Page 584 - Subyek Teknik Mesin - Forsthoffers Best Practice Handbook for Rotating Machinery by William E Forsthoffer

The Post-Shipment Phase: Installation, Pre-Commissioning, Commissioning and Start-up Best Practices Be st Practice 1 0.11
Thrust bearings Auxiliary systems
Figures 10.11.9 and 10.11.10 show condition parameters and Condition monitoring parameters and their alarm limits are
their limits for anti-friction and hydrodynamic thrust bearings. defined in Figures 10.11.12 and 10.11.13 for lube and pump
flush systems.
Seals Figures 10.11.14, 10.11.15 and 10.11.16 present condition
monitoring parameters and limits for dynamic compressor per-
Figure 10.11.11 presents condition parameters and their limits
for a pump liquid mechanical seal. formance, liquid seals and seal oil systems.

Lube oil systems
Thrust bearing (anti-friction)
Parameters Limits
Parameter Limits
. 1 l i O s i v c o y t i s f f o s p e c 5 0 %
1. Bearing housing vibration (peak) 2. Lube oil water content below 200 ppm
a r l a i d 4 . 0 s / n i e c 1 ( 0 m m s / e ) c 3. Auxiliary oil pump operating yes/no operating
a l a i x 3 . 0 s / n i e c 1 ( m m s / e ) c 4. Bypass valve position (P.D.pumps) change > 20%
2. Bearing housing temperature 185 ° F(85°C) 5. Temperature control valve position Closed, supply
3. Lube oil viscosity off spec 50% temperature > 130 55°C)
4. Lube oil particle size 6. Filter P > 25 psid (170 kpag)
non metallic > 25 microns 7. Lube oil supply valve position change > 20%
m c i l l a t e a n y m a g n c i t e p e l c i t r a s h t i w s u m p
5. Lube oil water content below 200 ppm
Fig 10.11.12 Condition monitoring parameters and their alarm limits

Fig 10.11.9 Condition monitoring parameters and their alarm limits

Pump sealflush (single seal, flush from discharge)

Parameter Limits
Thrust bearing (hydrodynamic)
1. Flush line / 20°F ( / 10°C) of pump case
Parameter Limits temperature temperature
2. Seal chamber < 25 psi (175 kpa) above suction pressure
1. Axial displacement* > 15–20 mils (0.4–0.5 mm) pressure
2. Thrust pad temperature 220 ° F (105°C)
3. Lube oil supply temperature 140 ° F (60°C)
4. Lube oil drain temperature 190 ° F (90°C) Fig 10.11.13 Condition monitoring parameters and their alarm limits
5. Lube oil viscosity off spec 50%
6. Lube oil particle size > 25 microns
7. Lube oil water content below 200 ppm
*and thrust pad temperatures > 220°F (105°C)
1. Calibrated: pressure and temperature gauges and flow meter
2. Know gas analysis and calculate k, z, m.w
Fig 10.11.10 Condition monitoring parameters and their alarm limits 3. Perform as close to rated speed and flow as possible
4. Relationships:
k 1
LN
N 1
A. = B: EFFICIENCY poly = k
N n 1
LN
Pump liquid mechanical seal n
Parameter Limits
847.4 n
1. Stuffing box pressure < 25 psig (175 kpa) kgM = MW T1 n 1 Z avg p1 1
2. Stuffing box temperature Below boiling temperature for
process liquid
°
°
3. Flush line temperature + / 20 F (10 C) from pump case
temp T1
p1
4. Primary seal vent pressure > 10 psi (70 kpag)
(before orifice)
On tandem seal arrangements only 5. Compare to previous value, if decreasing trend exists greater
Typical limit – there are exceptions (Sundyne Pumps) than 10%,inspect at first opportunity
Fig 10.11.11 Condition monitoring parameters and their alarm limits Fig 10.11.14 Compressor performance condition monitoring

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