Xylem Bell & Gossett e-80 Series, Инструкция по эксплуатации

Страница: 25 / 36

Balancing
It is recommended that impellers trimmed more than 5% in diameter be rebalanced per
ISO 1940 grade G6.3.
Angle cut guidelines
Model e-80 5x5x7B pump impellers must be angle cut at reduced diameters according to
the following information.
ØA ØB
C
Figure 11: 5x5x7B impeller trim — 0.125 in. (3.17 mm) increments
A B C
Hydraulic diameter, nominal, as
shown on selection curves
Diameter at impeller inlet side
shroud
Trim angle
From maximum diameter 7 in.
(177.8 mm) to 6.125 in. (155.6 mm)
Use diameter from selection curves 0 degrees, no angle
6, 5.875, 5.75, 5.625 in. (162.4 to
142.9 mm)
B = A plus 0.250 in. (6.35 mm) 8 degrees
5.5, 5.375, 5.25, 5.125, minimum 5
in. (139.7 to 127.0 mm)
B = A plus 0.375 in. (9.53 mm) 8 degrees
6.3 Pre-assembly inspections
Guidelines
Before you assemble the pump parts, make sure you follow these guidelines:
• Inspect the pump parts according to the information in these pre-assembly topics
before you reassemble your pump. Replace any part that does not meet the required
criteria.
• Make sure that the parts are clean. Clean the pump parts in solvent in order to remove
oil, grease, and dirt.
NOTICE:
Protect machined surfaces while you clean the parts. Failure to do so may result in
equipment damage.
6.3.1 Replacement guidelines
Impeller replacement
This table shows the criteria for replacing the impeller:
Impeller parts When to replace
Impeller vanes • When grooved deeper than 1/16 in. (1.6 mm), or
• When worn evenly more than 1/32 in. (0.8 mm)
6 Maintenance
Series e-80 INSTRUCTION MANUAL 23