Anti-keystone Technology
What is ANTI-KEYSTONE®Packing Technology?
Conventionally braided packings cannot simultaneously conform to both the shaft and the stuffing box bore and maintain parallel sides. When these packings are installed about a shaft or valve stem, the rings tend to form a trapezoidal cross section with the narrow side toward the outside. This happens because conventional packing has been braided in a square or rectangular cross section, as if it was intended to be installed in a straight groove, rather than around a shaft. Conventional packing needs to be forced into a square to be used. This creates uneven density, which results in excessive leakage and short packing and shaft sleeve life and sticking in valve stems.
ANTI-KEYSTONE® Packing Technology utilizes normal braiding equipment in a non-traditional way. The packing is braided asymmetrically in a "fan belt" shape, with the narrow side toward the inside. When installed about a shaft or stem, ANTI-KEYSTONE® Packing conforms naturally to form a square cross section about the shaft or stem. Thus ANTI-KEYSTONE® packing construction maintains parallelism of the two radial sides of the packing ring when installed.
ANTI-KEYSTONE® Packing Technology Reduces Shaft Sleeve Wear:
By maintaining essentially parallel radial sides of the packing ring, gland pressure is distributed across the whole of the packing and not just on the inner corners of the ring as occurs with conventional plait or interlocking braid. The resultant normal packing load on the shaft becomes more evenly distributed with ANTI-KEYSTONE® PACKING construction. This even load distribution greatly extends shaft sleeve and packing service life.
Other Advantages of ANTI-KEYSTONE® Packing Technology:
In addition to longer sleeve life, because the shaft sleeve stays smooth and straight far longer than with conventionally braided packings, the fluid film is thinner, resulting in lower leakage rates. For this same reason, there is lower power consumption and longer running time between adjustments. Our capitol patented technology eliminates the need for special devices to compensate for the "keystone effect."
The first benefit is due to the fact that ANTI-KEYSTONE® PACKING naturally squares itself around a shaft. The next three benefits cited accrue from the fact that the shaft sleeves stay relatively smooth and provided far longer service life than with conventionally braided packings. The fifth benefit, longer shaft sleeve service life, is the result of the more even load on the shaft sleeve by ANTI-KEYSTONE® PACKING. Experience shows that the net result of these five benefits is longer packing life.
In comparing results of these tests, ANTI-KEYSTONE® II PACKING provides up to twice the power savings and lower leak rates than our original ANTI-KEYSTONE® PACKING. Reporting the performance of ANTI-KEYSTONE® II PACKING, the CEO of our licensee, a major seal manufacturer said, "If this packing construction had been invented thirty years ago, we wouldn’t be making mechanical seals today".
Use in Reciprocating Equipment: As well as enhanced performance on rotating equipment such as pumps and agitators, experience shows ANTI-KEYSTONE® II PACKING also performs well in reciprocating services at low, medium, and high pressures.
NEBCO has incorporated this improvement into all of their styles of INDUSTRIAL Brand™ packing to be used for rotating and reciprocating equipment.
The Vibra-Damp™ SC and Chem-Stop™ AF Resilient core versions have also been converted.
Can you afford to NOT use the latest packing technology in your rotating and reciprocating equipment?
ANTI-KEYSTONE® II PACKING: The braided labyrinth seal. U.S. Patent 5,419,568 has issued in the United States and is pending in numerous countries throughout the world.