, and maximum safety.

Thursday, May 31, 2018

Increased cycle count improves operational efficiency in slurry ore mining operations

slurry pipeline
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
MOGAS valve
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.

Wednesday, May 23, 2018

Welcome to CTi Controltech

Since 1976 CTi Controltech has represented the leading process control and combustion manufacturers.  These products, together with our engineering capabilities, give CTi customers high quality solutions to the most difficult industrial applications.

CTi is focused on the top quality manufacturers in process control, valves, instrumentation, and combustion. Over the past three decades CTi has continually added and upgraded the quality of companies it represents.

Our staff of engineers and technicians is well versed with all our products and are ready to help you with your most demanding applications.

Wednesday, May 9, 2018

Rupture Disc Assemblies Designed to Protect Tanks Against Implosion or Overpressure Conditions

CAL-VAC POS-A-SET
CAL-VAC and POS-A-SET
Continental Disc Corporation's CAL-VAC® and POS-A-SET® Rupture Disc Assemblies are highly accurate, double acting pressure relief devices designed to protect processing and storage tanks against implosion or overpressure conditions that can occur in:
  • Positive Pressure - overfill, external fire, steam regulator failure 
  • Vacuum Relief  - liquid pump out, insufficient flow through sanitary vent filer, flash vacuum due to CIP cool rinse, primary vent malfunctions, blanket gas or air regulator failure
Both designs relieve pressure settings starting as low as 1 InWC (inches water column) differential. The difference in the CAL-VAC Rupture Disc and POS-A-SET Rupture Disc is the orientation of the components to meet the relieving requirements. The CAL-VAC Rupture Disc relieves ultra low pressure in the vacuum (negative) pressure direction, while the POS-A-SET Rupture Disc relieves ultra low pressure in the positive pressure direction.

Wednesday, March 28, 2018

Fluid Processing - Plug Valves

plug valve cutaway view
Plug valve cutaway view
Image courtesy Flowserve - Durco
Fluid process control operations commonly employ pumps, piping, tanks and valves as the means of transporting, containing and controlling the fluid movement through a system.

Valves, of which there are many types, provide control over the flow rate, direction and routing of fluids in a processing operation. Flow can be started, stopped or modulated between zero and full rate using a properly sized and configured valve. Some valves enable media flow to be diverted to a selection of outlets, in lieu of a single inlet and outlet pair. Specialized valves regulate inlet or outlet pressure, or prevent fluid flow from going in an undesirable direction. All of these capabilities are packaged into differing valve product offerings that present a very large selection array to a process designer or engineer.

Industrial flow control valve types are generally classified according to the structure or arrangement contained within the valve body that provides obstruction to fluid flow. Some of the common types are ball, butterfly, gate, globe, and plug. Surely, there are more valve types, and this article is not intended to list them all. Some of our previous blogs have discussed selection considerations for gate, ball and butterfly valves. This article will focus on one of the oldest valve types, the plug valve.

Plug valves, like ball and butterfly valves, span from fully open to fully closed positions with a shaft rotation of 90 degrees. The “plug” in a plug valve is installed in the flow path within the valve body and rotated by means of a stem or shaft extending to the exterior of the body. Plugs are often tapered toward the bottom and are fitted to a seating surface in the valve body cavity that prevents fluid from bypassing the plug. An opening through the plug, the port, can be shaped to provide particular flow characteristics. There are numerous variants of the basic plug valve which may make it suitable for particular applications. One common variant is the lined or sleeved plug valve, with an insert or interior lining of material that creates an isolating barrier between the valve body and the media. This allows use of less expensive materials for the body construction that may be otherwise subject to corrosion by exposure to aggressive media.

Plug valves can be selected for a number of attributes.
  • 90 degree rotation from open to closed provides fast operation.
  • With proper configuration, can be well suited for frequent operation.
  • Availability of corrosion resistant liner may provide comparative cost savings because valve body can be constructed of less expensive material.
  • Design is simple and employs a low parts count.
  • Valve can be serviced in place.
  • Generally, low resistance to flow when fully open.
  • Reliable leak-tight service due to tapered plug wedging action, replaceable sleeve, and injection of lubricant in some variants.
Potential issues of concern for plug valve application include a short list of items.
  • Higher friction in the plug closure mechanism may require comparatively higher operating torque than other valve types.
  • Without a specially designed plug, generally not well suited for throttling applications.
  • Rapid shutoff delivered by plug design may not be suitable for some applications where hammering may occur.
Share your fluid control application challenges with a valve and automation specialist. Leverage your own knowledge and experience with their product application expertise to develop an effective solution.

