Flowserve Worthington WXB - Manual (Page 44)

WXB USER INSTRUCTIONS ENGLISH - 07/14
Page 44 of 51
the fluid establish the required margin between fluid
vapor pressure (at the seal chamber temperature)
and seal chamber pressure. In a Plan 23, the cooler
only removes seal face-generated heat plus heat
soak from the process.
Plan 76 is suitable only for fluids, where no
condensation of the inner seal leakage or from the
collection system will occur.
Leakage from the inner mechanical seal is restricted
from escape by the containment seal and goes out
the containment seal vent. An orifice in the outlet line
of the collector restricts flow such that high leakage of
the inner seal will cause a pressure increase and
trigger the PSH set at a gauge pressure of 0.7 bar
(10 psi). The block valve in the outlet serves to isolate
the system for maintenance. It may also be used to
test the inner seal by closing while the pump is in
operation and noting the time/pressure buildup
relationship in the collector. If specified, drain
connection on the piping harness may be used to
inject nitrogen or other gas for the purpose of testing
the containment seal as well as for checking for any
liquid buildup.
Disassembly of the seal cartridge
is only allowed by authorized personal. Contact
Flowserve for any service of the mechanical seal. We
recommend to have a spare cartridge seal on stock
for easy replacement.
8.1.3 Dual Mechanical Seal pressurized with
API–Plan 53c+61
Refer to mechanical seal drawing and
auxiliary piping drawing.
The pump is equipped with a dual mechanical seal in
face to back configuration, back to back configuration
or face to face configuration.
Try to turn the rotor by hand.If the
rotor cannot be turned, the pump must be
disassembled, refer to section 6.7.1 Dismantling
WXB.
The mechanical seal requires no adjustment
anymore. Check if the mounting plates are already
swung out.
Actions after start up:
Check all connections to the seal gland and the
mechanical seal itself against leakage. Check the
temperature of the seal gland. I slight increase of
temperature may be observed during the run in
period.
Plan 53 pressurized dual seal systems are used in
services where no leakage to atmosphere can be
tolerated. A Plan 53c system consists of dual
mechanical seals with a liquid barrier fluid between
them. The barrier fluid is contained in a piston type
accumulator. Inner seal leakage will be barrier fluid
leakage into the product. There will always be some
leakage (max.5 ml/hour).
The leakage rate is monitored by monitoring the seal
pot level. The product must be able to accommodate
a small amount of contamination from the barrier
fluid. The seal pot pressure must be maintained at
the proper level. If the seal pot pressure drops, the
system will begin to operate like a Plan 52, or
unpressurized dual seal, which does not offer the
same level of sealing integrity. Specifically, the inner
seal leakage direction will be reversed and the barrier
fluid will, over time, become contaminated with the
process fluid with the problems that result, including
possible seal failure.
Fill the seal system with a suitable
barrier buffer fluid (refer to lubrication table).
Open all necessary valves in the
cooling and auxiliary piping and check the flow.
API Plan 61 has tapped and plugged connections for
the purchaser´s use. Typically this plan is used when
the purchaser is to provide fluid (such as steam, gas, or
water) to an external sealing device.
Refer to the GA - drawing for the
required flushing fluid, pressure and flow.
Disassembly of the seal cartridge
is only allowed by authorized personal. Contact
Flowserve for any service of the mechanical seal. We
recommend to have a spare cartridge seal on stock
for easy replacement.
8.1.4 API Plan K
Refer to auxiliary piping drawing.
The pump is equipped with an API plan K, cooling to
bearing housing with parallel flow to seal heat
exchanger.
Open all the valves in the cooling line before start up
the pump.
Check cooling flow at the
installed flow indicator. If required adjust flowrate with
the flow control valve.
Refer to the GA - drawing for the
required cooling flow and pressure.