Flowserve VTP Wet Pit - Manual (Page 43)

VERTICAL TURBINE PUMPS (VTPS) CENTRIFUGAL PUMPS ENGLISH 71569224 – 10-13
Page 43 of 76 flowserve.com
Typical safety guards 5.7.1.1
After initial startup, pre-lubrication of
the mechanical seal will usually not be required as
enough liquid will remain in the seal chamber for
subsequent
startup lubrication.
A screen guard is furnished with all pumps
having a two-piece headshaft or an adjustable
flanged coupling. This screen must be secured in
place prior to pump startup to prevent possible
contact with rotating parts. Typical arrangement is
shown in section 5.7.1.1.
Stuffing box adjustment 5.7.2
On the initial starting it is very important that the
packing not be tightened excessively. New packing
must be run in properly to prevent damage to the shaft
and shortening of the packing life.
The stuffing box must be allowed to leak for proper
operation. The proper amount of leakage can be
determined by checking the temperature of the
leakage, this should be cool or just lukewarm - NOT
HOT - usually 40 to 60 drops per minute will be
adequate.
When adjusting the packing gland, bring both nuts
down evenly and in small steps until the leakage is
reduced as required. The nuts should only be
tightened about one half turn at a time at 20 to 30
minute intervals to allow the packing to "run-in".
Under proper operation, a packing set will last a long
time. Occasionally a new ring of packing will need to
be added to keep the box full.
After adding two or three rings of packing, or when
proper adjustment cannot be achieved, the stuffing
box should be cleaned completely of all old packing
and re-packed.
Open shaft lubrication before startup 5.7.3
Open lineshaft bearings are lubricated by the
pumped fluid on short-coupled units less than 15 m
(50 ft) long and usually do not require pre- or post-
lubrication. All open lineshaft pumps where the static
water level is more than 15 m (50 ft) below the
discharge head should be adequately pre-lubricated
before startup. These units should have a non-
reverse ratchet on the driver to prevent backspin
when turning off pump. If there is no NRR, post-
lubrication is also necessary.
Enclosed shaft lubrication before start up 5.7.4
Enclosed lineshaft bearings are lubricated by an
extraneous liquid (usually oil or clean water
The oil reservoir must be kept filled with a good
quality of light turbine oil (about 30 cSt (mm
2 /sec) at
operating temperature) and adjusted to feed 3
drops/minute for every 30 m (100 ft) of column.
Injection systems are designed for each installation.
Injection pressure and quantity of lubricating liquid
will vary. Usually 0.45 to 0.90 m
3 /h (2 to 4 gpm) at
0.7 to 0.14 bar (10 to 20 psi) over maximum pump
discharge pressure of clean liquid is required.
For recommended oils for enclosed lineshaft bearing
lubrication under normal operating conditions, please
see tables 5.2.3.1 and 5.2.3.2. If none of the above
oils are available, oil with the following specifications
should be obtained. Turbine type oil with rust and
oxidation inhibitors added, viscosity 30 cSt (mm
2 /sec)
to 37 cSt (mm 2 /sec) at 40 C (100 F) with a minimum
viscosity index of 90.
In the case of product-lubricated
bearings, the source of product supply should be
checked against the order. There may be
requirements for an external clean supply, particular
supply pressure or the commencement of lubrication
supply before pump startup.
GUARDS
INSTALLED