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.


    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 Aug-14#96   steering provides a tight turning radius for precision)
    August 2014 - Maritime Reporter and Engineering News page: 96

    allows for the frame to ß ex under uneven terrain without causing structural damage or risking the safety of the load. Four-wheel steering provides a tight turning radius for precision handling of boats in limited spaces. ?And it requires no greasing,? Johnson says.?We deliver the unit delivered in pieces

  • MR Aug-14#60  panies making their way in a tight en-vironment are Meyer)
    August 2014 - Maritime Reporter and Engineering News page: 60

    income of all German shipyards includes a volume of more than $11.9B. Specialists NeededA good example of progressive com- panies making their way in a tight en-vironment are Meyer Werft in Papen- burg and its daughter company Neptun in Rostock-Warnemünde. In 2013 two cruise ships, one LNG-gas tanker out

  • MR Aug-14#40 40  Maritime Reporter & Engineering News ? AUGUST 2014 If)
    August 2014 - Maritime Reporter and Engineering News page: 40

    40 Maritime Reporter & Engineering News ? AUGUST 2014 If you operate a vessel, its machin-ery, without a doubt, will require alignment many times during the course if its life. When misalign- ment is present components will be worn, efÞ ciency will be lost, and, if left uncorrected, mechanical failures

  • MR Aug-14#36  expects the Texas  Wolfcamp tight oil play alone to draw)
    August 2014 - Maritime Reporter and Engineering News page: 36

    reach $140 billion in 2014.? The Þ gure is up 10% from 2013 and Rystad expects simi- lar growth in 2015. Wood Mackenzie expects the Texas Wolfcamp tight oil play alone to draw $12 billion in capital spending in 2014. Some of the growing capital expendi-tures on shale projects have undoubtedly migrated

  • MR Oct-77#15  puts a 25 ft. reach into the tight spots, 
retracts and)
    October 1977 - Maritime Reporter and Engineering News page: 15

    Mini Scissors This compact, versatile scissors model puts a 25 ft. reach into the tight spots, retracts and stores in minimum space. Also available in 21 ft. model. Scissors Manlift Gives you reach plus added lift capacity with work platform big enough for crew and equipment. Rent Your Reach A

  • MT Jul-14#45 MTRMTR  100 100BIOSwimmer from Boston Engineeringindustries.)
    July 2014 - Marine Technology Reporter page: 45

    MTRMTR 100 100BIOSwimmer from Boston Engineeringindustries. Globe Composite Solutions designs and manufac- tures advanced composite materials for components and ap- plications used in the industrial, medical, material handling, and defense industries. It specializes in custom non-metallic composite component

  • MT Jul-14#34  and is available in  a water tight pressure case conÞ  gura-tion)
    July 2014 - Marine Technology Reporter page: 34

    electronics will easily inte-grate into all small Unmanned Under- water Vehicles (UUV) platforms cur- rently on the market and is available in a water tight pressure case conÞ gura-tion. L-3 KleinÕs newly designed, rug- gedized transducers can be molded to meet the vehicleÕs space and conÞ gu-ration

  • MR Oct-15-77#60 .Y. 10013 
6-Dog right and)
    October 15, 1977 - Maritime Reporter and Engineering News page: 60

    Manufacturing Corp., 845 Larch Ave., Elmhurst, III. 60126 ZINC Smith & McCrorken, 153 Franklin St., New York, N.Y. 10013 FOR SALE NEW WATERTIGHT DOORS 6-Dog right and left hand hinged doors with frames. Constructed of 1/4" steel plate and meet Coast Guard regulations for above deck as

  • MR Oct-15-77#59  Shore, N.Y. 11706 
    October 15, 1977 - Maritime Reporter and Engineering News page: 59

    , Ferrostaal Overseas Corp., 17 Battery Place, New York, N.Y. 10004 DIVERS Undersea Systems, 112 W. Main St., Bay Shore, N.Y. 11706 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 Oct-15-77#49  bulkheads 
into watertight compartments. 
The "V")
    October 15, 1977 - Maritime Reporter and Engineering News page: 49

    knots) ; the inflatable, rubber sponson is buoyant and light. The boat's rigid bottom is divided in- ternally by longitudinal bulkheads into watertight compartments. The "V" hull flattens out to a third of the craft's length for good planing under load, fast beaching (up to 20 knots) in an

  • MR Oct-15-77#42 Stow Introduces New 
Remote Valve Control 
    October 15, 1977 - Maritime Reporter and Engineering News page: 42

    Stow Introduces New Remote Valve Control Flexible Shaft Stow Manufacturing Co. has just put on the market a new standard 3/8-inch-size remote valve control flexible shaft, which is ideal for manually remotely controlling all types of small valves in sizes up to those with 2-inch-diameter

  • MN Aug-14#70 MN
The Company:
Thordon Bearings Inc. designs and)
    August 2014 - Marine News page: 70

    MN 00 The Company: Thordon Bearings Inc. designs and manufactures a complete range of polymer bearing and shaft line products for the marine, clean power generation, pump, offshore and industrial markets. Thordon’s strong and recognizable global brand is known for high quality and superior

  • MR Nov-77#40 TURBO 
    November 1977 - Maritime Reporter and Engineering News page: 40

    TURBO GENERATOR SETS G.E. 1500 KW A.C. TURBO GENERATORS 1500 KW — 450/3/1200 RPM —o.8 P.F.—2450 ::: PSI—850°TT—8145 RPM—11- stage geared 8145/1200—type FN4 — 3y2" steam inlet. Unit will deliver full power at 440 lbs & 760°TT. OAL 16' 3-3/8"—OAW 6'6"—OAH 7'5%"-~wt. 36000 lbs. Almost equal

  • MR Nov-77#14  a dam and 
is approved as firetight, water-
tight and ratproof)
    November 1977 - Maritime Reporter and Engineering News page: 14

    , poured-type seal for the transit of electric cables through bulkheads and decks. It employs a simple technique for a dam and is approved as firetight, water- tight and ratproof. Although it is already installed in at least two ship classes, implementation is not as rapid as for splices. Pri- maril

  • MR Jul-14#35  to ensure that Prelude 
sits tight in savage seas.  First)
    July 2014 - Maritime Reporter and Engineering News page: 35

    of untethering the facility every time a bad wind blows and towing it to shore. Instead, a number of factors are supposed to ensure that Prelude sits tight in savage seas. First there is its sheer size and weight. But more important, Gilmour claims Prelude’s mooring system can stay on station even

  • MN Jul-14#64 64MN   July 2014ADVERTISER INDEX Page    Company)
    July 2014 - Marine News page: 64

    64MN July 2014ADVERTISER INDEX Page Company Website Phone#43 . . . . .Ahead Sanitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .www.aheadtank.com . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .(337) 237-5011 39 . . . .

  • MN Jul-14#51  paint processes, including tight con- trol of Dry Film)
    July 2014 - Marine News page: 51

    maxi- mum coating reliability ? a critical factor in preventing corrosion and extending the life of a vessel. Due to improved paint processes, including tight con- trol of Dry Film Thickness, paint transfer ef ciency of more than 75% could be achieved at BMP, resulting in a considerable reduction in paint

  • MN Jul-14#42 fuel economy. Since the late 1990s, the transition has)
    July 2014 - Marine News page: 42

    fuel economy. Since the late 1990s, the transition has mainly resulted in the move from 2 stroke to 4 stroke engines, linked to electronic fuel management systems. A notable exception is Evinrude that have stayed with 2 stroke engines and de- veloped their low emission technology E-TEC outboard range.

  • MR Nov-15-77#18 Plan To Convert Three 
Vessels At Estimated 
Cost Of $12.)
    November 15, 1977 - Maritime Reporter and Engineering News page: 18

    Plan To Convert Three Vessels At Estimated Cost Of $12.8 Million Bulk Food Carriers, Inc., 425 California Street, San Francisco, Calif., has applied for Title XI guarantees to aid in financing the conversion of the dry bulk car- riers S/S Tex and S/S Flor, and the oceangoing barge Burke F

  • MR Nov-15-77#14  are not required. 
Bubble-tight shut-off in both directions)
    November 15, 1977 - Maritime Reporter and Engineering News page: 14

    quick and easy. Seat replacement is simple, too, since no special tools are needed, and removal of the shaft and disc are not required. Bubble-tight shut-off in both directions, a seat that's self-compensating for wear, and excellent flow and throttling characteristics are some of the other features

  • MR Nov-15-77#6 Veliotis To Manage 
Electric Boat Div. 
General Dynamics)
    November 15, 1977 - Maritime Reporter and Engineering News page: 6

    Veliotis To Manage Electric Boat Div. General Dynamics Corporation has announced that P. Takis Ve- liotis has been named general manager of its Electric Boat Di- vision, Groton, Conn., the compa- ny's largest operating component. Gorden E. MacDonald, who has been serving as acting general

  • MR Dec-77#24 ICHCA Conference 
Set For Helsinki 
May 26-June 1)
    December 1977 - Maritime Reporter and Engineering News page: 24

    ICHCA Conference Set For Helsinki May 26-June 1, 1979 The XlVth Conference of IC- HCA (International Cargo Han- dling Co-ordination Association) will take place in Helsinki, Fin- land, from May 26 to June 1, 1979, under the theme "From Raw Material to Finished Prod- uct." R.P. Holubowicz

  • MR Dec-77#23 , modified with a new water-
tight bulkhead to accommodate)
    December 1977 - Maritime Reporter and Engineering News page: 23

    . Sphere Loading Upon arrival at Quincy, Her- cules is maneuvered into the out- board end of the shipyard's No. 6 basin, modified with a new water- tight bulkhead to accommodate the barge in an area 297 by 132 feet. The sphere is unfastened from its support structure and the basin is drained

  • MR Jan-78#3rd Cover BUYERS DIRECTORY (continued) 
PAINT—Coatings, Protective)
    January 1978 - Maritime Reporter and Engineering News page: 3rd Cover

    BUYERS DIRECTORY (continued) PAINT—Coatings, Protective Carboline Co., Marine Div., 350 Hanley Industrial Court, St. Louis, Mo. 63144 Clearkin Chemical Corporation, Schiller & Allen Sts., Philadelphia, Pa. 19134 Eureka Chemical Co., P.O. Box 2205, So. San Francisco, CA 94080 Farboil Company