Showing posts with label high performance butterfly valve. Show all posts
Showing posts with label high performance butterfly valve. Show all posts

Thursday, January 25, 2018

Krombach Brand Valves for Rugged Service Conditions

metal seated butterfly valve with actuator
Metal seated butterfly valves for aggressive process
applications are a hallmark of the Krombach brand.
Image courtesy Crane CPE
The Krombach branded valves, part of the Crane CPE product offering, target challenging applications in industrial settings that benefit from the use of valves specially designed for severe service. The brand also includes a standard product offering of valves and specialties for a broad range of common industrial applications.

The Krombach line includes:

  • Butterfly Valves - High performance, resilient seated, double-eccentric, triple offset and special purpose butterfly valves.
  • Ball Valves - Process one-piece, two-piece and three-piece, metal seated, soft seated and compact ball valves.
  • Globe and Angle Valves - Bronze, cast iron, cast steel and stainless steel globe and angle valves.
  • Gate Valves - Bronze, cast iron, cast steel and stainless steel gate valves.
  • Check Valves - Ball, dual-plate, foot, full body swing, steam stop, tilting disc, wafer style swing, nozzle-type and pressure seal check valves.
  • Vacuum Relief Valves - Available with flanged or threaded connections.
  • Aerating and Deaerating Valves - Essential for trouble-free operation of pipeline systems handling liquids.
  • Float Valves - Single seated and double seated versions for a variety of applications.
  • Throttle Valves - Available with flange connection, wafer- or weld-in type.
  • Bottom Drain Valves - Available manually operated or with a diaphragm actuator.

Below is a cutsheet providing an overview of the company's standard product categories. Whatever your fluid control application, share your challenges with the valve specialists at MSEC. Leverage your own process knowledge and experience with their product application expertise to develop effective valve and automation solutions.

Monday, September 28, 2015

Triple Offset Valves - Some Advantages and Considerations

Flowseal brand triple offset butterfly valve
Triple Offset Butterfly Valve
Courtesy Flowseal, Crane CPE
Industrial process control often involves the control of fluid flow, ranging from slurries or petroleum to highly refined liquids and gases. The enormous variety of application specifics has given rise to a wide range of valves with performance characteristics to match those requirements. One common valve type is the butterfly valve. In it's simplest form, it is a disc located in the path of fluid flow that is connected to a shaft. The disc rotates through a 90 degree arc to present either its face (valve closed) or its edge (valve open) to the fluid flow path. I wrote about some advantages and disadvantages of butterfly valves a couple months ago under the title "Is a Butterfly Valve Right for Your Application?".

There is a variant of the simple version of the butterfly valve that provides distinct advantages for many applications. Referred to somewhat officially as a triple offset butterfly valve, it can also be more commonly called simply a triple offset valve.

How is a triple offset butterfly valve different from a basic butterfly valve?

The triple offset valve does away with the centric alignment of the shaft and disc, using instead a shaft mounting arrangement that relocates the shaft axis off both the center of the disc and the center of the bore. This shaft positioning, while creating a larger flow obstruction in the fully open position, sets the disc movement path in the proper alignment to take advantage of the third offset, which is the sealing surface. Triple offset valves have a different seals than other butterfly valve variants. There is an angular sealing surface, the angle of which is determined by sectioning an imaginary right angle cone shape that extends along the bore. However, the apex of the cone does not lie on the center of the bore. This inclination of the seal cone constitutes the third offset. You can see an illustration of this description in the document included below.

What advantages might those differences bring to your application?

  • Triple offset valves have discs that do not contact the sealing surface until the valve is closed. This is in contrast to other butterfly valve designs, which have contact between the disc and resilient seals for part or all of the disc travel, along with the associated friction and wear.
  • Elastomer or other similarly resilient materials are not needed to provide a zero-leakage, bubble tight shutoff. Sealing is generally accomplished with metal-to-metal contact.
  • Friction free stroking of the valve disc. Actuator power requirements may be reduced.
  • All metal construction provides elements of corrosion and heat resistance not found in other butterfly valve designs with resilient seals.
  • This valve is torque sealed, not position sealed like other butterfly variants. Actuator torque forces the seal of the machined metal surfaces to produce tight shutoff.
  • No breakaway torque requirement, since the disc is not contacting resilient seals. 
  • Seating arrangement prevents overstroking of the valve, a potential problem with other butterfly valves.
Different manufacturers may have slightly different feature sets, but this should help you consider the benefits of this butterfly valve variant. Though its initial cost may be higher, the expected lower maintenance requirement, longer service life, and better performance may be well worth it. Talk to a valve product specialist about your application. I've written many times that combining your process expertise with the up to date product knowledge of a professional sales engineer will produce a positive outcome.

Tuesday, July 14, 2015

Is a Butterfly Valve Right for Your Application?

There are many manufacturers of industrial control valves, with each producing an array of sizes, types, construction materials, and other distinguishing characteristics that make it necessary to quickly narrow the field of contenders to consider for your valve application in order to be productive. A useful filter that can be applied to the broad offering of valves is selecting a valve “type”. Valve types are generally classified according to their means of closure, with some common types being ball, plug, globe, butterfly and gate, among others. Each type has particular application strengths, some that may prove advantageous enough for your application to exclude all others. Let’s take a look at butterfly valves.
industrial butterfly valve
Butterfly Valve
Courtesy Crane CPE

The closure means for a simple butterfly valve is a disc, positioned in the fluid flow path, that rotates around a central axis through a 90 degree arc. The valve stem serves as the axis and extends through a seal to the exterior of the valve body where it serves as an actuation point. The closed position for the valve has the disc positioned perpendicular to the direction of flow and blocking the flow path. When open, the disc is parallel to the flow path, but still positioned in the center of the flow. Butterfly valves are available in a variety of construction materials, making them suitable for an array of media.