Wednesday, March 21, 2018

Master-Martyr Valve Arrangements

electric industrial valve actuator with manual wheel
Electric actuator for industrial valves.
Image courtesy Rotork
Some industrial fluid flow applications are best served with what is known as a master-martyr valve set. Let's look at this arrangement and how it is used.

Valves are used to regulate flow. They are also applied to isolate portions of a fluid system by providing positive leak free shutoff. A master-martyr valve set utilizes two valves, with the performance of each targeted at differing performance goals. By coordinating the operation of the two valves, operational benefits accrue.

The master valve serves as the isolating valve. It will be located upstream of the martyr valve. The master valve provides fully open or fully closed operation and is commonly selected to accommodate the most severe operating condition anticipated in the system. Usually, this valve is normally open and is designed to contribute little to no pressure drop to the fluid flow. A good example is a full port metal seated ball valve. It offers very low pressure drop, substantial resistance to system pressure or heat, and can be driven from fully open to closed positions quickly.

The martyr valve provides flow regulation or throttling and is not intended to be the positive means of shutoff for the fluid flow. This valve will experience a range of pressure drop, possibly some flashing, or other conditions that, along with the frequent repositioning applied to the valve, will serve to produce wear and tear on the mechanism. Generally, the martyr valve is expected to wear out from normal operation and need servicing or replacement. The master valve, located upstream, serves as a point of isolation that allows the martyr valve to be easily serviced.

The overall goal is to operate the master valve as little as possible and expose it to the lowest possible pressure drop. Generally, this will call for the master valve to be opened first and closed last.

There are numerous potential applications for this valve arrangement. Smart actuators can function within the control system by delivering information about valve position and service level, as well as responding accurately to system commands. Share your fluid flow control challenges and applications with valve automation specialists. Leverage and effective solution by combining your own knowledge and experience with their product application expertise.

Tuesday, March 13, 2018

Patented Ballcheck Valve Eliminates Potential Commissioning Error



When using a ballcheck valve and commissioning a gauge assembly on a vessel containing liquid, a common mistake is to open the valve too quickly and engage the ball check. This will result in a false reading on the gauge. The 360 Series valve, from Jerguson, makes it impossible to get a false level reading during commissioning. The short video shows how the patented feature of the 360 simplifies commissioning by avoiding errors.
  • Eliminate false level readings during commissioning
  • Clean-out port enables internal inspection
  • Handle clearly indicates open or closed position of valve
  • Certifications for common applications
  • Lock-out / tag-out capability is standard
More information on this and related level gauge products is available from product specialists. Share your challenges with application experts and develop an effective solution by leveraging your own knowledge and experience with their product application expertise.

Wednesday, March 7, 2018

High Performance Butterfly Valves for Challenging Process Fluid Conditions

High performance double offset butterfly valve with actuator
High performance butterfly valves handle challenging
 media and process conditions.
Image courtesy Flowserve - Valtek Control Products
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 valve offering. Share and discuss your special requirements with a valve specialist. They have application experience and access to technical resources that can leverage your own process knowledge and experience into an effective solution.

Friday, February 23, 2018

Overview of Check-All Valve Manufacturing Check Valves



Check-All Valve manufactures in-line spring-loaded, piston-type check valves with metal to metal or soft seats. It is a single product company, specializing in only check valves for industrial use. The video provides a brief overview of the company, then continues with a more detailed description of the products and their defining capabilities and features.

Share your fluid control requirements with the fluid process experts at CTi Controltech, and leverage your process knowledge and experience with their product application expertise to develop effective solutions.

Sunday, February 18, 2018

Potential Application Problem Solved With Magnetic Level Indicator Design



Engineers, industrial process operators and stakeholders recognize the value and necessity of accurate and timely information from an operating process. Experience has shown that the environment and activities surrounding process installations and equipment can sometimes have a significant impact on the ability of measurement instrumentation continually gather and deliver accurate process data.

