Tight Rubber Gasket

  • Didier Vassal, Vice President OEM and Maritime Services at Victaulic, compares the flanged and grooved pipe-joining methodologies and explains the advantages that grooved pipe joints provide over flanges. 
    Efficient piping systems are essential for the range of services needed on board a vessel including secondary systems such as bilge and ballast systems, sea and fresh water cooling, lube oil, fire protection and deck wash.
    For these systems, where piping class permits, an effective pipe-joining alternative to welding/flanging is the use of grooved mechanical joints which offer a range of technical, economic and practical benefits. These include enhanced performance; faster, simpler installation and maintenance and weight reduction on board. 

    Performance Issues
    In a flanged pipe joint, two mating flanges are bolted together and compress a gasket to create a seal.  As the bolts and nuts of a flanged joint absorb and compensate for system forces, over time the bolts and nuts can stretch and lose their original tightness due to pressure surges, system working pressure, vibration and thermal expansion and contraction.  When these bolts experience torque relaxation, the gasket will lose its compressive seal, which can result in varying degrees of leakage.
    Depending on the location and function of the piping system, leaks can be costly and hazardous, resulting in maintenance/repair downtime and exposure to risk.  Gasket replacement will be required when the joint is taken apart, as the gasket will bond to the flange faces during the course of time. When the joint is disassembled, the gasket will need to be scraped from both flange faces and these surfaces will need to be cleaned before the gasket is replaced, again increasing maintenance downtime. Due to the bolting forces along with system expansion and contraction, flange gaskets can also develop compression “set” over time, presenting another cause of leakage.
    The design of a grooved mechanical pipe joint overcomes these performance issues.  A groove is first formed in the pipe end and the piping connection is secured by a coupling which houses a resilient, pressure-responsive elastomer gasket. The coupling housing fully encloses the gasket, reinforcing the seal and securing it in position as the coupling engages and forms a positive interlock into the pipe groove.  The latest coupling technology enables pipes up to 24” (600mm) in diameter to be fully assembled with only two nuts and bolts in order to secure the self-restraining joint.  The mechanical joint creates a triple seal due to the design relationship between the pipe, gasket and housings, which is enhanced when the system is pressurized.

    Rigid and Flexible Couplings
    Available in both rigid and flexible forms, grooved mechanical pipe couplings are Class Society Type Approved, and may be used in lieu of welded/flanged methods in 30 systems, subject to installation criteria established by each certifying agency.
    Rigid couplings are used, for example, around areas such as manifolds and valves, where they offer easier access and replacement than flanges. By nature of their design, rigid couplings also provide axial and radial rigidity comparable to flanged or welded joints. 
    Flexible couplings have advantages in applications where relative movement between the pipe and supporting structure is anticipated, in addition to pipe movement resulting from thermal expansion or vibration. Expansion and contraction can stress the flange and piping, which can compromise the gasket over time. When this occurs, the joint is at risk of leaking. Grooved flexible couplings can accommodate pipe displacement in the form of axial movement or angular deflection.  For this reason they are ideal for installing long piping runs especially between blocks where high seas can cause flanges to loosen over time, resulting in leaks and the risk of pipe separation. Both rigid and flexible couplings also provide the benefit of noise and vibration attenuation, eliminating the need for specialised noise reduction components and perishable rubber bellows or similar items.
    Using a mechanical grooved piping system can speed up and simplify both installation and maintenance and improve the efficiency of onboard piping systems. 

