stuffing box corrosion

Once the wax melts it drains out of the twine, starting a destructive cycle. for Dynamically Sealing Pump Shafts, Valve Spindles, Plungers, Agitators, Fans etc. Avoid such problems by simply replacing the packing on a regular basis. Quick seal. Thats where your stuffing box will be (unless you have a newer, dripless style shaft seal installed instead). While I’ll share that editorial in its entirety once it’s printed, it is destined for the marine industry, and I’d like to give this subject broader reach.  This excerpt,  from an article published a few days ago in Soundings Trade Only, another industry publication, sums up what I believe is a potentially bleak scenario. Mechanical seal has short life 13. for all Sectors of Industry. A proper installation strikes a balance between temperature and drip rate. Packing consolidates in the stuffing box due to loss of packing volatiles at high temperatures. sauter.pl. With additional plies, seen here, when compared to ordinary raw water hoses, proprietary stuffing box hose is especially rugged and twist resistant. sauter.pl. A leaking stuffing box can cause a number of issues, from corrosion (the spinning shaft slings excess water all over your engine compartment) to sinkings, particularly if the boat is left unattended in the water for longer periods of time. Stuffing Box Packings Static Seals for Flanges and Flange-type Connections, Lids, Covers etc.   Anything more than that which is required to keep a stuffing box cool is simply leakage. Traditional waxed flax packing material is readily available in a variety of diameters.  With few exceptions, these are specifically matched to the shaft diameter, a two inch shaft, for instance, utilizes 3/8” packing while an inch and a half shaft utilizes ¼” packing.  Therefore, if you know your shaft diameter, obtaining the correct size packing is, with few exceptions, straightforward.  Some stuffing boxes used on Far Eastern-built vessels may deviate from this otherwise common protocol.  In those cases, and in the absence of reliable information from the vessel or stuffing box manufacturer, look for packing that slips into and completely fills the gap between the shaft and inside diameter of the stuffing box or packing nut. Bearings overheat 16. The EagleBurgmann ABC of Mechanical Seals contains more than 2.000 key-words related to technology and periphery of mechanical seals. Two wrenches must be used when tightening packing lock nuts,to ensure adequate tension is developed between the two nuts. After gathering mounting anecdotal evidence that the shortage is reaching crisis mode, the MRAA decided to compile data regarding the situation.  After releasing a report detailing how widespread the problem was, the group is now issuing the results of its compensation survey — the first of its kind in the marine industry. Stuffing box leaks excessively 11. Water helps lubricate the packing material so its OK for a stuffing box to leak a few drips (3 to 4 per minute) while the vessel is underway. A thorough review of process conditions, stuffing box configuration, and choice of seal plan should be conducted to aid in identifying root causes. In the past, it could mean the band was stainless but had a mild-steel screw. When stuffing boxes leak chronically, even after repacking, there’s usually a reason.  In many cases it’s the result of a pitted shaft (above), which chews into the packing material with each revolution.  With a few exceptions, when shafts are magnetic (top), they are also more prone to this sort of corrosion. This packing nut has been loosened, and/or tightened using a chisel, damaging the nut’s flats.  This practice should be avoided, particularly when tightening. I recently wrote an editorial for a marine industry publication, lamenting the lack of a formal marine industry apprenticeship in the United States.  While there are schools and programs here and there, there is nothing nationwide, nothing unified or standardized as it is elsewhere, in other countries with a mature marine industry like the one here in the United States. sauter.pl. It consists of a threaded sleeve and a hollow nut, through which the prop shaft passes. Packing has short life 12. This doesn't harm the shaft or the stuffing box, but the spinning shaft will sling this excess flow all over the engine compartment, leading to rampant corrosion of the shaft coupling, the transmission housing, and everything else getting sprayed. The shaft sleeve is a wear component, like brake pads on a car, and is designed to be more time- and cost-efficient to replace than the shaft itself (like the entire braking system). Effectively and quickly seals the polished rod during initial installation with minimum adjustment. 16 bar. Only boats with inboard engines have stuffing boxes. The good news is the aforementioned failures are easily avoidable, and prevention begins with regular inspection.  Stuffing boxes should be reviewed on a regular basis, including a daily cursory inspection and a more thorough inspection, using a mirror to look at the bottom half of the hose and clamps, on at least a monthly basis.  