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The Practical Pumping Handbook ...... ~;~::::: ......................................... :: .............. ::::::::::::::::::::::::::::::::::::::::::

12.9.2 Installing with a mechanical seal

1. Install the back cover with the seal chamber.
Check the back cover run-out by rotating the indicator through
.
360 ~ Total indicator reading should be within 0.005 inches.
Install the shaft sleeve until it is fully seated.
,
12.9.2.1 Installing the impeller with a mechanical seal
1. Using heavy work gloves to protect against the sharp edges of the
impeller install the impeller with the 'O' ring sea until the
impeller makes firm contact with the shaft.
2. Tighten the impeller onto the shaft in accordance with the pump
manufacturer's instructions.
3. Loosen the bolts and jacking screws on the bearing cap.

4. With feeler gauges, measure the gap between the rear of the
impeller and the face of the back cover.
5. Loosen off the bolts and jacking screws on the bearing cap until a
clearance behind the impeller of 0.030 inches is achieved.
In most ANSI pump designs, and in an as-new condition, this
approximates a front clearance of 0.015 inches from casing. This
final clearance must be established when the pump is fully
assembled, just prior to locking the mechanical seal down onto
the shaft.
6. Tighten the bearing cap bolts and the locking nuts on the jacldng
screws.
7. Check the impeller run-out, vane tip to vane tip. The run-out
should not exceed 0.005 inches.

8. Scribe a mark on the shaft at the position of the face of the seal
chamber. This will be the datum for the installation of the
mechanical seal.
Remove the impeller and seal chamber.
.
10. Obtain the Seal Installation Reference measurement from the seal
manufacturer's drawing. This is the distance from the face of the
stuffing box to the rear location of the mechanical seal. Inscribe
that point on the shaft.

11. Position the stationary face into the gland and slide them over the
shaft towards the bearings.

12. Install the mechanical seal on the shaft in accordance with the seal
manufacturer's instructions.

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