www.tdwilliamson.com April 2005 In This Issue: Archives Check out the past issues of our newsletters. Click Here FeedBack Have a suggestion, comment, or idea? Let us know about it. Click Here Contact Us! Subscribe Print Version Click the printer above to print out the text version of this newsletter. TDW Job-Site Solutions Visit TDW's Web site to learn more about how professionals in your industry have teamed up with TDW to solve their pipeline maintenance problems! Visit TDW Job-Site Articles HotTapsTDW.com PiggingTDW.com Your Source for Piping Solutions. TDW Offshore Services - Works with Surgical Precision Valves in a pipeline or piping system occasionally have to be replaced for various reasons. In most cases, the operator desires to keep the line in service while this work is performed. Such was the case with this operator. At the pipeline end of a 36-inch pig launcher are primary and secondary isolation ball valves, separated by a spool. The secondary valve needed replacement. These valves are a barrier to the 1600 psi (117 bar) pipeline pressure and are opened to launch or receive a pig. This launcher is on an offshore platform in the North Sea, 170 miles seaward from Aberdeen, Scotland. In order to keep the pipeline in service at its operating pressure, a backup barrier would be required. The TDW Offshore Services, based in Houston, Tx., was selected to provide this backup with its plugging pig tool, a tool that can be set at a precise position in a pipeline by remote control, stopping flow. The plug will have to be positioned in the spool between the valves with only a few inches to spare. Not only is the precise positioning critical, staying power is also a necessity. The valve removal and replacement operation will require 10 days. Figure 1 The tool selected was a special design, utilizing already-proven technology. It consisted of four basic components, packaged to meet the particular requirements of this job, and is shown in Figure 1: The control module contained the communications and hydraulic circuitry necessary to operate and activate the tool; the grip module, when activated, expanded against the pipeline wall, holding it in position; the packer module was compressed and expanded against the pipeline wall providing a seal; and the pigging discs used pipeline flow to propel the pig through the launcher to the correct position. The pigging discs were designed to allow the tool to move at a controlled slow speed without erratic movements as it was being positioned. A positioning device on the front of the tool provided precise positioning information. During final preparations, the TDW team ran numerous models of positioning solutions to determine the exact location on the spool to place the positioning device. These solutions were successfully tested to the client's satisfaction. This position would be monitored closely during movement of the tool and would be continuously monitored for movement during the valve removal operation. This function was also tested successfully to the client's satisfaction. This monitoring system would be critical to the client in two ways: 1) to ensure that the plug would not interfere with the primary valve or with the replacement of the secondary valve, and; 2) that the plug would be in the spool and could be continuously monitored to any movement for client safety assurances. Figure 2 The plug was inserted into the barrel of the trap, the trap filled and pressure tested. The valve to be replaced was opened fully and the primary valve opened 20 percent, creating a flow. Pressure in the launcher behind the tool was increased slightly above line pressure, moving the tool about three feet per minute. The positioning device on the front of the tool was tracked until it moved through the valve to be replaced and into final position in the spool. Once there, it took about 20 minutes to set the plug grips and packer seals, involving several hydraulic pump cycles. The TDW team decided to set the plug in steps to provide the client with assurance that "all was well" inside their pipeline. Pressure transducers connected to the hydraulic cylinder were continuously monitored to ensure that pressures were changing with each pump cycle. The plug is shown in Figure 2 in the set position. Pressures were monitored every 30 minutes for the next 12 hours to make sure the seal was good before removal of the secondary valve began. As the valve was removed, it was determined that the rear pigging disc of the tool was four inches inside the spool flange, giving sufficient clearance for valve removal and replacement. Figure 3. The plugging tool is shown set in the spool, after the secondary valve has been removed. The red ring is the rear pigging disc. The small amount of clearance, which was the same on the front end, shows the precise positioning required. Once installed, the new valve was pressure-tested along with other plumbing on the launcher. The launcher was brought up to line pressure and the seals were retracted. The grips were released and the plug was pigged back into the trap. It was monitored as it entered the reduced bore of the pig trap. Once in the trap, the two isolation valves were closed, isolating the launcher. The launcher was depressurized, drained, purged with nitrogen, and flushed with water. The plug was removed from the trap, completing the job successfully. For more information about TDW Offshore Services http://www.tdwilliamson.com or call 1-832-448-7200 LineMaster™ 2005 Spring Schedule T.D. Williamson, Inc. continues to provide the most comprehensive hot tapping, plugging and pigging instruction available in compliance with Department of Transportation covered tasks, standards and requirements. Rigorous hands-on training and operator qualification LineMaster™ programs are TDW's commitment to the industry. LineMaster Training assists you with ensuring that your technicians are trained at the highest level available. In our state-of-the-art facilities and with our pressurized simulated pipeline, TDW's LineMaster Training program is an in-depth series of classes designed to fulfill DOT Pipeline Safety Operator Qualification rules. To meet DOT requirements, training programs must include classroom time, written exams and hands-on simulated conditions. TDW's LineMaster Training meets these requirements. TDW LineMaster Training is the best in the business. The company you've trusted with your piping maintenance needs for more than 80 years has the experience to train your technicians and operators effectively and efficiently. 2005 LineMaster Training Dates Locations Distribution Class May-June 30-2 Tulsa, OK - USA T-101 Class Sept 13 Tulsa, OK - USA Pigging Class Sept 14-15 Tulsa, OK - USA Transmission Class Sept 19-22 Tulsa, OK - USA Gas Distribution Class Sept 26-29 Tulsa, OK - USA New European Program call: 32-67-28-36-44 Nivelles, Belgium Class Information and Registration Form For more information, contact TDW at 918-447-5100 or toll-free at 888-839-6766. Or call your local TDW representative. New European LineMaster Training Program in Nivelles, Belgium contact Anne.Roberfroid@TDW.be or Call 32-67-28-36-44 Upcoming Trade Shows Don't forget to visit TDW's booth at upcoming trade shows. We are attending several in the next few months, including: Please check the entire 2005 show listing on the website. 2005 Trade Shows Dates Locations Lobos Services May 18-19 Corpus Christi, TX NPRA Refining May 24-27 New Orleans, LA AWWA - Am. Water Works June 12-16 San Francisco, CA Texas Gas June 26-29 Corpus Christi, TX You can submit other e-mail addresses by simply completing the fields below. Enter the email address you wish to add and select which version you wish to receive. email name Please choose the mailing list(s) you wish to join HTML Only Text Only To unsubscribe forward this email and note unsubscribe me, we will remove you. ® Registered trademarks of T.D.Williamson, Inc., in the United States and in foreign countries. TM Trademarks of T.D.Williamson, Inc., in the United States and in foreign countries.