Posted by David g on November 08, 2019 at 15:12:23 from (209.181.208.169):
I was working at the natural gas interconnect on erratic flow readings.
This pipeline can handle up to a billion cubic feet per day at about 800 PSI.
We replaced the meters and the valve this summer, but we were not allowed to run the flow up and test. Well they ran the flow up last week and the readings were erratic, so they called me. The control system is tuned to respond with what is determined to be an equal response to what changes in the process, this keeps it in balance. On these, we typically control the flow and "override" or limit to prevent over pressure. We got lucky and they let us crank up the flow to test. I found that it would become erratic when the valve opened more than 25%, and would settle back down when it closed.
Well, it took me back to my schooling. A ball valve opening is not linear, the biggest changes happen when the valve nears the 50% mark and diminish towards the ends. I detuned the response from the controls and it settled right down and worked correctly.
There were two contributing factors to this. First and foremost the insides "trim" of the new valve were not the same size as the old one, which caused much more response to the process when we changed it a certain percentage than the old one. The second factor was that we did not get to test over the full range of control before handing it off to operations. It is not tested unless it is fully tested.
Upload one or more videos to your post. Photo and video filesizes should be less than 5MB. Formats allowed are gif, jpg, png, ogg, mp4, mov, and avi. Be sure to use filenames without spaces or special characters, and filetypes of 3 digits lower case.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Hydraulics - Cylinder Anatomy - by Curtis von Fange. Let’s make one more addition to our series on hydraulics. I’ve noticed a few questions in the comment section that could pertain to hydraulic cylinders so I thought we could take a short look at this real workhorse of the circuit. Cylinders are the reason for the hydraulic circuit. They take the fluid power delivered from the pump and magically change it into mechanical power. There are many types of cylinders that one might run across on a farm scenario. Each one could take a chapter in
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
