Let’s talk about the importance of potable water. Safe to drink, even for infants, clean water supplies keep nations hydrated. The livestock on farms, the vegetables in fields, the taps in your home, they’re all categorized as potable water. This life-sustaining fluid is conditioned, often recycled and filtered, and it’s rarely squandered. Accordingly, it’s imperative that a water-sealing gasket functions as intended, with plenty of leak proofing strength.
Qualities to Look For In Potable Water Gaskets
Consider the nature of the liquid that’s flowing in a utility pipe. To be perfectly honest, the conditioned water isn’t wholly natural, not anymore. Additives have been introduced into the water supply. There’s chlorine in the line, with its disinfecting properties acting as a germ killer. In some communities, they also add fluoride to drinkable water supplies. The chemical additive protects the general public from tooth decay. For that latter additive, there’s some debate over whether the chemicals work, but that’s a matter for those who study such issues. Back with a potable water line, gaskets are installed that won’t weaken when a chlorine-mixed water supply flows.
Leach-Immune Water Fitting Sealants
So far, so good, the chosen gaskets in a potable water supply line can’t be damaged by abrasive water additives. If there are chloramines or ammonia, fluoride or some orthophosphate compound in a hydration line that’s meant for human consumption, then the applied rubber, fibre, or plastic gasketing medium cannot be sensitive to such moderately abrasive chemicals. Next, there’s another issue that can cause consumer concern. Briefly, if the sealing medium contains a chemical base that can be “leached” out of the rubber by a fast-flowing stream or one that’s hot, then this substance is clearly unworkable. To be clear, safe water supplies adhere to the AS/NZ4020 national standards, the NSF/ANSI 61 regulations, and Australia’s own WaterMark certification scheme. All of these rules are rigidly observed by pipe installers and gasket manufacturers.
Unstable elastomers with leach-sensitive plasticizers are clearly not utilizable in water lines or their fittings, not when those chemicals could prove hazardous to someone’s health. Having clarified that point, a few gasket labels are needed to close out this post. EPDM seals are chloramine resistant and hydrolytically stable. Durlon 7910, a branded gasket material, is another likely candidate. Nitriles and elastomers that satisfy the NSF/ANSI 61 standards also fall tidily into this category. Remember, people, livestock, crops, food preparation areas, and general potable water mains supplies all require leach-immune gaskets. To retain that key quality, they also must resist abrasive water supply additives, including chlorine and ammonia.
Anti-stick compounds coat gaskets so that maintenance techs can easily remove aging ring seals. If fibre or polymer reinforced gaskets didn’t include non-stick plating, how could a tech remove a used seal? Remember, when it was installed, torque-tensioned bolts crushed the material against two flange faces. Sure, that action does prevent pressurized fluids from creating a leakage pathway, but a cost is exacted after the fastener tightening work is done.
Anti-Stick Gasket Coatings Serve the Maintenance Sector
Upon watching someone tightening the bolts around a pair of flanges, it’s hard to believe this joint could be anything less than a permanent fitting. Masses of torque are pattern-tightened around the flanges. The gasket inserted between those faces is compressed until not one single drop or wisp of pressurized fluid can escape. Only, what if the pipe connection needs to be disassembled for some reason? Maybe a new generation of gaskets is taking over, or maybe the current seal is aging badly. If the flanges separate, after the bolts have been uncoupled, of course, then that obsolete material ring shouldn’t be impossible to remove. Even though it was compressed by unimaginable mechanical forces, an anti-stick coating should be in place so that an outmoded gasket can be removed without any kind of hassle whatsoever.
Employed as a Creep Relaxation Arbitrator
The case described in the above text is easy enough to picture. Surfaces and materials stick when they’re squeezed into a thinner shape for any length of time. How about the installation headaches encountered during a gasket’s installation, though? As the hard metals and tough fibres are crushed between two flange faces, they begin to spread. The squeezing mechanical force causes a gasket to thin and move outwards to the edge of the flanges. Usually, there’s nothing to worry about when this wholly expected spreading action occurs. However, static surfaces can “catch” or “seize up” when they spread over rough flange grains. When this happens, a gasket experiences strain. It distorts slightly and weakens. By coating gaskets in anti-stick coatings, they expand evenly under the crushing pressure. No creep distortion will take place when a gasket slips evenly under the compressive tightening pressure.
There are two primary reasons for adding a non-stick gasket coating. The finish performs as a creep relaxation compensation mechanism. As the flange fasteners tighten, a fitted gasket expands evenly. Essentially, that ring remains circularly shaped, even when it’s exposed to great compressive energies. Secondly, anti-stick finishes allow maintenance services to do their jobs without any gasket-sticking impediment getting in their way. The old gasket slips free. Otherwise, sticking stubbornly to the flanges, this work might just require the services of an abrasive tool, one that could possibly damage the flange faces.