    Ease of Installation
    On initial installation, bolt holes of a flange must be precisely aligned and then tightened to hold the joint. The bolt-hole index on equipment inlets and outlets must also line up perfectly with the flange on the piping to be connected to the unit. With only one of a number of fixed positions determined by the number of holes in a flange, a fitting or valve can only be rotated to match the bolt holes. Additionally, the opposite end of the flanged pipe must also line up with its mating flange, which further increases assembly difficulty and the risk of misalignment.
    Grooved piping systems do not have this problem and allow much more convenient installation with a full 360-degree rotation available for the pipe and mating components. There is no bolt-hole pattern to line up, and a coupling can be oriented at any position around the joint. The coupling can be rotated around the pipe to provide easy access to the bolts and simplify access to the equipment.
    In addition to eliminating misalignment during installation, a coupling’s 360-degree orientation capabilities, together with its smaller profile compared to a flange, make the installation of grooved systems ideal for confined spaces.
    Additionally, the installer can orient all of the assembly bolts on each joint in the same position to ease system inspection and maintenance.
    Flanges are roughly twice the outside diameter of the pipe they are attached to.  On average, grooved couplings are only half this size. The size advantage of the smaller design makes the grooved system ideal for jobs where space is limited, such as deck and wall penetrations - a fact recognised as far back as the 1930s when Victaulic couplings were originally used in U.K. shipyards.

    Speed of Assembly
    Because couplings have fewer bolts and no torque requirements up to 12” (300mm), grooved piping is much faster to install than flanging. Unlike flanges that must be welded to the pipe end, grooved valve assemblies do not require welding, which further cuts installation time and eliminates potential heat damage to the valve while also reducing safety risks by eliminating hot works.
    A comparison of a DIN 150 ballast line installed using Victaulic grooved products versus traditional joining methods showed a 66% reduction in total installation time required (150.47 man hours vs. 443.16 man hours).  The time needed to install 52 slip-on flanges and weld elbows and tees compared with 60 rigid couplings showed the largest time differences.
    Couplings require just two bolts up to 24” (600mm) pipe size. For comparison, at the higher size range a flange would require a minimum of 20 sets of nuts and bolts.
    In addition, flanges require time-consuming star pattern tightening with specialised wrenches to measure and ensure that correct torque specifications are achieved. Grooved pipe technology allows couplings to be assembled using  standard hand tools and the joint is properly installed once the mating bolt pads of the coupling housings meet metal-to-metal.  A simple visual inspection confirms correct assembly.  Flanges, on the other hand, do not provide visual confirmation: the only measure to ensure proper assembly is to fill and pressurise the system, check for leaks and retighten the joints as needed.

    Maintainability

    The same characteristics of grooved piping systems that accelerate installation—fewer bolts and no torque requirements — also make system maintenance or alteration a quick and simple task. To gain access to a pump or valve, for example, the two bolts of the coupling are loosened, and the housings and gasket are removed from the joint. In a flanged system, multiple bolts need to be removed. The same time-consuming bolt-tightening sequence required upon initial installation is also required upon reassembly of the flange.
    Because they do not require retightening, couplings eliminate much of the routine maintenance associated with flanges.  Unlike a flange that puts variable stress on the gasket, nuts and bolts, a coupling holds the gasket in precise compression from the outside of the pipe joint. Additionally, since coupling gaskets are not subjected to high compressive forces, they do not need to be replaced on a regular maintenance schedule, while flange gaskets need to be replaced when the system is disassembled for maintenance.
    To attenuate system noise and vibration, flanged systems require rubber bellows or braided flexible hoses.   These items can fail due to overextension and, with normal wear, need to be replaced every 10 years on average, incurring cost and system downtime.   Mechanical grooved pipe couplings, however, last the life of the system.  Their ability to accommodate system vibration reduces the risk of joint failure, without the need for speciality products that require periodic repair or replacement. The resilient elastomeric gasket contained within both flexible and rigid couplings is very durable and can handle significant operating pressures and cyclical loading. A system can be pressurized and depressurized repeatedly without fatiguing the elastomer gasket.

