Showing posts with label duo-chek. Show all posts
Showing posts with label duo-chek. Show all posts

Monday, August 22, 2016

High Performance Non-Slam Check Valve

high performance dual plate check valve
Crane Duo-Chek dual plate check valve
Check valves are ubiquitous throughout fluid processing operations. These simple devices permit fluid flow in one direction only. While there are numerous design variants available in the marketplace, operation is very similar in all check valves. Fluid pressure and movement in the desired direction moves a plate, plug, ball, or other obstruction to a position that allows flow to pass. The plate or other obstruction has a design countervailing force applied to it by a spring, gravity, or some other means that will move the trim to the closed position. When pressure drop across the valve decreases below the design level, the trim will close. Fluid pressure exerted on the outlet side of the valve will maintain a closed position in the valve. In this manner, a check valve allows fluid to pass in one direction, but not in the reverse.

Beneficial features of a check valve would include some or all of the following:

  • Lightweight and compact design
  • Tight shutoff that meets any applicable standards
  • Low pressure drop when open
  • Operation that minimizes seal wear
  • Installation simplicity and flexibility
  • Easy to insulate
  • Low maintenance requirements
  • No slamming to the closed position
  • No valve chatter
  • Available in numerous configurations to meet wide range of applications
Share your fluid process control challenges with a product application specialist. Combine your process knowledge with their product application expertise for effective solutions.




Tuesday, October 14, 2014

Advantages of a Wafer Check Valve

wafer check valve
Wafer check valve
(courtesy of Duo-Chek)
A wafer check valve is an excellent choice for applications where water hammer, mounting space and flow restriction are issues.

A wafer check is designed to be "sandwiched" inline between two pipe flanges in the piping system, adding very little additional weight or bulk to the piping layout. Wafer checks overall tend to be stronger, lighter, smaller, more efficient and less expensive than conventional swing check valves and are easier to install between standard gasket and line flanges.

Along with being lighter, easier to install and store, wafer check valves also offer the following advantages:
  1. Disc travel is short with less impact force caused by valve closing.
  2. The disc closes quickly with less water hammer pressure. Water hammer pressure is only 1/2 to 1/5 times of flange type swing check valve and flange type lift check valve.
  3. Low flow resistance.
  4. Horizontal and vertical installation available.
  5. Very low opening (cracking) pressure differential.
  6. More reliable due to lower impact forces, less water hammer.
Wafer check valves are available in many sizes, typically from 2” to 72”, in ASME pressure classes 125 through 2500 and API 6A and 6D pressure classes. DIN, JIS, BS, AS, and ISO standards are also available. Body styles include wafer, lug, double flanged and extended body. Wafer check configurations are available in retainer-less style, wafer, extended body wafer and lined. Typical body materials are cast iron, ductile iron, WCB cast steel, 316 stainless steel and other alloys. Common seating materials are EPDM, Buna-N, Neoprene, Refrigeration-grade elastomer, and Viton. The most common end connections are raised face, plain face, ring joint, weld-end, as well as hub-end.