Capped G-T Ring
6Pages

CAPPED GT RING SEALING SYSTEM The Greene, Tweed Capped G-TTM Ring is a double-acting, highpressure piston seal that combines the space-saving and non- extrusion features of more conventional compression-type seals with the low-friction, long-life characteristics of O-ring energized TFE cap-type seals. A positive seal that offers a high degree of sealability in both high and low pressure environments, the CGTTM Ring is designed to handle temperature extremes, a wide variety of fluid media and larger than normal clearances—yet requires a short axial length gland, and assembles and installs easily in the shop or in the field. Further, the CGT Ring is especially suited for long-stroke applications due to its low sliding friction and unique geometry which prevents roll and spiral. ELASTOMERIC SEAL PROBLEMS In designing, with many elastomeric compression-type seals, engineers have to deal with inherently higher friction as well as roll, spiral, nibble and extrusion failure problems which severely limit the performance envelope (Figures 1 and 2). The CGT Ring solves these problems, its geometry providing the high degree of stability necessary to overcome roll and spiral (especially useful in long-stroke applications) and its radially-energized backup rings preventing the “T” shaped elastomeric sealing element or off under motion or pressure (Figure 2). And, because the CGT Ring’s TFE cap is radially loaded in direct proportion to applied pressure levels, frictional losses and wear are reduced to an absolute minimum—while full sealability and Installed O-ring energized sealing element (no system pressure). prolonged seal life are maintained (Figure 7). Figure 3 © 2008, Greene, Tweed all rights reserved All trademarks are property of their respective owners. 06/08-GT DS-US-OF-058 TFE cap from wedging into the diametral clearance or pinching

PISTON DRIFT, PREMATURE FAILURE CLEARANCE LIMITS Unlike conventional cap-type seals, the CGT Ring virtually elimi- Wider clearances can be used when designing with the CGT nates piston drift. Piston drift is caused by low pressure leakage Ring. This allows for the use of wear rings which eliminate the past the cap. Because conventional caps (Figure 3) are not ade- possibility of piston and bore damage due to metal-to-metal quately energized at low pressures, leakage can occur—ultimately contact. Please consult Non-Metallic Wear Rings and Bearing resulting in piston drift. The CGT Ring’s cap...

TABLE 1 CGT RING DIMENSIONAL INFORMATION INCHES GT Dash Number Bore Diameter Gland Tolerance please refer to this drawing and gland dimensions listed in Table 1. SPACE REDUCTION The CGT Ring is ideal for use on components where axial space is at a premium. When replacing single or multiple lip seals, a substantial reduction in piston length can be achieved (even with the addition of wear rings). And, this reduction does not come at the expense of clearance limits or performance. Please refer to Table 1 for dimensional information. © 2008, Greene, Tweed all rights reserved All trademarks are...

TABLE 1 CGT RING DIMENSIONAL INFORMATION INCHES (CONTINUED) GT Dash Number Bore Nominal Seal CX Diameter (ØA) Gland Tolerance Diameter Gland Piston Bore Clearance (D) Length (G) Without With +0.010 Wear Ring Wear Ring -0.000 max. min./max conventional systems, the CGTTM Ring’s anti-extrusion rings serve as bore wipers, pre-cleaning the seal path and significantly reducing contamination-caused wear. 0.750 0.61/1.14 © 2008, Greene, Tweed all rights reserved All trademarks are property of their respective owners. 06/08-GT DS-US-OF-058 Energizer Compound No. (Table 1) GT Dash No. (Table 1)...

TABLE 1 CGT RING DIMENSIONAL INFORMATION METRIC GT Dash Number Bore Diameter Gland Tolerance The CGT Ring part number is designed to express the composition and size of the seal. Each sealing element material, energizer compound and anti-extrusion ring material is designated using numbers found in Table 1. Numbers for non-standard sizes will be assigned by Greene, Tweed Engineering. © 2008, Greene, Tweed all rights reserved All trademarks are property of their respective owners. 06/08-GT DS-US-OF-058 PART NUMBERING SYSTEM NOTE: Testing was done 30 Days @ 21ºC in 19 Chemicals With Wear Ring...

TABLE 1 CGT RING DIMENSIONAL INFORMATION METRIC (CONTINUED) GT Dash Number Bore Diameter Piston Bore Clearance (D) Without Wear Ring max. GLAND DETAIL With Wear Ring min./max © 2008, Greene, Tweed all rights reserved All trademarks are property of their respective owners. 06/08-GT DS-US-OF-058 *Zeros shown in these positions indicate standard size or materials. Any other number indicates non-standard, and is only assigned by GT Engineering. Contact Us Greene, Tweed Market Kulpsville, PA, USA Statements and recommendations in this publication are based on our experience and knowledge of...