Pompetravaini TRSK 2002/1, Operating Manual, Page: 22 / 32

Operating manual liquid ring vacuum pumps TRVK - TRSK
22
13.2 - MECHANICAL SEALS
Mechanical seals can be with many types of materials, design and
installations (see fig. 21).
Their selection has been evaluated by POMPETRAVAINI at the time
of pump design, in function of the fluid and working conditions.
The seals are supplied with the proper flow of liquid for their lubrication,
through internal pump passages. Upon request, the pump can be
provided with seal lubrication coming from an outside source; the set-
up must be such that the seals are guaranteed the liquid quantity and
pressure as recommended by POMPETRAVAINI or by the seal
manufacturer.
Mechanical seals normally fitted in the vacuum pumps are to DIN
24960 standards.
Normally mechanical seals do not require maintenance until there is a
visible liquid loss (leakage).
Mechanical seals MUST NOT run dry! When seals are
operated without lubricant and/or flushing liquid their
faces and the elastomers may suffer damages beyond
repair. It is suggested to check the conditions of the seal
faces every approximately 4000 working hours.
ATT.: Take particular care of possible mechanical seals leaks of the pumped medium that, due to its
characteristics, might be dangerous for the environment.
N.B.: The data provided refers to the pumps of standard construction. For special constructions contact Pompetravaini.
13.3 - PACKED STUFFING BOXES
Pumps fitted with packed stuffing boxes require packing flushing either from an external source or directly from the
pumped media through pump internal passages.
This liquid is necessary to remove the friction heat generated between the shaft and the packing.
For the exact locations and dimensions of the flushing connections, see the pump dimension drawings.
In the pumps predisposed with external flushing to packing, the quantity of clean liquid for a correct flushing will have to
be determined using a flow regulation valve and reading on the pressure gauge (PI) a positive pressure of 0.2 to 0.4 bar
over that of the pump discharge pressure (see fig. 19 and 20).
If it is necessary to have flushing to the packing from the pump internal it is necessary to turn the seal housing by 180°,
allow the number 4 stamped on the casting to be at the upper position (see fig. 23 and 24).
This will guarantee the correct quantity of flushing liquid with a consistent flow thanks to the special channel provided
within the pump. This operation must be carried out by trained personnel, whit the
PUMP STOPPED .
Fig. 22
PREMITRECCIA
VITI DI
REGOLAZIONE
PROTEZIONE
BUSSOLA DI
CORPO
ANELLO DI
SBARRAMENTO
ANELLI
TRECCIA
CAMERA TENUTA
RETAINING ROTATING PART
SPRING
STATIONARY PART
GASKET (RUBBER BELLOWS)
ROTATING PART
GASKET (O-RING)
STATIONARY PART
RING
Fig. 21
ADJUSTING
BOLTS & NUTS
GLAND PACKING
SEAL HOUSING
CASING
SHAFT
SLEEVE
PACKING
RINGS
LANTERN RING