Re: [PipingDesign] Strainer Mesh size

Dear Bruce,

Thanx for your comments. Yeah my concern was also w.r.t pressure drop. Mechanical Strength is also factor, but as I have mentioned Mesh/Screen is already installed with same spec. Of course vendor is offering stronger structure Screen but it will add pressure drop and that's is my concern. Fluid service is cooling water and strainer is installed on 40" suction line of centrifugal Pump.

Regards.

Hafiz Ali Alvi
JGC-Descon Engineering
Pakistan

From: bbullough@foth.com
Sent: Tuesday, January 06, 2009 2:07 AM
To: PipingDesign@yahoogroups.com
Subject: Re: [PipingDesign] Strainer Mesh size

as per the Spirax Sarco information, the perforated plate is used to support the mesh screen. The the size of the holes in the perf plate is not crucial to the operation of the screen, except it does add some pressure drop. It has virtually nothing to do with the sizze of particles retained (or rejected, depending on your point of view) by the mesh screen. Taylor series 20 mesh has an opening of 0.841 mm, to allow only particles of smaller than 841 microns to pass. If the existing plant has 11 mm perf plate or 15 mm perf plate, there is nothing there that will change the particel retention size of the mesh. The 8 mm perf plate may have greater mechanical strength than the 11 mm or 15 mm plate in the existing installation. What you want to do is maximize the open area of the support perf plate, without compromising the mechanical strength. 8 mm perforations on a pitch that allows for greater open area may be exactly what you want.

... Bruce D. Bullough ...
Sr. Technical Consultant
Foth Companies
8550 Hudson Boulevard North, Suite 100
Lake Elmo, MN 55042
Phone: (651) 288-8598 Fax: (651) 288-8551 cell: (651) 269-1514 http://www.foth.com

IMPORTANT NOTICE
This communication including any attachments, (E-mail) is confidential and may be proprietary, privileged or otherwise protected from disclosure. If you are not the intended recipient, please notify the sender, permanently delete this E-mail from your system and destroy any copies. Any use of the E-mail, including disclosure, distribution or replication, by someone other than its intended recipient is prohibited.

This E-mail has the potential to have been altered or corrupted due to transmission or conversion. It may not be appropriate to rely upon this E-mail in the same manner as hard copy materials bearing the author's original signature or seal.

<alimalvi300@hotmail.com>
Sent by: PipingDesign@yahoogroups.com
01/05/2009 10:49 AM
Please respond to
PipingDesign@yahoogroups.com

To
<pipingdesign@yahoogroups.com>
cc

Subject
[PipingDesign] Strainer Mesh size

Hello,

My question is about 40" size Y-Type strainer installed on cooling water pump suction line. On data sheet filtering element is defined as 20 mesh. But vendor is offering 8 mm perforation + 20 mesh. From existing plant we got information that perforation hole dia is 11 mm with square pitch or 15mm. Now I am confused between 8mm perforation and 20 mesh screen. Because we can't place 8mm hole in 20 mesh screen. Please clarify if any one have idea about it.
I read on spirax sarco website perforated screen is used to support wire mesh cage.

Regards.

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]
Received on Tue Jan 06 13:02:00 2009