HAYWARD GORDON LTD
Page
15
Rev:
1
HRF Series Mixers
Date 11/99
Section: RF
Liberally coat the shaft with lubricant such as molybdenum
disulphide paste for ease of sliding.
Back off all setscrews. Rock the hub to loosen and firmly slide the
hub away from pin applying an even load on opposite ears. The hub
may be tapped lightly through a wooden block to aid in this
movement. Heavier hammer blows may cause the bore to close in
and grab the shaft. When hub slides clear, remove hook key.
Stop the hub at the first sign of binding on the shaft. Forcing the hub
may induce galling in some materials. making removal even more
difficult. Back off from the binding spot, determine the cause and
correct it before continuing.
If needed, moderate heat of about 300-350°F (light straw temper
color) may be applied to the hub O.D. which will expand the bore for
removal over high spots. Heat concentrated on the thinner hub
section over the keyslot is most effective. Never allow the
temperature to rise above 450°F (dark straw to bluish temper color).
When using heat, handle the hub only with heat protecting gloves.
REPLACEMENT AND SECURING
Before replacing the hub onto the shaft, check the bore for burrs or
scratches. Coat the bore and shaft with molybdenum disulphide
paste. If the shaft is hung vertically, attach a safety tether securely
through one or more bolt holes in the hub and support from above.
Install the hub with the side up as indicated by matchmarks. It is
usually, although not necessarily, assembled chamferred side first.
Slide the hub to a point above its required position and replace the
hook key onto the shaft. Gently lower the hub onto the key until it
seats against the pin. Do not drop against the pin. Tighten setscrews
to torque listed below.
Install blades and tighten bolts to torques listed below.
Torque values shown are good for standard carbon and stainless
steel hex head bolts as well as nickel, monel, inconel, and Alloys
B,C, and 20 and are based on bolts lightly lubricated in the "as
received" condition. If lubricated with molybdenum disulphide paste
on threads and nut bearing face, bolt torques must be reduced to
75% of those tabulated.
All bolts should be tightened by turning nut side only.
All bolts should be re-tightened within 1 month after startup and at
each scheduled shut-down.
Impeller Blade Torques (A)
Dia
1/4
3/8
1/2
5/8
3/4
7/8
1
1-1/8 1-1/4 1-1/2
Torque ft.lb
4.8
17
43
85
130
200
270
400
500
730
GENERAL
Impellers from Hayward Gordon Mixers are normally shipped with
hubs mounted on the agitator shaft and with blades shipped loose.
Blades should be installed in strict accordance with matchmarks, if
any, and with bolts tightened to the torque listed below.
REPOSITIONING OR REMOVAL
Due to adjustment requirements or special installation procedures,
it may be necessary to relocate or even remove the impeller hub
from the shaft. Your Hayward Gordon impeller hub to shaft
clearance is optimized to provide maximum adjustability and
support with a minimum of fretting. therefore, even slight
distortions and scratches may cause the hub to "hang-up".
If more than one hub is to be removed, check the shaft and hub
for matchmarks. If none, mark clearly with a nonremovable
indicator, noting which side of the hub is to face up.
It is safest to remove or relocate hubs while the shaft is in the
horizontal position before installation. If they are to be moved while
the shaft is hung vertically, a safety rope must be tied securely
through one or more bolt holes and tethered from above to prevent
dropping or sudden movement.
Before proceeding, remove all scratches and burrs from the shaft
over which the hub must pass, as well as the hub bore. Do not
use tools which might contaminate special agitator materials, such
as metal files on stainless steel. Polish the shaft with emery cloth.
Set Screw Torques (B)
Dia
1/4
5/16
3/8
1/2
5/8
3/4
7/8
1
Torque ft.lb
5.8
11
19
42
82
140
330
460