    Weight reduction

    Valve assemblies are typically constructed with flanged components. However, this joining method can add unnecessary weight to a piping system. A 6” (150mm) flanged valve assembly constructed with a lug butterfly valve, connected with weld-neck flanges and eight bolts and nuts on each side of the valve, weighs approximately 85 lbs.  A 6” (150mm) valve assembly that utilizes a grooved-end butterfly valve, grooved-end pipe and two rigid couplings to connect the components weighs approximately 35 lbs, representing a 58% weight reduction over the flanged assembly. A grooved valve assembly is therefore, an ideal alternative for the shipbuilding industry.  
    The above-mentioned comparison of a DIN 150 ballast line installed showed  a weight reduction of 30 percent (2,164 lbs vs. 3,115 lbs) when Victaulic grooved products were used instead of traditional joining methods.  The 52 slip-on flanges, bolt sets and gaskets, versus 60 rigid couplings accounted for major weight increases in the welded/flanged system.  
    Weight reductions by using grooved pipe couplings instead of flanges are achievable across a range of pipe sizes. The magnitude of the reduction depends on the pipe diameter and type of coupling used.  In tests where piping was connected using one Victaulic Style 77 coupling – the heaviest coupling in the range – compared with two light-weight PN10 slip-on flanges the total installed weight of the grooved assemblies was significantly lower.  Weight reductions were recorded as follows: 4” (100mm) – 67 percent; 12” (300mm) - 54 percent; 20” (500mm) – 60.5 percent. 
    With the lighter-weight flexible Style 75 or rigid Style 07 couplings and/or a heavier type of flange, weight reductions of 70% are easily achievable.  As an example, a 24” (600mm) flanged set for a TG2 system would weigh 507 lbs but a comparable assembly using Victaulic couplings would weigh only 88 lbs.  Shipyards that have used grooved couplings in preference to flanges on selected systems have recorded weight savings of 12 tons on offshore support vessels and 44 tons on cruise ships.
    The economic benefits of grooved technology to ship owners are clear: less weight means more cargo or passengers and less fuel consumption.  It makes the handling of piping systems on board easier as well.   

    Growing Trend

    Grooved piping systems can offer significant advantages over their flanged equivalents because of their speed of installation, maintainability and reduced weight.  These characteristics, coupled with additional benefits such as reliability, ease of alignment and lower safety risks, are leading owners, engineers and shipyards to choose grooved mechanical systems instead of flanges.
    This growing trend towards the use of grooved technology is supported by suppliers of equipment such as heat exchangers, box coolers and chillers, along with valve and compressor manufacturers, many of whom are now providing their products with grooved end connections.  The range of services where grooved pipe couplings may be used is steadily increasing. Building on successful applications in water systems, Victaulic is continuing its long history of innovation to develop fire-resistant gaskets and gain Type Approval for their use on maritime fuel services.  
     


    (As published in the April 2014 edition of Maritime Reporter & Engineering News - http://magazines.marinelink.com/Magazines/MaritimeReporter)

  • field installation and increased flexibility. A large selection of springs is available to handle a wide range of applications and pressure drops. Seat tightness is precision engineered to provide the same low leakage characteristics as single seated, unbalanced valve designs. The bonnet gasket is spiral

  • compressed asbestos gaskets. Positive seating is achieved with no metal-to-metal contact to cause friction and wear. The flow in the piping is sealed tight on both sides with an open space in between. "To inspect for leakage," explained Mr. Daniels, "you just take a quick glance into the open space

  • to both sides of the penetration, also cures to a rubber-like mass that withstands tremendous pressures, enabling it to achieve its gas and watertight ratings. Milcom selected the RISE system for several reasons. "First and foremost, I'm confident that RISE offers the best fire-stop protection

  • tanker and shoreside service. The valves handle high-pressure drops in either throttling or on/off service and will maintain flow characteristic and tight shut-off and start-up through cool-down and defrost. Other key features include: positive guiding, for accurate control and reduced trim wear

  • —Literature Available According to Clemco Industries, Burlingame, Calif., the Clemlite™ system of abrasive blast hoses, couplings and nozzles can heighten productivity by lightening operators' loads by as much as 62 percent, while offering improved safety and economy. Combining ultra-light weight wi

