Re: [foxboro] flow meter

From: dirk.pauwels@xxxxxxxxxx
To: foxboro@xxxxxxxxxxxxx
Date: Mon, 2 Feb 2009 08:05:41 +0100
Many thanks to all who replied on this topic....the guy who told me it
would only work with pulse is now hiding under his desk......

Rgds,

Dirk Pauwels - DCS/MOC coordinator
Engineering dept.
Hexion Specialty Chemicals
E mail: dirk.pauwels@xxxxxxxxxx
T.  +32.(0)3.570.95.97
F.  +32.(0)3.570.16.09
Mob. +32.(0)497.428.300


                                                                           
             "Jeff Blair"                                                  
             <jblair@meadobrie                                             
             n.com>                                                     To 
             Sent by:                  <foxboro@xxxxxxxxxxxxx>             
             foxboro-bounce@fr                                          cc 
             eelists.org                                                   
                                                                   Subject 
                                       Re: [foxboro] flow meter            
             30/01/2009 20:54                                              
                                                                           
                                                                           
             Please respond to                                             
             foxboro@freelists                                             
                   .org                                                    
                                                                           
                                                                           




When looking for a flowmeter, I would always consider a HART protocol
with the 4-20mA output.  This allows technicians easy configuration of
the meter using a 375 HART communicator.  There are some extra process
details that HART allows you to download (i.e. temp of electronics).

Foxboro has a good initial tool for flowmeter selection online at
www.flowexpertpro.com

Don't overlook vortex as a possible solution.

Best regards,
Jeff Blair
Mead O'Brien, Inc.

-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx]
On Behalf Of Badura, Tom
Sent: Friday, January 30, 2009 1:24 PM
To: foxboro@xxxxxxxxxxxxx
Subject: Re: [foxboro] flow meter

Dirk,

We went the same route a number of years ago.  We started replacing load
cell pre-weigh scale tanks with flow meters for our batching
applications. Corey is correct that you should have a variety of meter
technologies to choose from that will offer a 4-20mA signal.  The fact
that you call the fluid an oil makes me think it is non-conductive and
viscous which means it won't work with a magmeter and may not have a
fully developed turbulent flow profile to work with D/P or vortex
shedding meters.  The fluid should work well with either ultrasonic or
positive displacement meters or coriolis or thermal dissipation meters.
Ultrasonic and PD are volumetric meters which will work fine if you only
need volume or if your fluid remains constant so you can infer mass.  PD
meters are inherently a discrete (pulse / volume) device but most offer
electronics to convert to 4-20mA.  The coriolis and thermal dissipation
are true mass flow meters.

I believe coriolis meters can have the best true mass batching
performance; however, they are also the most expensive and do need to be
installed and operated correctly.  They are inherently susceptible to
air or gases entrained in the process fluid that can cause inaccuracies
or the meter to stop working altogether (this will affect the other
technologies as well).  Does your process start or end on an empty pipe
condition?  Can the fluid flash in the pipe?  It is also possible for
fluids to decrease to their vapor pressure at high elevations and/or in
heated pipes during no flow conditions.  Potential air leaks such as
pump or valve seals can also create a problem.  They are also big and
heavy and the pipe line must be supported properly and can be affected
by vibration.  With that said we have used Foxboro coriolis meters for
critical batching operations for the past 10-15 years with good success.
They have been very reliable and are very maintenance free if you did
your homework upfront. (Yes, we worked through most of the issues that I
have pointed out).  They have now introduced a model that can function
with and compensate for entrained air.  We have recently installed one
of these units on a truck unloading application and so far it performs
as advertised; however, there was some loss of accuracy when operating
with a significant amount of air (as would be expected).  We communicate
digitally with our I/A system (we use Foxcom), and the additional
measurements (temperature, density) can be beneficial.  We have also
used magmeters, vortex meters, and PD meters for volumetric totalizing
and batching applications with good success.  Again, following the
manufactures installation requirements and maintaining a full pipe and
flow meter is essential.

One other thought -- many flowmeters also offer a built in totalizing
(batching) function.  In some cases this can be beneficial or more
convenient and even more accurate than totalizing in the control system.
It may even be possible to utilize the built in totalizer via the DCS
especially if you are able to communicate with the flowmeter.

Hope some of this may be of help to you.

Tom Badura
Plastics Engineering Company
920-458-2121 x3366
tbadura@xxxxxxxxxx




-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx]
On Behalf Of Corey R Clingo
Sent: Friday, January 30, 2009 10:44 AM
To: foxboro@xxxxxxxxxxxxx
Subject: Re: [foxboro] flow meter

Yes, same here.  All our flowmeters have 4-20mA outputs.  The pulse
outputs are either secondary or options, and we haven't used them except

occasionally in standalone batching systems (the flow computers for the
batching usually take a pulse input).

Depending on the characteristics of your oil and the flow rate, you
might
be able to use any of dP, vortex, thermal dispersion, coriolis, or
ultrasonic measurements.  Magnetic is probably not an option unless the
oil has impurities that raise its conductivity.  In any case, meters of
all those types from well-known, reputable vendors have 4-20mA outputs.


Corey Clingo
BASF Corporation






dirk.pauwels@xxxxxxxxxx
Sent by: foxboro-bounce@xxxxxxxxxxxxx
01/30/2009 10:03 AM
Please respond to
foxboro@xxxxxxxxxxxxx


To
foxboro@xxxxxxxxxxxxx
cc

Subject
[foxboro] flow meter







Hi guys,

Just wondering if any of you are using flowmeters in your piping and
which
type you have good experiences with. We're thinking on installing a
Flowmeter in an oil header. We haven't got flowmeters for the moment,
our
products usually are not suited for flowmeters. Except for the oil
headers.
We usually work with loadcells but for this project we would need a
flowtransmitter.
Problem seems to be these flowmeters don't transmit 4-20 ma but pulses.
Our
DCS can't handle the number of pulses per second, so we'll need a
seperate
controller. Are there any flowmeters (2" pipe) that transmit 4-20ma?

Thanks & Rgds

Dirk








_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html

foxboro mailing list:             //www.freelists.org/list/foxboro
to subscribe:         mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe:      mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave



_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html

foxboro mailing list:             //www.freelists.org/list/foxboro
to subscribe:         mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe:      mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave



_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html

foxboro mailing list:             //www.freelists.org/list/foxboro
to subscribe:         mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe:      mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave



 
 
_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html
 
foxboro mailing list:             //www.freelists.org/list/foxboro
to subscribe:         mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe:      mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave
Re: [foxboro] flow meter

Other related posts:
