Cornell 6NHTA - Run-Dry Seal Instructions and Parts Page

Supersedes 3200-625
June, 2018 Dec, 2020
Cornell Pump Company
Run-Dry Seal Instructions and Parts Page
Pumps equipped with Cornell’s patented Cycloseal
®
(patent # 5,489,187) system have an optional run-dry
feature. The run-dry feature employs an auxiliary gland and reservoir mounted to the backplate. The rotation
of the drive shaft circulates lubricant from the reservoir to the gland, then back to the reservoir. The lubricant
serves to cool the seal faces even when there is no liquid in the pump casing. A V-ring may be installed when
space allows.
THE RUN-DRY RESERVOIR LUBRICANT LEVEL SHOULD BE MAINTAINED WITHIN THE RANGE
SHOWN ON THE PLASTIC RESERVOIR OR TO THE TOP SIGHT GLASS OF THE METAL
RESERVOIR; however, lubricant will circulate as long as the lubricant level is above the bottom sight glass.
When filling the reservoir with lubricant, be sure the air has been purged out of the upper circulation hose to
prevent vapor locking.
Fluid changes recommended every 1000 hours or once a year, whichever comes first.
Lubricant can be added either during pump operation or while shutdown.
If water begins to accumulate in the reservoir, or the fluid level depletes rapidly, this may indicate mechanical
seal failure. Leakage of reservoir fluid from the gland would indicate a damaged or worn lip seal.
The optional run-dry feature is used for 2 different applications:
1. Backup Run-Dry Applications
With the backup run-dry feature, the pump can operate for a short period of time with no liquid in the pump
casing without causing damage to the mechanical seal. The run-dry option is not intended for extended periods
of operation without liquid in the pump casing, but rather as a safety feature to save the mechanical seal should
the pump unexpectedly lose prime or inadvertently be started without being primed.
Recommended reservoir lubricants:
The reservoir fluid should be Cornell 60/40 Propylene Glycol Run-Dry fluid with corrosion inhibitor
(p/n:N10263-415) or compatible fluid.
2. Extended Service Run-Dry Applications (Large Capacity Reservoir/Redi-Prime
®
Reservoir)
(NOTE: Internal pump tolerances have been modified for this application refers to BOM).
With the extended service run-dry feature, the pump can operate for several hours with no liquid in the pump
casing without causing damage to the mechanical seal.
Recommended reservoir lubricants:
The reservoir fluid should be Cornell 60/40 Propylene Glycol Run-Dry fluid with
corrosion inhibitor (p/n:N10263-415) or compatible fluid.