  • Victaulic, a manufacturer of mechanical pipe joining systems, introduces Vic-Press, an IACS-approved flame-free press system for joining small-diameter stainless steel pipe. With Type Approval certification from IACS member agency Germanischer Lloyd, Vic-Press offers a quick, simple, safe and reliable means

  • An energy-saving device that replaced steam traps on U.S. Navy ships won a $25,000 prize for the inventor, a civilian employee of the Navy, at a ceremony on the White House lawn. President Carter made the presentation to Lawrence L. Guzick for a constant flow Drain Orifice that is saving the U.S.

  • Schuyler Rubber Company, Inc., Woodinville, Wash., which custom designs and builds rubber fender products for the marine industry, has received the "Outstanding Achievement in Market Development Award" for the second consecutive year from the Washington Department of Ecology. The company designs

  • , access hatches allow easy repair or replacement of the propulsion units Vertically layered rubber fenders grip a steel hull like fingers, maintaining tight control yet easy disengagement with very little abrasion Two GM Detroit Diesel 16V-71N engines generate 1,070 hp, and are splayed 15 degrees off

  • Literature Offered All-rubber bearing staves designed and produced by American Metal Bearing Co. of Garden Grove, Calif., have been approved for use on U.S. Navy ships to replace other rubber and brass staves supporting propeller shafts. The approval was announced by Peter A. Pagan, vice president

  • Alex Lange, v i c e - p r e s i d e n t, and Louis P. Huyter, vice-president- sales of Alio International Rubber Ltd., Little Ferry, N.J., recently announced the appointment of Robert A. Salter as sales manager. Mr. Salter will be responsible for Alio International Rubber sales, reporting to Mr.

  • MR Dec-14#78 78  MARITIME REPORTER & ENGINEERING NEWS • DECEMBER)
    December 2014 - Maritime Reporter and Engineering News page: 78

    78 MARITIME REPORTER & ENGINEERING NEWS • DECEMBER 2014 MARINE FENDER & DOCK SYSTEMS RUBBER FENDERS ~ PANEL FENDERS ANCHORS ~ CHAIN ~ PELICAN HOOKS ABSORBENTS ~ DREDGE PIPE FLOATS UNDERWATER LIFT & SALVAGE BAGS D-SHAPE, WING & TUGBOAT FENDERS LIFE RAFTS ~ WINCHES ~ SHACKLES SHIP LAUNCHING MARINE

  • MN Dec-14#56   her ability to maneuver in tight  situations and hold steady)
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    has de- livered its powerful bow thruster systems to a Fire Boat for the City of San Francisco. Per speciÞ cations her ability to maneuver in tight situations and hold steady during Þ reÞ ghting operations will be fa- cilitated by WESMARÕs Model V2- 20 NS 100 HP stainless steel, dual prop,

  • MN Nov-14#30  reduction, but the weather-tight tonnage opening renders)
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    , ‘win-win.’ Integrating bolted tonnage openings into forward facing door frame bulkheads fulfi lls the need for tonnage reduction, but the weather-tight tonnage opening renders the water-tight door less waterproof. BOATBUILDINGCOLUMN Joe Hudspeth is Vice Presi- dent of Business Development at All

  • MN Nov-14#29  – 
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    November 2014 - Marine News page: 29

    reduction. Essex claims that for some vessels, “the use of tonnage openings – essentially a weather-tight means of ac- cess into a deckhouse – permits the ex- emption of space from gross tonnage. Depending on the interior layout, a properly positioned tonnage opening in a passenger vessel could

  • MR Nov-14#38 , by design, con-
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    November 2014 - Maritime Reporter and Engineering News page: 38

    par- allel, every time the drive revolves, the driven machine will speed up and slow down twice. Cardan shafts are, by design, con- structed for tight spaces that are not eas- ily accessible. Traditional laser align- ment procedures required that the cardan shaft be completely removed in order