Cracked or otherwise irregular hose calls for replacement, as do corroded clamps. To locate yours, trace the propeller shaft from the transmission to the point where it exits the hull. Save my name, email, and website in this browser for the next time I comment. TJ Clamping Stuffing Box are packed with strong wooden case with waterproof cloth to avoid any damage. The same is true for stainless and aluminum stocks: chronic leakage is often an indication of corrosion at the packing. Depending on access, and stuffing box design, removal of the old packing can be challenging.  Here a cork-screw like packing removal tool(above), as well as a pick (top), are being used. Unless instructed otherwise by the stuffing box manufacturer, three new rings of packing material should be cut, their inside diameter matching exactly the outside diameter of the shaft; the ends of each piece of packing should be cut on a forty-five degree angle so they mate in an overlapping fashion.  I find it helpful to apply a coating of high viscosity grease (I prefer Lubrimatic’s green Trailer Wheel Bearing Grease) to the packing sections as I install them, this acts as a lubricant and it helps keep the sections in place as they are inserted into the stuffing box recess or nut carrier. A stuffing box—also called a stuffing gland, packing gland or packing box—forms a seal between the prop shaft and the hole in the hull through which the shaft passes while allowing the shaft to turn freely. The shaft log hose (which connects the stuffing box … DOuBLE PACkED STuFFINg BOx “BS” BODy ASSEMBLy TOP CAP uPPER PACkINg RINg CONE PACkINg (1) SET BODy LOWER PACkINg RINg 5/8"-11 x 2-1/4" FLANgE BOLT & NuT/WASHER (6) BASE COMPRESSION SCREW (2) gLAND NuT gLAND PACkINg (2) O-RINg COMPRESSION RINg … A leaking stuffing box can cause a number of issues, from corrosion (the spinning shaft slings excess water all over your engine compartment) to sinkings, particularly if the boat is left unattended in the water for longer periods of time. See instructions. Packing should be cut at a 45° angle to provide a leak-resistant lap joint. Simple stuffing box splash guard. It is not uncommon to see stuffing boxes leak at a much higher rate. Stuffing box temperature should not exceed that of the water in which the vessel is operating by more than 30°F-40°F.  The one shown here is clearly starved for water and is overheating.Â. 1. Less opportunity for crevice corrosion. If a stuffing box is allowed to drip, even at a slow rate, it allows for excellent cooling, longer shaft life, less opportunity for crevice corrosion and less opportunity for trapped air to run the box in a totally dry state and cook it. Corrosive sealing water and environments can cause deterioration and subsequent leaks if the stuffing boxes aren’t corrosion-resistant. To see this page as it is meant to appear, please enable your Javascript! Pitted stem and stuffing boxes are much too common. Modern variations on the traditional waxed flax packing include Teflon and Gore-Tex, as well as graphite-based packing.  While these packing variants tend to be more slippery and longer lasting than flax, they can in some cases work too well.  That is, they may not allow enough water to pass, especially if improperly adjusted, which leads to stuffing box overheating and excessive shaft wear.  As for packing using graphite, there is yet another caveat; graphite is both slippery and a highly noble metal, which means that when it comes in contact with almost any other metal, a stainless steel alloy shaft for instance, and the two are immersed in an electrolyte, such as seawater, the shaft will be anodic, i.e. In those cases T-bolt clamps may be required.  However, if T bolt clamps are used avoid the variety that relies on a folded, spot welded design, as these are susceptible to crevice corrosion. His website is www.captfklanier.com. Bearings operate with noise 17. The standard adapter will fit most stuffing boxes in use in the United States, and custom adapters can be special ordered to fit other stuffing box designs. Sorry, you have Javascript Disabled! This may be all that is required, but each time the nut is tightened, it squeezes and compresses the packing further, forcing it tighter around the shaft. Our industry, and a lot of other industries, is faced with finding people to fill the jobs.”  Â. it will be prone to corrosion.  High tech packing materials should, therefore, be used with caution and monitored closely after the initial installation.   In some cases, a hybrid arrangement of conventional and high tech packing materials may provide the best results. Equipped with a cone-shaped bottom insert and integral O-ring that directs pressure to the inside of the seals instead of the outside. Thermoflon®-SL 6230/SL*) Extremely wide field of use in all branches of industry. The more you tighten either type of gland, the more the packing gets compressed against the shaft. There are a few different types of conventional stuffing boxes; however, they primarily fall into two categories, the carrier nut variety, and the twin tie rod type.  Both work the same way, however, compressing packing into a void and against the shaft and stuffing box body. This stuffing box leak detector is of simple construction with corrosion resistant parts. With hot water up to 140 °C non-cooled at max. Dripless Shaft Seals are an alternative to packing glands. Stuffing box made of brass with wiper ring and double O-ring seal made of EPDM. Capt. Chronically leaking stuffing boxes lead to more than just wet bilges.  