Goulds Pumps 3910 11th ed. - IOM - Manual (Page 38)

WEAR RINGS (164, 202, 203, 230)
All units are equipped with casing (164), impeller (202 and
203) and seal chamber cover wear rings (230).
When clearances between the rings become excessive,
hydraulic performance decreases substantially.
1. Measure all wear ring diameters (Figs. 25, 26, 27).
2. Calculate diametral wear ring clearances. Minimum
diametral clearances should be as shown in Table 6.
3. Replace wear rings when diametral clearance exceeds
two times the minimum clearance as shown in Table 6
or when the hydraulic performance has decreased to
unacceptable levels. Refer to Renewal of Wear Parts
for replacement instructions for wear rings.
NOTE: For operating temperatures above 260° C
(500° F) and for materials with greater galling
tendencies (e.g. stainless steel), increase diametral
clearance dimensions by 0.13 mm (.005 in.).
38
3910-1
1th IOM 5/08
Table 5A
Model 3910 Bearing Fits & Tolerances (USA Units)
According to ISO 286 (ANSI/ABMA Standard 7)
Location Description
Group and Dimensions (inches)
SA SX MX, LA XLX
Radial
(Inboard)
Shaft O.D.
1.9690 2.3628 2.5597 3.5440
1.9686 2.3623 2.5592 3.5434
Interference
0.0001 0.0001 0.0001 0.0001
0.0010 0.0012 0.0012 0.0015
Bearing I.D.
1.9680 2.3616 2.5585 3.5425
1.9685 2.3622 2.5591 3.5433
Frame I.D.
3.5433 4.3307 4.7244 6.2992
3.5442 4.3316 4.7253 6.3002
Clearance
0.0000 0.0000 0.0000 0.0000
0.0015 0.0015 1.0015 0.0020
Bearing O.D.
3.5483 4.3307 4.7244 6.2992
3.5427 4.3301 4.7238 6.2982
Thrust
(Outboard)
Shaft O.D.
1.9691 2.3628 2.3628 3.3472
1.9686 2.3623 2.3623 3.3466
Interference
0.0001 0.0001 0.0001 0.0001
0.0010 0.0012 0.0012 0.0015
Bearing I.D.
1.9680 2.3616 2.3616 3.3457
1.9685 2.3622 2.3622 3.3465
Frame I.D.
4.3307 5.1181 5.1181 7.0866
4.3315 5.1191 5.1191 7.0876
Clearance
0.0000 0.0000 0.0000 0.0000
0.0015 0.0017 0.0017 0.0020
Bearing O.D.
4.3307 5.1181 5.1181 7.0866
4.3301 5.1174 5.1174 7.0856
Fig. 25