You are currently viewing the James Walker Global website.
You are currently viewing the James Walker Global website.
Our pressure‑responsive packing set for rods, glands and pistons. Popular with operators of older hydraulic plant.
Our Twinset packing set comprises an endless U-ring firmly supported by a header ring. The lips of the U-ring are slightly flared to provide an interference fit for initial sealing. When system pressure is applied, the sealing force is increased significantly by reaction within the tongue-shaped cavity of the U-ring.
Under slight axial compression, the header ring also spreads the U-ring lips slightly to improve low pressure sealing efficiency.
Although we recommend our more advanced designs for many traditional Twinset applications, this product remains a firm favourite with many operators of older hydraulic plant, and boasts a record of success stretching back over 50 years.
Twinset was developed for vertically reciprocating hydraulic shafts and rams. Current applications include the main rams of upstroking/gravity return presses and downstroking/prefilling type presses. It is also successful on press drawback rams, hydraulic piston heads, jacks and hoists, and hydraulic valves.
Note: This packing set should not be used under abrasive conditions or for heavy-duty applications (e.g., forging or extrusion presses), or on rams subjected to shock loads or side loads. In such cases, please contact us to recommend a suitable product.
U-ring
Header ring
Spring-loaded header ring
Standard materials are suitable for use with most mineral-based hydraulic fluids, lubricating oils and greases at temperatures up to +100°C (+212°F). They are also resistant to water and air.
The standards materials prove satisfactory for use with a number of fire-resistant fluids, including many of the phosphate ester type. Although swell will occur, most users find that this does not impair plant performance. Where fire-resistant fluids are used, it is essential to advise us of the type and designation.
Want to discuss your project, engineering or materials challenge expert to expert? Simply provide us with your contact details and a little information about the application you are working on, and one of our experts will contact you as soon as possible.