Butterfly valve aspects that might be advantageous:
industrial butterfly valve
Butterfly Valve
Courtesy Crane CPE

  • Closure mechanism allows for comparatively low torque operation.
  • Small size and weight for reduced installation space and valve body support.
  • Low pressure drop in the fully open position. The disc, when parallel to the flow path, presents a thin edge of its profile to the fluid flow.
  • Low maintenance requirements and small parts count.
  • Transition from fully open to fully closed with a 90 degree turn provides for fast operation.
  • Suitable for limited range of throttling applications.

Aspects warranting closer scrutiny:

  • Throttling capability is generally limited to low pressure drop applications.
  • The orientation of the closure may cause cavitation under some conditions.
  • Choked flow can be a concern under certain conditions.

Performance, low maintenance requirements, and cost are always primary considerations. There are many more detailed sources of application information. Consult with a professional sales engineer that specializes in industrial process valves and get the information you need to make a good choice.

Thursday, February 26, 2015

High Performance Butterfly Valve Seating Principles - Metal Seats

high performance butterfly valve
High Performance Butterfly Valve
(courtesy of Flowseal)


Metal-to-metal sealing is accomplished by the “line contact” between a spherical surface and conical surface. Figure 1 illustrates a typical globe control valve seat and plug. The plug seating surface is the segment of a sphere; when engaged against the seat ring, a line contact seal is achieved.

In a metal seat design, it is necessary to apply enough force per linear inch to maintain a tight metal-to-metal contact between the seal- ing members; however, high linear thrust can cause a collapse of the seating members (“bearing failure”).

DISC CLOSED, Self-Energized Seal

In Figure 2, the Flowseal disc and seat are engaged, and the process fluid is under low pressure. The spherical edge of the disc, with a larger diameter than the conical seat tongue, imparts a thrust of approximately 600 pounds per linear inch against the seat. The mechanical properties and shape of the Inconel® seat allow it to both flex and maintain a constant thrust against the disc.

This controlled loading prevents the occurrence of bearing failure and reduces the leakage and wear between the components.

Wednesday, February 25, 2015

High Performance Butterfly Valve Seating Principles - Soft Seats

high performance butterfly valve
High Performance Butterfly Valve
(courtesy of Flowseal)

High performance butterfly valves (HPBV) are a standard in many industries including heating, ventilating and air conditioning, power generation, hydrocarbon processing, water and waste water treatment, and marine and commercial shipbuilding.

They are also installed in applications as diverse as food and beverage processing, snowmaking and pulp and paper production. Configurations are available for harsh conditions as well as applications requiring nominal pressure and temperature ratings.

The following describes the soft seating design principles for high performance butterfly valves:

soft seated HPBV valve

In Figure 1, the disc and seat are not engaged. In this position, the shoulders of the seat are forced against the cavity shoulders by the compression of the o-ring.

The seat is recessed inside the seat cavity and acts as a gasket in the anchoring groove area.The seat cavity is sealed from exposure from the process fluid and protects the seat from abrasion and wear. The o-ring, which is completely encapsulated by the seat, is also isolated from exposure to the process fluid.

Tuesday, December 23, 2014

High Performance Butterfly Valve Exploded View

Here is a short video that quickly displays the components of a high performance butterfly valve. High performance butterfly valves are used in the oil and gas, commercial HVAC, chemical processing, mining, pharmaceutical, water & wastewater industries. High performance butterfly valves come in wafer and lug bodies, have bodies made of carbon steel, stainless steel, or other alloys, and work under higher pressures and temperatures than "rubber lined" butterfly valves.

Thursday, October 9, 2014

High Performance Butterfly Valves for On/Off and Throttling Service

High Performance Butterfly Valves (HPBF) are a standard in many industries including heating, ventilating and air conditioning, power generation, hydrocarbon processing, water and waste water treatment. The key features of HPBV are high performance shutoff and modulating service for standard industrial process lines, materials of construction options include carbon and stainless
steel,  sizes up to 48”, both wafer and lugged body styles available, in pressures classes 150 – 600.

Here is a short video introducing the Flowseal high performance butterfly valve.

Tuesday, July 8, 2014

Resilient Seated and High Performance Butterfly Valves

Lug Body Resilient
Seated Butterfly Valve
(Crane Centerline)

A butterfly valve uses a round, thin disk to control flow through a pipe. The disk is connected to the stem via a shaft completely through the disk, or at the top and bottom of the valve. 

The butterfly disk is continuously in the flow path, but because of its thin profile, has minimal impact on flow. Butterfly valves are popular because they offer very tight shut-off, are available in a wide range of materials and sizes, and can be automated inexpensively with many types of quarter-turn electric and pneumatic actuators.

Butterfly valves are used in many industrial applications today, from controlling the flow of water to handling much more severe industrial fluids. Butterfly valves are extensively used in water treatment, chemical processing, pulp and paper making, food processing, power generation and many other industries.