Best material to use for Water Inlet Screen? 2

[flatbottom]

Customer does not want to use stainless anymore. Something in the water chemistry is deteriorating the stainless. Is HDMW or HDPE a good choice for a screen that will be for the most part submerged underwater? Do I have to worry about hydrolysis with these materials? It could be any size panel....I have to cover a 8 foot wide by 24 foot high area.

 

[stanier]

These materials are unlikely to withstand the hydraulic loads from a choked screen. If corroson is of concern then select the correct grade of stainless steel. Super duplex grades are available that withstand super chlorinated sea water.

Alternatively you could use titanium or cupro nickel.

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

 

[bimr]

Screens can be constructed out of 304, 304L, 316L and 904L stainless steels.

Plastics are totally unsuitable for this application from strength of materials standpoint.

These screens are also made from self cleaning wire shapes that are not possible with plastics.

 

[stanier]

You can get the screens in duplex and super duplex materials. SAF 2304 and SAF 2205.

First check the water chemistry and then select the material. You may be able to find a screen manuafacturer who uses GRP. It depends on the screen aperture you are looking for. google wedge wire screeens sea water and see the supplier. Wedge wire can be in flat panels or circular screens.

http://www.carbisfiltration.co.uk/productsWWS.shtml

http://www.amistco.com/waterwell/industserved.html

http://www.federalscreen.com/

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

 

[flatbottom]

Thanks everyone...Customer is having the water chemistry checked and then they will recommend what type of stainless to use for the new screens. Thanks for the advice and links to manufacturers.

 

[QualityTime]

I don't know what type of water is being screened but I can offer a comment.

If the water is chlorinated, the moist chlorine fumes above the water level will attack SS screens.

Muncipal water treatment plants at one time used 304L stainless steel pipe and the exterior of the pipe was being attacked by the moist chlorine fumes in the air. The engineers then went to using 316L SS because it has a higher resistance to chloride attack. The key however is to make sure the 316L piping has a 2B finish. If you have piping that has a polished #4 finish, for example, the 316L SS will have corrossion resistant properties LESS than that of 304L!!! That is why you see POLISHED 316L SS electrical control panels rusting in water treatement plants!!!

 

[stanier]

"Stainless" is just that! It is totally stain resistant. If your stainless steel has rust stains then you need to clean it and re-passivate the surface. This process reforms the chromium oxide layer that provides the corrosion resistance.

I would alos be wary of electrical cabinets claiming to be made from 316L SS. Without a materials cetificate I would challenge that it wasnt in a lower corrosion resistance type. Material certificates are rarely asked for when it comes to cabinets.

I have seen a major equipment manufacturer supply mining equipment claiming it was 316 ss. Even he had certificates. When tested it turned out to be 304ss.

If it rusts and it should not then have the material tested and keep your lawyers phone number nearby.

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/