  • MR Nov-14#10 , 
faced with historically tight markets, 
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    November 2014 - Maritime Reporter and Engineering News page: 10

    Slightly While conventional wisdom suggests that costs rise in step with time, it ap- pears that ship owners and manager, faced with historically tight markets, continue to defy conventional wisdom as total annual operating costs in the shipping industry fell by an average of 0.3% in 2013,

  • MT Oct-14#50  such as ß atness are very tight and tempera- tures are)
    October 2014 - Marine Technology Reporter page: 50

    . There are signiÞ cant differences between glass and crystalline materials such as sapphire and diamonds. When tolerances such as ß atness are very tight and tempera- tures are high, the choice of a crystalline material is superior to glass because it will maintain its shape at higher tempera-tures,

  • MT Oct-14#21  oil and gas    market  shale/tight oil and gas projects are)
    October 2014 - Marine Technology Reporter page: 21

     major energy companies have been cutting back on capital expenditures  a lot more supply has suddenly come into the oil and gas market  shale/tight oil and gas projects are competing for investment funds  constraints in the supply chain are creating delays and overruns  cost escalation

  • MT Oct-14#15  pull the  bow  ß ag tight on the Virginia-class)
    October 2014 - Marine Technology Reporter page: 15

    John Warner U.S. Navy photo courtesy of Huntington Ingalls Industries by John Whalen Shipbuilders at Newport News Shipbuilding pull the bow ß ag tight on the Virginia-class attack submarine Pre-Commissioning Unit (PCU) John Warner (SSN 785) in preparation for the boat?s Sept. 6 christening. The

  • MR Oct-14#3rd Cover  secured by running a lot of tight 
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    October 2014 - Maritime Reporter and Engineering News page: 3rd Cover

    scrabbling for savings wherever you can fi nd them. Profi t margins are what keep shipping lines afl oat, and that is best secured by running a lot of tight ships. And If you’re going to run a tight, compliant ship, it helps to monitor and track every turn of every piston, crank and wheel; every drop

  • MN Oct-14#40  entities moving into these tight-
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    October 2014 - Marine News page: 40

    then, this can probably be said of the global waterfront, as well. But the market is changing, driven by larger corporate entities moving into these tight- ly held markets, as well as a myriad of legislative and opera- tional conditions – namely the rapidly rising cost of fuel. ZF Marine – or more

  • MT Sep-14#56  to en-
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    September 2014 - Marine Technology Reporter page: 56

    indexes and radial rotation to deliver unlimited axial removal lengths. The weld crown and FBE removal steps are performed to en- sure a good seal and tight grip of the sleeve connectors. The CPT system is designed to carry out all severing and preparation work in a single deployment. Apart from tooling

  • MT Sep-14#8  one I’ve never seen, with a tight-knit 
community of professiona)
    September 2014 - Marine Technology Reporter page: 8

    . While there are many geographic regions throughout the world that claim to be a cluster, St. Johns is truly a cluster like one I’ve never seen, with a tight-knit community of professionals, companies, government and educational resources that is hard to match. Above and beyond all else I am anxious

  • MR May-15-77#50  
FROM STOCK. 
NEW WATERTIGHT DOORS 
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    May 15, 1977 - Maritime Reporter and Engineering News page: 50

    SALE NEW 7" RADIUS PANAMA CHOCKS (MEET PANAMA REGULATIONS) With extended legs for welding to deck. IMMEDIATE DELIVERY FROM STOCK. NEW WATERTIGHT DOORS 6-Dog right and left hand hinged steel doors — with frames. Built and tested to A.B.S. specifications. SIZE 26"x48" 26"x66" 26"x60"

