HAYWARD GORDON LTD Page 7
Rev: 1
HRF Series Mixers Date 11/99
Section: RF
Mechanical seal models can be supplied with double face type rotary seals, which must be
lubricated or with single dry running type which are self-lubricating.
Double mechanical seals require fluid lubrication either DEAD ENDED or CIRCULATED through
the seal chamber at a pressure 20 PSI above or 10% higher than the maximum pressure that will
be in the mixing tank. For longest seal life, light mineral oil is the best choice as a seal lubricant.
Many processes, however, cannot permit even the slightest oil contamination. In these instances,
we recommend that one of the process components or a compatible fluid be used. The chosen
lubricant MUST NOT attack the seal components or seal housing. If water is used as the lubricant,
we recommend that a corrosion inhibitor or a small amount of glycerin be added to the water to
improve its lubricity.
For maximum seal life, we recommend that the temperature of the seal lubricant be kept below
150°F for oil, 125°F for water and 100°F for solvents with a SG of less than 0.7. In most cases, the
absolute max temperature of the lubricant, to avoid seal failure, is 350°F.
The seal chamber pressure must always be greater than the pressure in the mixing vessel.
Therefore, DO NOT add pressure to the vessel until the seal chamber has been pressurized.
It is very important for satisfactory seal performance that no air is trapped in the seal housing -
ensure that all air has been bled from the system before starting up unit. The seal lubricator level
should be checked regularly and refilled as necessary. Good operating practice is to flush the
lubrication system every 5000 hours or every 12 months, which ever occurs first.
If the unit has been supplied with a single dry running seal, consult the enclosed manufacturer's
literature.
SHAFTS AND IMPELLERS
The extension shaft of your Hayward Gordon Mixer was straightened to within a few thousandths
of an inch prior to shipment from the factory. Care should be taken when handling the shaft to see
that it is not bent. After the unit is installed the shaft straightness should be checked. Total shaft
run-out at the end of the shaft should not exceed 0.003" per foot of shaft extension. If the shaft
run-out is greater than the above figure, the shaft can be straightened in the field. Place an
indicator on the side of the shaft where the maximum positive reading is obtained. Apply heat to
the shaft at a point 180° from the indicator and just below the first in-tank coupling or mounting
flange. As heat is applied - do not allow surface temperature to exceed 450°F (dark straw to
bluish color) - the shaft will grow toward the indicator. After the shaft has grown 0.030"-0.060",
remove heat and shaft will draw away from the indicator. The draw will be greater than the growth.
After each heating process, recheck the shaft straightness until within tolerance.
