March 22, 2007

Valve Design and Materials are Questions addressed in Hot Topic Hour March 22

The valve Hot Topic discussion was definitely global with Patrick Heller participating from Australia and Werner Kremer commenting from Germany. The five presentations were crammed with good information and substantial differences in point of view. You can view the power points of the presentations from the links below.

 Particulate Decision Tree

Tyco-Goyen – Patrick Heller

Patrick Heller talked about the special use diaphragm valves to clean fabric filter dust collectors. Pulse air is used for cleaning. The blowtube is an extension of the valve. Pipe design should have balanced pressure. More plants are running at lower header pressure and they are cleaning more cloth area per valve. Both trends point to use of larger valves to deliver necessary pressure. There are many design considerations which will result in lower power consumption for a given quality of cleaning. Bag life extension is another important parameter.

Continuing Decision Process For: Products

Reverse pulse jet valves for fabric filter dust collectors in CFB power applications.

http://www.mcilvainecompany.com/Particulate_Decision_Tree/subscriber/Tree/DescriptionTextLinks/Pulse Systems for CFB.htm

FGD Decision Tree

ITT Engineered Valves – Dan Ellis

Dan Ellis discussed the various possible valves that could be included in FGD units. He felt that the rule of thumb would be that any slurry greater than five percent should use a knife gate valve because of its positive shut off and long term use. Below five percent a ball, plug, butterfly or diaphragm could be used. A cost saving possiblity would be to use pinch or diaphragm for smaller valves instead of using a knife gate. Control valves would be best using diaphragm or ceramic ball valves.

Continuing Decision Process For: Products

Slurry Valve Selection for Wet FGD

http://www.mcilvainecompany.com/FGD_Decision_Tree/subscriber/Tree/DescriptionTextLinks/FGD valve selection ITT.htm
 

Larox – Todd Loudin

Todd Loudin stated that Larox has, in the last 12 years, been selling pinch valves to replace knife gate valves in FGD units. He gave an example of the St. Johns River Power Plant that has replaced over 100 knife gate valves successfully with rubber lined pinch valves. The valves can be constructed in polycarbonate making the valve lighter.

Continuing Decision Process For: Products

FGD Scrubber Installation

http://www.mcilvainecompany.com/FGD_Decision_Tree/subscriber/Tree/DescriptionTextLinks/FGD Scrubber Installation Presentation - Larox.htm
 

Crane Valves – Werner Kremer

Werner Kremer discussed the wet FGD process which can have 350 to 600 valves. Valves have to be built to prevent corrosion and abrasion. Valves should reduce the amount of valve in contact with the wet products. Those parts in contact with wetted solutions should be made of Hastelloy, Duplex, and Hostalen GUD, a process developed by Crane. The first power plant with Hostalen was in Turkey in 1994.

Continuing Decision Process For: Products

Valve Selection for Power Plant FGD and Other Air Quality Systems

http://www.mcilvainecompany.com/FGD_Decision_Tree/subscriber/Tree/DescriptionTextLinks/FGD_Valve Selection PPTminimizer.pdf

Tyco Valves – Darrel DesRochers

Darrel DesRochers said Tyco has found that flow rates in piping systems for FGD units should stay below eight feet per second for best results. Conventional valves in slurry service tend to clog and leak. Conventional knife gate valves can clog, then the gate is subject to media and solids collect in ports. He also discussed other types of valves and their disadvantages and advantages. Clarkson slurry valves have rubber sleeves, gates outside the flow, and positive cycle. Clarkson valves range from three inches to 60 inches. 

Continuing Decision Process For: Products

Clarkson Valves in Wet FGD

http://www.mcilvainecompany.com/FGD_Decision_Tree/subscriber/Tree/DescriptionTextLinks/FGD Clarkson McIlvanie Presentation Part 1.htm
 

FGD Systems with Clarkson Slurry Valves

http://www.mcilvainecompany.com/FGD_Decision_Tree/subscriber/Tree/DescriptionTextLinks/FGD Clarkson McIlvanie Presentation.htm