Armstrong 4039 Series Manuel d'installation et d'utilisation - Page 4
Parcourez en ligne ou téléchargez le pdf Manuel d'installation et d'utilisation pour {nom_de_la_catégorie} Armstrong 4039 Series. Armstrong 4039 Series 8 pages. Belt driven pumps
Imprimer la pageCAUTION:
The discharge valve only is to be used to throttle pump flow, not the suction valve. Care must be taken in the suction
line layout and installation, as it is usually the major source of concern in centrifugal pump applications.
OPERATION
4.
STARTING PUMP
Ensure that the pump turns freely by hand, or with some mechanical help such as a strap and lever on larger
pumps. Ensure that all protective guarding is securely fixed in position.
The pump must be fully primed on start up. Fill the pump casing with liquid and rotate the shaft by hand to
remove any air trapped in the impeller.
"Bump" or energize the motor momentarily and check that the rotation corresponds with the directional arrow
on the pump casing.
To reverse rotation of a three-phase motor, interchange any two power leads.
Start the pump with the discharge valve closed and the suction valve open, then gradually open the discharge
valve when the motor is at operating speed. The discharge valve may be "cracked" or open slightly at start up
to help eliminate trapped air.
When stopping the pump: Close the discharge valve and de-energize the motor.
DO NOT run the pump against a closed discharge valve for an extended period of time. (A few minutes
maximum)
Star-Delta motor starters should be fitted with electronic/mechanical interlocks that have a timed period of no
more than 40 milliseconds when switching from star (Starting) to delta (Run) connection yet allow the motor to
reach full star (Starting) speed before switching to delta (Run).
Should the pump be noisy or vibrate on start-up a common reason is overstated system head. Check this by
calculating the pump operating head by deducting the suction pressure gauge value from the discharge gauge
reading. Convert the result into the units of the pump head as stated on the pump nameplate and compare the
values. Should the actual pump operating head be significantly less than the nameplate head value it is
typically permissible to throttle the discharge isolation valve until the actual operating head is equal to the
nameplate value. Any noise or vibration usually disappears. The system designer or operator should be made
aware of this soon as some adjustment may be required to the pump impeller diameter or drive settings, if
applicable, to make the pump suitable for the system as installed.
CAUTION:
Check the direction of rotation against the rotation arrow prior to operating the unit.
5.
PULLEY DRIVES
Ensure that the pulleys are clean and free from oil and grease. Make sure the pulleys are correctly aligned.
When placing a straight edge across the pulley faces it should touch across the whole of the machined faces
of the two pulleys for correct alignment. To check for correct tension measure the span length between the
two pulley centres. At the centre of the span apply a force at right angles to the belt to deflect one belt 16mm
per metre of centre distance. The forces required to deflect the belts are given below.
If the measured force falls within the values given
the drive tension should be satisfactory. A
measured force below the lower value indicates
under tensioning. If the force is higher than the
upper value the drive is over tensioned. However,
a new drive should be tensioned to the higher
value to allow for the normal drop in tension during
the running in period. After the drive has been
running for a few hours the belts will have seated
in the grooves and the drive tension should be
re-checked.
Force required to deflect belt
Best
16mm per metre of span
Selection
Small Pulley Dia. mm
67 - 95
SPZ
100 - 140
100 - 132
SPA
140 - 200
160 - 224
SPB
236 - 315
224 - 355
SPC
375 - 560
Page 4 of 8
(Kgf)
1.0 - 1.5
1.5 - 2.0
2.0 - 2.7
2.8 - 3.5
3.5 - 5.1
5.1 - 6.6
6.1 - 9.2
9.2 - 12.2