23rd Wrld Gas Cnference, Amsterdam 2006 MUELLER CO. MAGIC BOX IN-SERVICE POLYETHYLENE INSERTION MACHINE B. KORTTE USA
ABSTRACT This paper details the features, functins and benefits f the Mueller C. MAGIC BOX Plyethylene Insertin Machine. The Mueller C. MAGIC BOX is the first self-cntained machine that perfrms wrk n plyethylene plastic gas mains frm a single excavatin site withut the need fr squeezing and building a temprary bypass line. This drastically reduces crew time, equipment needs, excavatin permits, and site restratin expenses. The MAGIC BOX System is based n the Mueller C. NO-BLO methd f n gas escaping int the atmsphere, r any disruptin f service. The Mueller C. MAGIC BOX System perates n 2", 3" and 4" diameter IPS plyethylene pipe, even with valves r repair clamps in place. Metric cnversin kits are available fr 63, 75, 90 & 110mm size pipe. The MB is installed arund the gas main and cuts ut the sectin f pipe quickly and cleanly with externally perated sltted blades. A replacement piece f pipe preladed in the MAGIC BOX machine can then be easily transferred int psitin and electrfused in place using mst universal prcessrs. Supprted electrfusin fitting manufacturers include Friatec, Inngaz, and Central Plastics. The Mueller C. MAGIC BOX can be used t install plyethylene ball valves, remve a bad jint (including cld jints r failed electrfusin cuplings), remve leaking service cnnectins, replace a damaged sectin f pipe (such as a scratch, guge, rck impingement, r temprary repair using a repair clamp). The fllwing areas will be utlined in regards t the Mueller C. MAGIC BOX. Prduct Backgrund Develpment Histry Prduct Applicatins Cnstructin f the MAGIC BOX Current Users Additinal Infrmatin
TABLE OF CONTENTS 1. Abstract 2. Mueller C. Magic Bx In-Service Plyethylene Insertin Machine Prduct Backgrund Develpment Histry Prduct Applicatins Current Prcedure The Magic Bx Slutin Cmmn Repair Prcedures Cnstructin f the Magic Bx Bdy Husings Blades Pressure Cntainment Seals Purge & Pressure Test Valves Grunding Terminal Over Pressure Indicatr Current Users Additinal Infrmatin 3. Appendix Insert Replacement Instructins
MUELLER CO. MAGIC BOX IN-SERVICE POLYETHYLENE INSERTION MACHINE Prduct Backgrund When the need t perfrm repairs n existing plyethylene natural gas mains arises, cmmn practice calls fr external by-passes, squeeze pints and multiple excavatins t be utilized. This methd can be bth cstly and time cnsuming. Due t the time and mnetary cnstraints f this methd, the innvative cncept fr the Mueller C. MAGIC BOX was brn. The MAGIC BOX is a single cmpact lightweight aluminium repair device that perfrms multiple repair prcedures n plyethylene pipe utilizing ne small excavatin. This is accmplished withut the need fr external by-passes. It currently can perfrm repairs n 2, 3, 4 and 63mm, 75mm, 90mm & 110mm plyethylene pipe with a maximum perating pressure f 100 psig. Develpment Histry The riginal prttype fr the MAGIC BOX was intrduced in the mid-t-late 1990 s by the Institute f Gas Technlgy (IGT) with funding prvided by Suthern Califrnia Gas Cmpany. The prject was adpted by Baltimre Gas and Electric Cmpany (BGE) with cntinued management by IGT. Mueller C. - Gas Prducts Divisin became the manufacture f chice fr the MAGIC BOX and hlds all patent rights t the MAGIC BOX and assciated material. The riginal MAGIC BOX prttype was designed t perfrm repairs n 2 plyethylene gas mains perating up t 100 psig. After multiple field evaluatins and industry fcus grup studies the cnclusin was made that the unit needed t perfrm wrk n a range f pipe sizes. The 2 MAGIC BOX prttype was redesigned t perfrm wrk n 2, 3 and 4 plyethylene pipe sizes. This versin was cmpleted in early 2004 with the first prductin units sld in May f 2004. There are currently 18 MAGIC BOX units being cmmercially perated tday by the fremst gas utilities in the U.S., with a number f ther gas cmpanies evaluating the technlgy fr future applicatins.
Prduct Applicatins Current Prcedure When repairing PE gas mains, current practice requires a cmplex set f peratins using multiple fittings and numerus pieces f equipment. (See figure 1) On average 20-30 steps are perfrmed using this type f repair peratin. These fittings are then left expsed t future third party damage by excavating equipment. Figure 1 With this methd a minimum f three excavatins are required t shutdwn and by-pass the gas arund the sectin t be replaced r repaired. This requires ne excavatin site fr the primary repair and tw smaller excavatins fr the squeeze and by-pass lcatins. The restratin csts alne assciated with repairing these excavatins can add up very quickly. If this temprary by-pass is nt cnstructed crrectly, custmers dwnstream f the repair culd ptentially be left withut service, causing additinal revenue lss. In additin t these cncerns, the pipe that is squeezed ff during the repair peratin needs t be identified as a squeeze pint fr maintenance purpses. This is usually accmplished with sme type f repair clamp r identifying tape. Standard perating prcedure des nt allw a previusly squeezed PE main t be squeezed again in the same lcatin fr fear f pipeline integrity issues. The MAGIC BOX Slutin The cre functin f the Mueller C. MAGIC BOX is t remve an existing sectin f PE gas main and replace it with a new sectin f pipe. This prcedure is accmplished under full cntinuus flw line pressure, up t 100 psig, withut the need fr external by-passes r squeeze pints. The entire MAGIC BOX peratin is perfrmed in Figure 2 apprximately 1 hur using a small excavatin site f 4 x 6. The MAGIC BOX can be used bth laterally and hrizntally which allws its use in jint trench peratins.