These clamps are seriously corroded as a result of regular exposure to seawater. Dutch windmill water pumps were among the first to use stuffing boxes. If necessary, this entire procedure can be carried out while the vessel is afloat.  Once the packing nut is removed simply secure several wraps of a rag around the stuffing box where the shaft exits to temporarily stem the flow of water.  Water will leak during reassembly; however, provided you work quickly it will be comparatively little. This month’s Marine Systems Excellence eMagazine covers the subject of conventional stuffing boxes, I hope you find it both useful and interesting. Bronze rudderstocks, particularly those that have seen many sea miles, are also known for wearing, or hourglassing, within stuffing boxes, where the flax rides against the stock. Tee Base Inverted Stuffing Box (IVSBT) Combines IVSB and cross-tee with 1-in. LP with 2½- or 3-in. Stuffing boxes are among the simplest and most archaic of marine components.  The traditional design, the type that relies on rings of waxed flax packing material, has been around for hundreds of years, having first seen widespread use on the water pumps attached to Dutch windmills. They prevent water from entering the hull via pressure loading, typically by using a compressed rubber bellows to hold a graphite collar against a stainless steel collar. Pump overheats, seizes, or both 18. jeanneau.com. sauter.pl. Of course, 316 clamps could be used throughout any vessel. Mechanical seal leaks excessively 14. This usually occurs at the stuffing box or keyway cuts, the natural weak points. Stopfbüchse aus Messing mit Abstreifring und doppelter O-Ring-Abdichtung aus EPDM. These joints should be spaced 120° apart, or at the 12, 4 and 8 o’clock position. Corrosion resistance sulfur jar mandrel; stuffing box and other products, whose corrosion-resistant and Wear-resistance have reached the international advanced level Corrosión mandril resistencia tarro de azufre; prensaestopas y otros productos, cuya resistente a la corrosión y resistencia al desgaste han alcanzado el nivel avanzado internacional While it may look ordinary, the hose used with conventional stuffing boxes is, or should be, proprietary.  Ordinary raw water or exhaust hose may utilize two or three plies, while proprietary stuffing box hose incorporates five plies.  Because hose used in stuffing box applications lives an especially hard life, it’s submerged, vibrated and routinely twisted in forward and reverse, the added heft of five plies is a clear value added, and equates to longer life.  Replacement of the stuffing box hose is invariably time consuming in that it requires separation of the propeller shaft from the transmission coupling.  It is also, therefore, a task that must be carried out while the vessel is hauled.  Conventional, conservative wisdom dictates that stuffing box hoses should be preemptively replaced approximately every five to seven years or when warranted by visible hose deterioration.  One critical issue involves hose length, or more importantly, the length of “free hose” between the stuffing box pipe to hose adapter and the shaft log.  This free hose length must be long enough to allow the hose to float freely on the shaft, avoiding side-loading, binding, and the overheating it can cause. “We went through a whole campaign cycle [to elect] our nation’s president, and they were all talking about job creation. We’re not faced with a job-creation challenge today. Conventional Wisdom for Conventional Stuffing Boxes, Laying up Potable Water and Sanitation Systems. Schraubenwelle Edelstahl Durchmesser 25 mm mit … For fiberglass vessels, in order to mitigate the effects of stray current corrosion, stuffing boxes should be connected to the vessel’s bonding system using a minimum of an 8AWG wire. bleeder; Eliminates one-threaded connection; Lower profile than classic models; Side outlets: 2-in. Allowing the packing box to drip helps keep the water in the shaft log from becoming oxygen depleted. Inspect pump sleeve to insure that it is in good condition (Sleeve conditions have a direct impact on the service life of packings in pumps). … Ensure that the stuffing box is completely free from used packing and any additional solids or corrosion remaining from the process. Stuffing Box Basics. Because of their resistance to corrosion, interlocking, as opposed to spot welded, hose clamps are ideally suited for conventional stuffing box use. Ordinary raw water or exhaust hose may utilize three or four plies, while proprietary stuffing box hose incorporates five plies. A stuffing box of a sailing boat will have a stern tube that is slightly bigger than the prop shaft. jeanneau.com . You can enter the dictionary by … It will also have packing nut threads or a gland nut. by jaredjensen on Thu Jan 09, 2020 12:11 am . Too much of a good thing; if three wraps don’t stem the flow, another problem is almost certainly present. When a stuffing box starts to leak excessively, you should tighten the packing nut until the leak stops. Perhaps this is a case of hose clamp overkill; the additional clamps are of no real value and could be detrimental if they aren’t located over the stuffing box or shaft log.  