  • MR May-15-77#49 , N.Y. 10004 
DOORS—Watertight—Joiner 
Overbeke-Kain)
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    , 112 W. Main St., Bay Shore, N.Y. 11706 DOCK BUILDERS GHH Sterkrade Ferrostaal Overseas Corp., 17 Battery Place, New York, N.Y. 10004 DOORS—Watertight—Joiner Overbeke-Kain Co., 20905 Aurora Rd., Cleveland, Ohio 44146 Walz & Krenzer Inc., 400 Trabold Road, Rochester, N.Y. 14624 ELECTRICAL EQUIPMENT

  • MR May-15-77#29 flushing spray 
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    flushing spray •water demister to an Airf ilco Inert Gas System r is its Scrubber exhaust gas inlet 3 stages impingement baffle trays Hot gases from the boiler uptakes pass into the venturi agelomeration section. Water is sprayed into the gas flow at a point upstream of the venturi and the

  • MR May-15-77#24 . CONTROL: Marine 
type watertight pushbutton — 
forward/reverse/)
    May 15, 1977 - Maritime Reporter and Engineering News page: 24

    enclosed —fan cooled—continuous duty— horiz. flange mounted — special shaft & oil seal fitted—440/3/60 -1760 RPM. CONTROL: Marine type watertight pushbutton — forward/reverse/stop—watertight starter box. DIMENSIONS: Barrel 10" diam.—top flange 1416" diam.—bottom flange 16V4" diam.—ht. of

  • MR May-15-77#7  
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    a modern application of the helical can pressure principle which sub- stitutes two to nine (depending LIMITED on flange diameter) quickly tight- ened cams for cumbersome nuts and studs. A permanently located "0" ring replaces the convention- al flange gasket and may be used again and

  • MR May-15-77#4 Dravo Corporation Names 
M.B. Meyer And J.J. Burke 
M.)
    May 15, 1977 - Maritime Reporter and Engineering News page: 4

    Dravo Corporation Names M.B. Meyer And J.J. Burke M. Bruce Meyer has been ap- pointed regional vice president, Far East, for Dravo International, with responsibility for spearhead- ing and coordinating Dravo Cor- poration's marketing activities in that area. J.J. Burke, formerly Dravo's

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    78 MARITIME REPORTER & ENGINEERING NEWS • SEPTEMBER 2014 Davit Sales Inc. Tel: 914-962-4544 • Fx: 914-962-5418 info@davitsalesinc.com WWW.DAVITSALESINC.COM SALES • SERVICE • MARINE ENGINEERING MARINE CRANES BOOM SKIMMERS PUMPS REFUELING SYSTEMS SINCE 1980 THE NAME TO TRUST FOR EQUIPMENT

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    September 2014 - Maritime Reporter and Engineering News page: 18

    cycles and more likely to stick with a borrower through the entire business cycle. The industry is now booming thanks to oil and gas, but this tight link to the oil and gas industries is a double-edged sword. A mid-size company borrower needs a lender that’s committed to the industry and

  • MR Jul-15-77#22 SNAME Pacific Northwest Section 
Holds Joint Meeting With)
    July 15, 1977 - Maritime Reporter and Engineering News page: 22

    SNAME Pacific Northwest Section Holds Joint Meeting With ASNE Principals shown at the joint meeting, left to right: Capt. James Nunneley, Shipyard Commander; Doug Hendrix, chairman, Pacific Northwest Section, SNAME; Charles Dick, speaker, and Capt. Lawrence Taylor, chairman, Puget Sound Section, ASNE.

  • MR Jul-15-77#6 Western Union Int)
    July 15, 1977 - Maritime Reporter and Engineering News page: 6

    Western Union Int'l To Market New MARISAT System A specially designed maritime satellite communications system is being marketed by Western Union International, Inc. (WUI), One WUI Plaza, New York, N.Y. 10004. The system, called MARISAT, was described by Roy K. Andres, WUI's vice

  • MN Sep-14#57   rigid, permanent, leak-tight joints.     www.victaulic)
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