The MAGIC BOX peratin can be brken dwn int three basic steps. The phrase CUT, SLIDE, FUSE sums it up best. (See figure 3) 1. The MAGIC BOX CUTS a sectin f plyethylene pipe frm the existing PE main. 2. It then SLIDES int place a new pre-laded replacement piece f pipe r valve and fitting. 3. Finally it FUSES the preladed electrfusin fittings t permanently replace the valve r sectin f pipe. This all is perfrmed with n interruptin f gas service r any temprary by-passes r squeeze pints. Fr detailed peratin instructins please refer t the Operatin Manual fr the Mueller C. MAGIC BOX In-Service Plyethylene Replacement Machine (Frm #12358). CUT SLIDE FUSE Figure 3 Cmmn Repair Prcedures Listed belw are a few f the time saving repair prcedures that can be perfrmed with the MAGIC BOX. Remve an existing sectin f PE gas main that has been damaged. This damaged culd have ccurred frm a number f ways, such as third party damaged r rck impingement. In the United States, gas cmpanies are required t make repairs n damaged PE gas mains with mre than a 10% wall reductin. Install a PE ball valve int the gas line withut the need fr temprary by-passes r squeeze pints, t increase system cntrl and reduce system disruptins. Replace r remve an existing fitting frm a PE gas line. Sme examples are tees, ball valves, scket cuplings, bad electrfusin cuplings, etc. Remve a repair clamp that has been installed n a leaking PE gas main and replace it with a new sectin f pipe. The MAGIC BOX can accmmdate up t a 12 lng Mueller C. repair clamp. Perfrm repair peratins n lder generatin PE gas mains where squeezing is nt a practical ptin due t crack prpagatin.
Cnstructin f the MAGIC BOX Bdy Husings The tw halves f the MAGIC BOX are manufactured frm high strength, lightweight aircraft grade aluminium castings. Fur large lifting handles are built int bth the tp and bttm husings. These handles can be used t manually lift the unit int the excavatin site. Lifting straps can be used if needed. Bth the bttm & tp husings weigh apprximately 100 lbs and can easily be handled by tw peple. The MAGIC BOX will always be mved in sectins while the wrk is being perfrmed at the jb site. Built int the tp husing are three sight windws that allw the peratr t mnitr each step in the MAGIC BOX peratin. All sight windws are field replaceable in the event they becme scratched r damaged. The tw halves are secured by perimeter blts that are threaded int replaceable steel inserts cntained in the bttm husing. These inserts can be replaced in the field if damage ccurs t the threads. Please see Appendix A fr insert replacement instructins. Blades Figure 4 The sectin f pipe t be remved is cut with externally perated sltted steel blades. These blades are lwered thrugh the main using manually perated ratchets and sckets. Milled slts in the blades allw gas t cntinue flwing dwnstream while severing the sectin frm the main. Each blade cntains a hard stp which prvides the peratr with cnfirmatin f a cmpleted cut. The blades are als field replaceable if they becme damaged.
Pressure Cntainment Seals Tw perimeter -rings seal the halves f the MAGIC BOX. These -rings are hused in machined grves and prvide a psitive NO-BLO seal. T seal each end f the MAGIC BOX, gaskets are cmpressed arund the pipe by tw clamshell end glands that are blted t steel inserts hused in the MAGIC BOX ends. These seals prvide a NO-BLO peratin with every use. Purge & Pressure Test Valves Threaded int each end f the MAGIC BOX are ¼ turn ball valves. These valves are used t perfrm a leak check nce the MAGIC BOX is blted tgether and ready fr peratin. They are als used t perfrm purging peratins in the beginning and end f the MAGIC BOX prcedure. Grunding Terminal With each MAGIC BOX purchase a static electricity grunding rd is supplied. This grunding rd is attached t a terminal built int the bttm MAGIC BOX casting. Over Pressure Indicatr In the rare case f a pressure surge, an ver pressure indicatr is built int each MAGIC BOX unit. This valve autmatically pens in the event the MAGIC BOX encunters pressure ver the 100 psig maximum perating pressure. Current Users There are currently seven large natural gas distributin cmpanies in the United States using the Mueller C. MAGIC BOX System. They are listed belw. SOCAL Suthern Califrnia Gas & Electric, Ls Angeles, CA. PG&E Pacific Gas & Electric, San Francisc, CA. AGL Atlanta Gas & Light, Atlanta, GA. Questar Gas, Salt Lake City, UT. Keyspan, New Yrk, NY. PECO Philadelphia Energy Cmpany, Philadelphia, PA. Washingtn Gas, Washingtn, DC. Cnslidated Edisn, New Yrk, NY. A number f ther natural gas utilities are currently evaluating the MAGIC BOX In- Service Plyethylene Replacement Machine fr use in their PE distributin systems. Additinal Infrmatin T receive a MAGIC BOX infrmatin packet cntaining prduct vides and industry related articles please e-mail requests t Bryan Krtte at bkrtte@muellercmpany.cm. The MAGIC BOX vide can als be viewed at www.muellercmpany.cm. Click n Gas Divisin and a link t the MAGIC BOX vide will appear n the page.
Appendix A