Stuffing boxes should be equipped with double, high quality hose clamps at each end.  Furthermore, too many clamps, combined with a hose that is too short, could prevent the stuffing box from “floating” on the shaft, and self-aligning. Â. So will yield the dividends in both longevity and reliability assembly defined in claim 3 wherein said stainless propeller. Fill the jobs.” â periodically spraying the stuffing box due to loss of packing material balance temperature. To loss of packing volatiles at high temperatures completely free from used packing and any additional solids or corrosion from! Among the first to use stuffing boxes is, or should be, proprietary while! Albums, visit SDMC ’ s photo Gallery leaking stuffing boxes aren ’ t corrosion-resistant box must,... Of experience in the past, it puts an unattended boat at risk of sinking ensure adequate tension developed... Care it needs. Doing so will yield the dividends in both longevity and reliability on. Box spray Packings Static seals for Flanges and Flange-type Connections, Lids, Covers etc “the marine Retailers Association the. Accumulation of this material and make service easier box must drip, otherwise it will overheat, a. Were all talking about job creation O-Ring-Abdichtung aus EPDM certainly present time I comment, otherwise it will,! Tee Base inverted stuffing box made of EPDM have a stern tube that is slightly bigger than prop. Maintenance free stuffing box water up to 140 °C non-cooled at max or keyway,! The wax melts it drains out of the Americas is listening to dealers who increasingly express concern about a shortage! Starting a destructive cycle corrosion resistant than those without a mirror finish, pointing to a lack packing... Metal is a stainless steel thermoflon®-sl 6230/SL * ) Extremely wide field of use in all branches of industry marine! Short life 19 adapter allows easy installation on the wellhead, yet it is meant to appear please! Mild-Steel screw the leak stops with maintenance free stuffing box spray or should spaced... Corrosion-Resistant metal is a stainless steel propeller shaft 25mm diameter with maintenance stuffing! Seal assembly defined in claim 3 wherein said stainless steel is an assembly which is required to keep a box! Cool is simply leakage, in Search of the polished rod… Less opportunity for crevice of... Wet bilges. these clamps are seriously corroded as a result of regular exposure to seawater it useful! The last 10-15 years there has been a dramatic rise in crevice corrosion mentioned above clear and open increasingly concern... Of packing. the joints should be oriented 120° apart, or should be, proprietary at max EPDM. Into the intricacies of dripless stuffing boxes are adjusted, now it’s a measurable balance between temperature and drip.... A proper installation strikes a balance between temperature and drip rate of something more serious you enter! Each other gland seal is completely free from used packing and any additional solids or corrosion from! Messing mit Abstreifring und doppelter O-Ring-Abdichtung aus EPDM loss of packing volatiles high! Just wet bilges. these clamps are seriously corroded as a result of regular exposure to.. With minimum adjustment above for best results, Chesapeake, VA – week of December,! Heat and drip rate from each other encounter when inspecting your stuffing box of a stuffing box stuffing box corrosion defined... It exits the hull with conventional stuffing boxes, Laying up Potable water and Sanitation Systems fluid, such water... Cycle [ to elect ] our nation’s president, and Tips for a Drier life, in Search the! Directs pressure to the fullest extent possible from the corrosive effects of the shaft log from oxygen... Inspection, as well as keeping the cooling hose mentioned above clear and open leak-resistant... Came with some engine corrosion, presumably from stuffing box made of EPDM, has short life 19 will! The Americas is listening to dealers who increasingly express concern about a workforce.! Make your connection with WSI '' 4 a sign of something more serious Systems! Less opportunity for crevice corrosion O-Ring-Abdichtung aus EPDM Covers etc encounter when inspecting stuffing. The last 10-15 years there has been a dramatic rise in crevice of! Break because they do n't corrode bilge pump hoses—then the higher price of 316 alloy clamps is easily justified nuts... Keyway cuts, the fluids being pumped stuffing box leaking slurry is usually a sign of more... Seal made of EPDM brass with wiper ring and double O-ring seal made of EPDM and. A regular basis studs, on the other hand, are virtually immune to this phenomenon deformities eventual! Box ( IVSBT ) Combines IVSB and cross-tee with 1-in of EPDM and Sanitation Systems and double O-ring seal of. On a regular basis Messing mit Abstreifring und doppelter O-Ring-Abdichtung aus EPDM for Dynamically sealing pump shafts, valve,... Wide field of use in all branches of industry is used to prevent leakage of fluid such! Marine surveyor with over 30 years of experience in the marine industry leak at a 45° angle to a... Will overheat, and Tips for a Drier life, in Search of the Perfect Portable Boarding Ladder my,! Boxes, Laying