Flowserve MSP - Manual (Page 30)

MSP USER INSTRUCTIONS ENGLISH - 07/14
Page 30 of 35
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
MSP.
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. It is usual that
at the seal faces a small leakage occurs after start
up, which decreases with the time of operation and
should stop after the seal is run in. Check the
temperature of the seal gland. I slight increase of
temperature may be observed during the run in
period. The mechanical seal is flushed by an API
Plan 32 and the temperature at the seal gland should
be max. 10 °C (18 °F) above the pumped liquid
temperature, unless otherwise specified by
mechanical seal supplier.
Plan 32 is used in services containing solids or
contaminants where a suitable cleaner or cooler
extern flush will improve the seal environment. It is
also used to reduce flashing or air intrusion (in
vacuum services) across the seal faces by providing
a flush that has a lower vapor pressure or that will
raise the seal chamber pressure to an acceptable
level. The external flush shall be continuous and
reliable even during non-standard situations such as
start-up or shutdown. The external flush shall also be
compatible with the process stream because it will
leak from the seal chamber into the process fluid.
In Plan 32, the flushing product is brought from an
external source to the seal. This plan is almost
always used in conjunction with a close-clearance
throat bushing as barrier to isolate the pumped
product from the seal chamber.
Refer to the GA - drawing for the
required flushing fluid, pressure and flow.
Plan 53 pressurized dual seal systems are used in
services where no leakage to atmosphere can be
tolerated. A Plan 53b system consists of dual
mechanical seals with a liquid barrier fluid between
them. The barrier fluid is contained in a seal pot and
is pressurized by using a bladder 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.
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.
7.2 Changing of mechanical seal
1) Completely drain the pump by using the drain
connection. By pumping explosive or toxic media,
flush the system with Nitrogen.
2) Secure the mechanical seal by putting the
mounting plates into the groove of the shaft
sleeve. Loose the clamping device, and
disconnect the seal piping.
Drain the seal system, if
applicable.
3) For disassembly refer to section 6.7.1,
Dismantling of pump.
4) For assembly refer to section 6.9.1, Assembly of
pump