Concerns include:

  • Weather - An element whose impact cannot be understated....or easily predicted.
  • Physical Contact - Equipment and measurement devices must be protected from damaging impact.
  • Security - Vandalism, cyber invasion, and other external threats are possible

Our task is generally to effectively manage the operation of whatever processes are in place. Our responsibility, as operators of machines and handlers of materials that can produce hazardous or life threatening conditions in the case of failure or error, is to foresee every reasonably probable event that could affect the safe and proper operation of our industrial processes and mitigate or prevent their impact.

One manufacturer has developed an innovative solution to a potential problem in the application of magnetic level indicators. The short video below describes the conditions which could potentially result in instrument failure, and the way in which the product design change successfully overcomes any adverse impact on process measurement. Invest less than three minutes of your time to watch the video and build your application knowledge by learning from the experience of others. Do not hesitate to contact a product application specialist for more detail, or to discuss your process measurement needs.

Friday, February 9, 2018

Combustion, Emission, Steam, Valve, Automation and Instrumentation Solutions

chemical plant
Cti Controltech delivers process measurement and control
solutions across many industries.
CTi Controltech brings knowledge, experience and expertise to their customer relationships. We carry a broad range of process control, combustion and steam related products manufactured by globally recognized companies, along with the contracting and engineering resources to deliver complete solutions to customer challenges. CTi Controltech, located in Northern California, is a top flight provider of valves, valve actuation, emissions control and monitoring, industrial burners and boilers, pressure, temperature, level and flow instrumentation, custom SCR sytems, and steam management products. We craft solutions to the challenges our customers face everyday in process control.

Combustion, Emission and Steam Solutions
  • Low and ultra low NOx burners and burner retrofits 
  • BMS and CMS system design and hardware 
  • Custom design SCR Systems 
  • Burner air fuel mix recalibration 
  • Pre-emission test and boiler tune-ups 
  • Heat rate, efficiency studies and plant improvement 
  • Vapor recovery 
  • Particulate and CO2 control 
Valve and Automation Solutions
  • Severe service valve sizing and selection 
  • Valve and actuation packages, pneumatic, hydraulic and electric 
  • Noise and cavitation control 
  • Total valve management programs 
  • Turbine by-pass 
  • Desuperheating and attemperation 
  • Damper drives 
  • Check valves 
  • Vent to atmosphere and silencers 
  • Best fit for purpose replacement recommendations 
  • Ease of operation and life cycle cost considerations 
Pressure Relief
  • Rupture disc 
  • Pressure/Vacuum Relief Valves 
  • Pressure Relief Valves 
  • Vacuum Relief Valves 
  • Pilot Operated Valves 
  • Flame and Detonation Arresters 
  • Emergency Relief Valves 
  • Waste Gas Burners 
  • Pressure Regulators 
Instrumentation Solutions
  • Flow, level, pressure, density and temperature 
Services
  • Factory trained service personnel 
  • Commissioning and startup technical support 
  • Technical seminars and training 
  • Valve and actuator calibration and startup 
  • Instrument calibration and startup 
  • Complete turnkey project capabilities 
  • U.L. 508 custom design 
  • Project CAD drawings 
  • PLC Programming 
  • CFD and modeling 

Friday, February 2, 2018

Poppet Type Check Valves With Field Replaceable Insert

cutaway view of poppet type check valve disassembled view
This check valve, from Check-All Valve, has a single cartridge
interior that can be replaced easily in the field.
Image courtesy Check-All Valve
Check valves are employed throughout all types of fluid systems to prevent reverse flow. There are a number of styles or designs, each with attributes which determine its suitability for a particular application.

Check-All Valve is a USA manufacturer producing a broad selection of check valves for industrial use. Their EPIC™ series of poppet style valves deliver a number of solid features.

  • In-line spring loaded poppet type valve
  • Function in any flow orientation
  • Smooth contoured surfaces in flow path
  • Minimum change in flow direction through the valve
  • Minimized pressure drop
  • Complete drop-in replaceable insert for easy service
  • Quiet operation
  • Quick and smooth operation
The check valves are available in male and female pipe connections, as well as double ferrule and flared tube. The valves are suitable for liquid, gas or steam application with sizes ranging from 1/8" to 1-1/4".

Share your fluid system piping and control requirements with specialists. Leverage your own knowledge and experience with their product application expertise to develop the best solutions.



