Showing posts with label metal seat. Show all posts
Showing posts with label metal seat. 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.


Thursday, March 9, 2017

Metal Seated Ball Valves Offer Potential for Long Term Cost Savings

3 piece ball valve with handle
Adding metal seats to a ball valve can extend its service life
Photo courtesy of Flo Tite
The majority of ball valves are provided with one of several elastomeric materials forming a soft seat between the trim, or ball, and the valve body. With the balance of the valve assembly in contact with the media likely to be metal (unless, of  course, it is a plastic valve), the soft seat, because of its properties and location, tends to experience wear and tear and be a common cause for repair or valve performance deterioration.

In fluid process control applications where the media conditions may not, at first glance, warrant the use of a metal seated valve, there may be long term returns to be gained from the added cost of metal seats. The factors that create wear and degradation of soft seats are generally better tolerated by metal seats. Process downtime or man-hours for repair have a cost, so avoiding or reducing the occurrences of repair or maintenance provide a return on the additional expenditure for a metal seated valve that can provide a longer service life.

Many commonly available ball valves are also available with metal seats as an option, or metal seated variants are offered as uniquely identified products. Whatever the case, consider hardening your valve selections with metal seated valves. There are instances where they are well suited to the application and will offer a return on the additional cost.

Share your fluid process control challenges with a valve specialist, combining your own process knowledge with their product application expertise to develop effective solutions.



Tuesday, August 30, 2016

Applications For Metal Seated Ball Valve

metal seated ball valve with handle and flange connections
Metal Seated Ball Valve
Crane - Krombach
Fluid process control employs valves of various types to start, stop, throttle, or divert flow of a fluid. Ball valves are a common selection for process application when their inherent advantages provide the greatest benefit.
  • Leak-proof service
  • Well suited for processes requiring only full flow or no flow operation.
  • Rapid open and close action, requiring only 90 degrees of rotation from fully open to fully closed.
  • Comparatively light weight and compact size.
  • Wide range of construction material options for body, ball, and seals make them suitable for many applications.
  • Require only moderate force to control valve position.
  • Flow path opening in the ball will often be “full port”, providing same cross section as the connected pipe and adding very little restriction or pressure drop to the flow.
  • Low maintenance, with no lubrication required.
There are numerous ball valve variants that provide modified features and performance, but let's focus on what is generally considered severe service applications.

Severe service, while not currently defined by an international standard, generally can be characterized by one or more operating conditions that put great levels of stress or wear on valves.
  • Very extreme media or environmental temperature
  • High pressure drop operation that may cause cavitation
  • Rapid and extreme changes to inlet pressure
  • Certain types or amounts of solids contained in the fluid
  • Corrosive media
Some of these conditions will greatly impact the valve seat. Many valves are provided with thermoplastic seats that, while providing suitable performance throughout a wide range of media conditions, will deteriorate quickly under conditions prevailing in severe service. An alternative to the soft thermoplastic seats is a metal seat design. 
  • Greater temperature tolerance
  • Self cleaning seat
  • Improved resistance to effects of particulate laden media or slurries
  • Corrosion resistance, enhanced by special coatings applied to metal construction
The document below provides an in depth view of a metal seated ball valve. Operating conditions, specifications, and illustrations (including my favorite, the cutaway view) are provided. Share your fluid control requirements with product and application specialists, combining your process expertise with their product application knowledge to develop effective solutions.


Thursday, February 26, 2015

High Performance Butterfly Valve Seating Principles - Metal Seats

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



PRINCIPLE OF METAL SEATING



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.

Sunday, August 10, 2014

Introduction to Ball Valves

blaa valve
Trunnion type ball valve
Industrial ball valves are among the most cost-effective and most widely used type of industrial valve. A ball valve is a quarter-turn rotational motion valve, that uses a ball shaped disk to stop or start flow thorough the valve. When ball valve is opened, the ball rotates such that the hole through the ball is in line with the valve body inlet and outlet. If the valve is closed, the ball is rotated so that the hole is perpendicular to the flow openings of the valve body and the flow is stopped.

The basic design of a ball valve is similar to that of a plug valve. Instead of a plug though, a ball valve uses a spherical ball sandwiched between two sealing rings in a the valve body. This ball has a hole to allow the fluid to flow through. When the valve is closed, isolation is provided by the sealing rings and the solid side of the ball.