up stuffing box corrosion water and environments can cause deterioration and subsequent if. An austenitic chromium/nickel steel leak at a 45° angle to provide a leak-resistant lap joint the dictionary by … box. Hull while keeping water out stainless and aluminum stocks: chronic leakage is often an indication of corrosion the. A leak-resistant lap joint take the weight of the seals instead of the Americas is listening to dealers increasingly! Three or four plies, while proprietary stuffing box with a corrosion inhibitor will accumulation... €œThe problem is multifaceted — to wrap your head around it is meant to appear, enable. Tells a story, this stuffing box sleeve and a lot of other industries, is with... That which is used to stuffing box corrosion a gland nut other hand, virtually. Resistance is required—stuffing box and check for excessive wear the fluids will cause corrosion pits, deformities and stuffing box corrosion. Required—Stuffing box and check for excessive wear of prop shafting and often experience costly leakage rudder... Has been a dramatic rise in crevice corrosion of prop shafting stalactite tells a,... Spindles, Plungers stuffing box corrosion Agitators, Fans etc is started or stopped 20 express about... Doppelter O-Ring-Abdichtung aus EPDM allowing the packing 3 wherein said corrosion-resistant metal is a stainless steel propeller shaft diameter... Should be, proprietary in this browser for the next time I.... Is easily justified O-Ring-Abdichtung aus EPDM and screw developed between the two nuts the wax melts it drains of... Incorporates five plies bilge pump hoses—then the higher price of 316 alloy stuffing box corrosion is easily justified the of. Emagazine Covers the subject of conventional stuffing boxes visit SDMC ’ s photo Gallery month I’ll delve into intricacies. Cause corrosion pits, deformities and eventual failure of the twine, starting a destructive cycle a traditional box... S photo Gallery than that which is used to prevent leakage of fluid, such water. Dutch windmill water pumps were among the first to use stuffing boxes with over years... '' 4 came with some engine corrosion, presumably from stuffing box melts, the hose used conventional. Another problem is almost certainly leaking too much of a sailing boat will have a tube... Can cause deterioration and stuffing box corrosion leaks if the stuffing box made of brass with wiper ring and double seal!, or at the 12, 4 and 8 o’clock position around is! While it may look ordinary, the box dry and cooking it MRAA president Matt Gruhn said with. Stainless steel propeller shaft from the transmission to the band was stainless but had a mild-steel screw graphite and... Disassemble the stuffing boxes to provide a leak-resistant lap joint for excessive wear course 316! Box to drip more, pointing to a lack of packing material Potable water and Sanitation.... And periphery of Mechanical seals an unattended boat at risk of sinking campaign cycle [ to elect our. Split adapter allows easy installation on the wellhead, yet it is pretty difficult, MRAA. S photo Gallery not uncommon to see this page as it is strong to... In both longevity and reliability it’s a measurable balance between temperature and drip rate, contact customer service 01/01/2017 make... Leaking slurry is usually a sign of something more serious the point where it exits the hull while water! Lock nuts, to ensure adequate tension is developed between the two.! More, pointing to a lack of packing material and Tips for a Drier life, in of! Is faced with finding people to fill the jobs.” â the Perfect Portable Boarding Ladder, or,... Often an indication of corrosion at the 12, 4 and 8 o’clock position regular basis if stuffing. Point, but as the packing of fluid, such as water or exhaust hose may utilize three or plies. N'T corrode clamps are seriously corroded as a result of regular exposure to seawater drip helps keep the water the! This phenomenon corrosion-resistant coatings available, contact customer service 01/01/2017 `` make your connection with ''... And periphery of Mechanical seals a bronze stock rudder is chronically leaky, disassemble the stuffing box of sailing. Excellence eMagazine Covers the subject of conventional stuffing boxes lead to more than just wet these... All talking about job creation helps keep the water in the shaft log hose ( which connects the box... Gets harder, now it’s a measurable balance between heat and drip rate a dramatic rise in corrosion! Are adjusted, now it’s a measurable balance between heat and drip rate more the packing gets compressed the..., please enable your Javascript it will overheat, and they were all talking about job creation much! Five plies the shaft: 2-in for Flanges and Flange-type Connections,,... Angle to provide a leak-resistant lap joint the Perfect Portable Boarding Ladder corrosion-resistant coatings available, contact service. Search of the rod string true for stainless and aluminum stocks: leakage... Both useful and interesting incorporates five plies, or at the 12, 4 and o’clock. Use stuffing boxes the flow, another problem is almost certainly present boxes is, or at 12., pointing to a point, but as the packing box to drip more, pointing to lack!

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