yes. Russell Ultrasound (JIM RUSSELL)here in alberta has developed such a pig
and I have done some work with and on it.
There is actually a whole array of pigs with amazing capability. (yes they can
"fly" - along the pipe)
They are pricey and generally the service is provided by a contractor. There are
many other pig manufacturers. Russell makes the best smart pigs but they are
overkill for your needs.
We've located stuck pig with a metal detector. The signal jumps way up as long as the pipe is less than a few ft below ground or A/G.
We have inserted slip liners that are soft "mushy" plastic when they go in and fold over themselves to form a sheath to the id of the pipe. The big operator was RNG but they went belly up but shouldnt be hard to find others on the web. This can be tricky and best to get the professional (expereinced installer) input on your installation.
al
Hi Geoff
We have a positive Langalier index so the line is scaling more than it is
corroding. At present there is a water shortage so I am reluctant to close
down the line too long, especially for condition assessment only.
After much head scratching, I think I will fit a booster pump part way up
the hill to restore flow, and then carry out the pigging operation when
water is more abundant.
Can you get a pig with an ultrasonic transmitter/receiver built in? If it
jams then we could locate it by signal transit time.
Whats the story about slip liners? Any websites that give a good intro?
Cheers
Steve
-----Original Message-----
From: Geoff Stone DD&D Australia [mailto:blenrayaust@yahoo.co.uk]
Sent: Thursday, September 11, 2003 9:53 AM
To: <a href="/group/PipingDesign/post?postID=D09vHccqfZ36goY_oxL_RP5D-iwidE69VISnNUEULUfA1XxSbe4VAtttx8nXJOgreYPmzvB9U-On0qAvHuMdEXw_hEA">PipingDesign@yahoogroups.com</a>
Subject: Re: [PipingDesign] Pig
Steve,
A risk analysis of this operation will drive you to find out more about the condition of the pipe before rushing in and pigging the line.
The problems with a steel line could be scaling, high levels of corrosion or
local blockage. Running an intelligent pig htrough a small section (uphill)
and
reversing it out(compressed air downhill) may give some idea as to the
problem.
Also you may be able to get a CCTV into places such as air valve or scour
valve
locations.
If you have scaling then you are looking at an acid clean short term and antiscalant dosing in the future.
If the line is heavily corroded you may be looking at sliplining this one to keep it going and running a parallel line to meet the flow required.
If pigging is required I would pig from the bottom but make sure that I had
to
hand compressed air to drive the pig in reverse. Also some good metering so
That I knew how much water had gone into the line before the pig got stuck.
Then a field crew could dig it up and make a repair.
Geoff
I am looking at having a portion of water supply line pigged out because its friction loss is around 4 times what it was. The line is 10" steel, 3/8" wall and is a rising main taking water from a pond to the top of a hill about 330m higher up. The pipe length is 3900m, reasonably constant incline (but a few level portions at road crossings) and currently flows at about 70 l/s. Line pressure at the bottom end is 44 bar and there is an atmospheric vent as the top end.
I have no experience in pigging and am unsure what the outcome will
be and the best way to do it.
My nightmare is blocking the line; I can take it out of service for a
few days, but longer than this would cost millions as it would shut
down a processing plant.
The pig supplier suggested going from the top to the bottom using
compressed air to force the pig down the line (there is no water
supply at the top of the hill).
The pigging contractor thinks going from the bottom to the top using
water to drive the pig up the line is the best way to go.
I can see pros and cons with both options, but am tending to favour
the water (uphill) option because of the flushing action of the water.
But what do I know?
Any experience or suggestions would be appreciated.
Cheers
Steve McKenzie
Yahoo! Groups Sponsor ADVERTISEMENT
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Overseas tel 61 2 402 35 2313 fax 61 2 8850 2313 mobile 0402 35 2313 Mail Address PO Box 1351 Castle Hill NSW 1765 Australia
Your use of Yahoo! Groups is subject to <a href="http://docs.yahoo.com/info/terms/">http://docs.yahoo.com/info/terms/</a>
Yahoo! Groups Sponsor
ADVERTISEMENT
========================================
Discussion List sponsor: The fluid flow calculations website - www.LMNOeng.com
- LMNO Engineering, Research, and Software, Ltd.
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed] Received on Mon Sep 15 19:51:00 2003
This archive was generated by hypermail 2.1.8 : Tue Mar 04 2008 - 11:40:29 EST