Friday, January 26, 2018

Pressure and Vacuum Relief Valves

schematic of processing or storage tank venting system
A pressure/vacuum relief valve is part of a complete tank
control system.
Image courtesy Groth Corporation
Storage or processing tanks are a part of almost any industrial liquid processing operation. There are many considerations for the inclusion of a tank in a liquid handling system. One facet, the subject of today's post, is how to accommodate the normal exchange of balance between liquid filled space and non-liquid filled space in a tank as it is filled or drained. Vacuum and pressure relief valves are, in many cases, the best solution for tank venting.

Keeping in mind that some tank involved operations process liquids that must remain isolated or contained from the atmosphere for any of a number of reasons. The tank may be blanketed with nitrogen or another gas. The contained liquid may produce vapor which cannot be freely vented to the atmosphere for regulatory reasons. Whatever the reason, one thing is common among all these applications. The tank must remain a closed system whenever its level is not changing.

When the liquid level in a closed tank changes, the pressure of the air or vapor in the tank will also change. Filling of the tank will increase the pressure, draining will decrease it. It is necessary to offset the change in pressure to avoid tank structural damage or processing difficulties from excessive positive or negative pressure produced by the changing liquid level. Groth Corporation manufactures pressure and vacuum relief valves for processing and storage tanks. Quoting from their installation manual for pressure/vacuum relief valves...
Pressure and/or vacuum relief valves are used on liquid storage tanks and other process vessels or systems to prevent structural damage due to excess internal pressure or vacuum. Storage tanks are pressurized when liquid is pumped in, compressing the existing vapor or when rising temperatures cause increased evaporation or expansion of existing vapor. Conversely, a vacuum condition may be created when pumping out or due to falling temperature. To prevent tank damage, vapor must be allowed into or out of the tank at specified pressure/vacuum conditions. The volume rate of venting depends upon the tank size, volatility of the tank contents, the pumping rates and the temperature.
These valves have specific requirements for installation and maintenance, but their operation is simple. A weighted pallet will move by gravity to a closed position when the liquid level is static. As liquid level changes and the pressure applied to the pallet changes, it will eventually move. It is important to note that each valve is weighted for the customer's specific application, and weight factory applied to the pallet should not be modified or otherwise changed without consulting the valve manufacturer to confirm the new operating parameters.

A pressure/vacuum relief valve is not intended to be a safety valve. It's function is related to the normal operation of the tank. A safety relief valve is an additional component with differing operational requirements. Here is now Groth describes the basic operation of the pressure and vacuum relief valves, with a little editing.
Pressure Relief: As the pressure in the storage tank increases, the vacuum pallet is held shut. When the set pressure is reached, the pressure pallet lifts and relieves tank pressure to the atmosphere (or to a header if it is a pipe away valve). 
Vacuum Relief: As a vacuum is drawn in the storage tank (for example, when fluid is being pumped out), the pressure pallet is held shut. When the vacuum setting is reached, the vacuum pallet lifts and air is drawn into the tank from the atmosphere.
Selecting and specifying a properly sized pressure/vacuum relief valve requires consideration of all aspects of tank operation. Share your project requirements with a product application specialist and leverage your own process knowledge and experience with their product application expertise to develop the best solution.

Friday, January 19, 2018

Flowmeter Basic Considerations

Multivariable flowmeter transmitter mass flowmeter flow temperature pressure
This multivariable vortex flowmeter provides output
of temperature, pressure and flow.
Image courtesy Azbil N.A.
Flow measurement, the quantifying of a point passage rate for gasses and liquids, is used throughout process applications in power generation, chemical manufacturing, petrochemicals, pulp and paper, water and wastewater, bio-science, semiconductor and many other manufacturing processes. There are two measurements of fluid flow in use: volumetric and weight or mass.

Flowmeters are used to measure the rate or quantity of fluid flow in an open or closed system. They are frequently found installed on piping systems, though there are also instruments capable of measuring liquid flow in open channels. The various measurement technologies have differing installation criteria, with some requiring placement of a sensing element in the flow path, others merely in contact with the flow medium, and still others with no media contact needed at all.

Flow measuring devices can be categorized in a few ways:
  • Inferential Types: Such as variable area flowmeters (rotameters), target flow meters and turbine flow meters.
  • Electrical Flow Meters: Such as electromagnetic flow meters, ultrasonic flowmeters and laser doppler anemometers.
  • Mechanical Type: Such as orifice plates, venturi tubes, flow nozzles, pitot tubes, positive displacement meters and mass flow meters.
  • Other: Such as vortex shedding flow meters, Coriolis, cross-correlation flowmeters, purge flow regulators, flow meters for solids flow measurement and flow switches.
Flow measurement instruments can be integrated into existing fluid transfer systems or installed on new lines, either inline or via insertion. Inline flowmeters mount in the piping system using downstream and upstream connections. Immersion flowmeters use a probe or sensor penetrating the piping, positioning the sensor in the flow stream.

For best results, it is important to heed manufacturer recommendations for installation. There are various flow characteristics that may have an adverse impact on measurement accuracy. Providing flow conditioning structures or maintaining minimum required straight runs on the upstream and downstream piping may be a requirement for some instruments. Each measurement technology will have installation recommendations and limitations.

For proper selection criteria, you should always know the physical state of the process media (solid, liquid, gas, steam), the condition of the media (clean, dirty, viscous, corrosive, flammable), piping size and range of flow rate. The process pressure and temperature can have an impact, as well.

Share your flow measurement challenges with a process measurement specialist and leverage your own knowledge and experience with their product application expertise to develop an effective solution.


Thursday, January 11, 2018

Sanitary Tank Bottom Valve

two-way sanitary tank drain valve cutaway view
Cutaway view of specialty ball valve configured as a
tank bottom valve.
Image courtesy PBM Valve Solutions
PBM Valve Solutions manufactures a special ball valve adaptation that functions as a drain valve, or bottom valve, on sanitary process tanks. This is just one of many specialties from the company that provide the perfect solution for targeted application challenges in fluid processing.

The IGENIX® two-way valve has a formed inlet pad that facilitiates drainage and minimizes the pocket area above the ball. The full size port and several other features accommodate the needs of sanitary process operations.

More information is provided in the cutsheet included below. Share your fluid process challenges with the specialists at CTi Controltech, leveraging your own knowledge and experience with their product application expertise to develop an effective solution.


Friday, January 5, 2018

Vortex Flowmeters

multivariable vortex flowmeter with temperature and pressure compensation
This vortex flowmeter combines, volumetric flow,
temperature and pressure measurement into a single instrument.
Image courtesy Azbil, N.A.
Vortex shedding flowmeters provide consistent process fluid flow rate measurements across a wide range of applications. These flowmeters measure the volumetric flow rate of steam, gas, and low viscosity liquids, boasting both versatility and dependability when used in conjunction with process control systems.

Vortex shedding refers to the phenomenon wherein flowing gas or liquid forms vortices around a solid obstruction placed in the flow path. The measurement technology returns an indication of the process fluid velocity, which can then be used with other data to calculate volumetric or mass flow. Vortex technology is well suited for many applications involving cryogenic liquids, hydrocarbons, air, and industrial gases. Vortex flow measurement does require contact between portions of the measurement instrument and the process media, so these flowmeters are commonly fashioned from a range of corrosion resistant materials. Compatability between the instrument construction materials and process media must be considered for every application.

The process of measuring the flow involves both the flowmeter and the ability for other instrumentation to measure the vortices themselves in order to calculate velocity. Ultrasonic sensors have become popular tools for measuring vortices. Applications involving flow measurement of high viscosity fluids are not well suited for vortex technology because extremely viscous fluids do not behave in the same manner as lower viscosity fluids when their flow path is obstructed. Splitting higher viscosity fluids into concordant vertices is extremely difficult due to the internal friction present in highly viscous liquids.

Additionally, in order to split these process liquids, the piping through which the process material flows must be straight, and disturbance or vibration in the pipe may impact the measurement. A vortex flowmeter will be in a fixed installation. This stationary element, operating without electrodes, can be advantageous for flow measurement in chemical applications utilizing low viscosity fluids.

The vortex shedding flowmeter is widely used for the measurement of steam flow. The high pressure and elevated temperature of steam, along with the variation that exists in most steam systems, have little negative impact on the operation of a vortex flowmeter. Vortex shedding flowmeters are volumetrically based in terms of measurement, but their output can be combined with other fluid measurements and data to calculate mass flow. A product variant commonly available will combine the vortex flow measurement with temperature and pressure compensation, delivering three process measurements from a single installed device.

Whatever your flow measurement challenge, share it with process measurement specialists and leverage your own knowledge and experience with their product application expertise.