Unbalanced Mechanical Seal
Unbalanced Mechanical Seal
Described a seal design herein the sealing faces are exposed to the full hydraulic pressure at the sealing chamber without benebit of any predetermined counterblance measures. Its design simplicity, cost and ability to handle a moderate pressure range allows the unblanced seal to be seal extensively in pumping applications.
The unbalanced types of mechanical seals are used under drastic conditions where there are vibrations, misalignment of the shaft, and the problem of the cavitation of the fluid.
Crane Type 1 and 2 (unblanced ):
General purpose bellows type unblanced seal design similar to type 21. Flexible seal head moves freely under spring and hydraulic pressure, auto matically compensating for washer wear.To absorb both breakout and running torque, the seal is designed with a drive band and drive notches that eliminate overstressing of bellows. Slippage is eliminated, protecting the shaft and sleeve from wear and scoring.
Automatic adjustment compensates for abnormal shaft-end play, run-out, primary ring wear and equipment tolerances. Uniform spring pressure compensates for axial and radial shaft movement.
Crane Type 9 or 9T (Unbalanced):
Expressly designed to handle hight temperature and corrosive applications which would destory most synthetic rubber stocks.> The flexible sealing member is molded from Teflon, which is not affected by corrosive service. The rotating portion of the seal is driven through multi-springs and pinsby a collar locked to the shaft by means of setscrews.
Durametallic RO (Unbalanced):
Heavy duty multi-spring driven seal that incorporates "O" ring secondary seal along the shaft. Good for liquids not injuriousto BUN N, Neoprene, Viton or other synthetic rubbers.
General purpose seal that covers a wide variety of pumping applications and nearly all CPI appications. For use with liquids compatible with 316ss metal parts and Viton elastomers. standard face combinations are carbon vs. ceramic and Tungsten Carbide vs. carbon, E75-VV or EU5--VV respectively. Other face or material combinations are available.
Durametallic RO-TT (Unblanced):
Same seal as RO Except that Teflon "V" rings are used as secondary seals along the shaft. Especially suited to corrosive r high temperature liquids which wouldattack synthetic rubber.
Durametallic CRO (Unbalanced):
This seal incorporates synthetic "O" rings not only as the secondary seal along the shaft and for flexibly mounting the stationary inserts, but also to drive the rotatig assembly. It used quite often in the double arrangement where two seala are mounted.