Vesconite Hilube has been the preferred choice for the pressure relief valves (PRVs) at the Hoover Dam. Originally designed in the 1930s, the PRV's divert water around the turbines when flow to the turbines needs to be stopped. Vesconite Hilube was selected to replace the existing cast iron parts, which had oxidised and seized, preventing the valve from functioning. Vesconite Hilube has proved to the ideal material for this application, due to its self-lubricating, hard-wearing, corrosion-free and low slip stick features.
Monthly Archives: January 2018
- January 30, 2018
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Blog.One of the decisions equipment designers need to make when installing O-ring seals in their applications is how much the O-ring will be squeezed by its mating hardware to create an effective seal.
What is O-ring squeeze
Squeeze is a ratio of the amount of deformation applied to the seal expressed as a percentage of the free-state cross-sectional thickness. Deforming the seal cross-section “energizes” the elastomer matrix much like compressing a spring; the inherent elasticity of the rubber material causes it to push back against the mating components. This contact force blocks the passage of liquids, gases and dry powders, preventing them from flowing between the rubber seal and the mating hardware.
The greater the squeeze, the more force is applied against the hardware and the tighter the seal. But that doesn’t necessarily mean that designers should always specify the most squeeze (assuming they knew what that level was or why it was “the most”). There are a number of factors to consider, which include:
- January 25, 2018
The environmentally sensitive hydro-power industry requires components that last longer in the absence of contaminating lubricants. These two factors alone make Vesconite Hilube the ideal bushing and bearing material in these demanding conditions. Water serves as a natural lubricant for Vesconite Hilube, which in turn, ensures a clean and grease-free operating environment. Unlike many traditional materials, Vesconite Hilube does not swell in water, nor does it distort or creep under load within wet hydro-power settings. Therefore not only does Vesconite last longer, so does it’s metal counterparts.
Hoover Dam pressure relief valves fitted with Vesconite Hilube
- January 23, 2018
O-Rings continue to be the most widely utilized sealing product. While the ‘Donut’ shaped profile has by and large been kept intact since their inception, continued elastomeric development has pushed o-ring temperature and chemical compatibility to limits unimaginable several decades ago.
Typically, O-Rings fail due to adverse effects of a number of factors, from improper installation and lubrication to incorrect size and design. The collection of videos below will help you minimize installation errors that may lead to failure (be sure to bookmark this page for future reference).
How To Install an O-Ring - Standard Male Gland
[embed]https://youtu.be/QcJBVQvTvhw[/embed]
- January 18, 2018
An Entire Solution in a Single Package
Freudenberg takes the customer out of the complex, tedious process of selection, adjustment and modification, providing integral sealing systems. The company has developed so-called ‘application cards’ that specific dedicated sealing systems for selected market segments and their applications. Here FST has gone beyond what is normal among its competitors. It doesn’t merely provide a fraction of all the components needed for hydraulic cylinders – it delivers all of them, from piston guides and seals, to primary and secondary rod seals, all the way to rod guides and wipers – and considers all their interactions in the process. As a result, a specialized knowledge of individual sealing elements is no longer needed.
- January 16, 2018
Gallagher Fluid Seals is a distributor of CIP Composites full product line. CIP Composites are laminated polymer materials made by impregnating textile with thermoset resins. The physical properties of CIP materials make them superior bearing materials. CIP Composites offer design engineers an attractive, cost effective alternative to the traditional material used for bushings, bearings, wear pads, and thrust washers. The following describes the physical characteristics and application factors to replacing bronze bearings with CIP Composites.
Physical Characteristics
Coefficient of Friction
CIP Composites have lower coefficients of friction than bronze in both static and dynamic situations. It is common to achieve 50% lower coefficients of friction when transitioning to composites. Bronze bearings pose a risk for metal to metal contact if grease is non-existent or not sufficient to support the shaft, and may develop high break-away torque requirements after prolonged periods of rest. CIP Composites are self-lubricated, minimizing the concerns with lubrication systems, specifically in high load, slow speed, or oscillating applications. CIP Composites eliminate noisy stick-slip problems, extend operating life and reduces wear, making for better operating efficiency.
Moisture Absorption
There can be concerns with moisture absorption for non-metallic materials. Moisture absorption can create swell and expansion of the bearing material and potentially premature failure. Some common plastics in use today have water absorption rates as high as 5-7%, which can lead to bore closure of the bearing and seizing on the shaft. CIP Composites have a negligible absorption of less than 0.1%, and effectively eliminate this concern when moving away from a metallic solution.
- January 11, 2018
Sealex® joint sealant, specially processed, 100% pure PTFE on a roll, provides soft, highly compressible gasketing for longer life and trouble-free sealing. Its form-in-place versatility also cuts maintenance and storage costs. The high compressibility of Sealex® enables it to effectively fill flange imperfections for a tight, leak-free seal. Under pressure, it provides a very wide, thin ribbon-like joint sealant. Unlike conventional PTFE which is prone to cold flow, Sealex® has good creep resistance and bolt torque retention properties.
Sealex® joint sealant does not support bacterial growth or cause product contamination and is FDA compliant. It has virtually no shelf-life concerns since PTFE is unaffected by normal environmental conditions.
It has excellent resistance properties to chemical attack. It is ideal for most chemical services at temperatures to 500°F (260°C) and pressure to 2,000 psi (138 bar). It is also suitable for cryogenic use to -321°F (-196°C).
- January 09, 2018
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Blog.
Precision O-rings are manufactured by vulcanization in a closed mold using compression or injection molding. This makes it possible to produce O-rings in relatively small manufacturing tolerances and with good surface quality according to ISO 3601-1 and ISO 3601-3. Due to defined vulcanization parameters, precision O-rings
- January 04, 2018
A chemical plant in northeastern Ohio could not keep their brine pumps sealed. The plant had been using titanium double mechanical seals on their ANSI pumps, but time and again the corrosive brine destroyed the $1,500 seals within 6 weeks of installation.
With 11 pumps on the brine system, the plant was spending over $100,000 a year on seals alone. As significant as that cost was, it paled in comparison to the lost operating time and potential health and safety issues.
The plant turned to Garlock for a solution and agreed to test the Hydra-Just® rotary seal. The results speak for themselves; the Garlock Hydra-Just® seal provided two to three times the service life as the titanium double mechanical seal and did so at a fraction of the cost. Additionally, it made for a safer workplace and substantially increased production uptime. As a matter of fact, the Hydra-Just®