Flowserve MP1 Sier-Bath - Manual (Page 12)

MP1 USER INSTRUCTIONS ENGLISH 26999958 – 10-12
Page 12 of 48 flowserve.com
2.5 Recycling and end of product life
At the end of the service life of the product or its parts,
the relevant materials and parts should be recycled or
disposed of, using an environmentally acceptable
method and in accordance with local regulations. If the
product contains substances that are harmful to the
environment, these should be removed and disposed
of in accordance with current local regulations. This
also includes the liquids and/or gases that may be
used in the
“seal system” or other utilities.
Make sure that hazardous substances are
disposed of safely and that the correct personal
protective
equipment is used. The safety
specifications must be in accordance with the current
local regulations at all times.
3 PUMP DESCRIPTION
3.1 Configurations
Flowserve Twin Screw Pumps are single stage,
positive displacement pumps especially designed for
the petroleum industries in the transfer of oils and
other liquids of varying viscosities. The flow of liquid
through the pump is accomplished by the progressive
movement of sealed cavities formed by the
intermeshing of matched pumping screws (one right
hand, one left hand) rotating in the precision ground
bores of the pump body. To balance the hydraulic
thrust created by the pumping action, two sets of
meshed screws are used, moving the liquid from both
ends of the body to the discharge port located at the
center of the body.
The key assembly of the screw pump is the rotating
element. Each rotating element consists of a drive
shaft and a driven shaft running on parallel axes at a
fixed center distance. Each shaft holds bearings, one
timing gear and two opposing pumping screws plus the
assorted hardware (lock nuts, spacers) required for
mounting. With integral design, the pumping screws
and the shaft are an integral piece machined from a
single steel bar. Precise clearances are maintained
between meshing screws to limit the internal leakage
(slip) in the pump. The timing gears maintain these
clearances, prevent contact between the pumping
screws and turn the driven shaft. Heavy duty roller
bearings eliminate radial contact between the pumping
screws and the body bores and support the loading on
the shafts produced by the pumping action. Ball
bearings position the shafts axially and prevent contact
between the flanks (sides) of the meshing screws.
Generally lubrication of the bearings is provided by oil
contained in housings (sumps).
The rear timing gear configuration provides a rear pull-
out feature which permits the quick removal of the
entire rotating element without disturbing the pump
body or the drive. (Refer to Section 6.8 Disassembly).
The use of a spacer type coupling between the pump
and driver is necessary to apply this feature.
Shaft sealing is typically provided and installed by
factory. Mechanical seals require no adjustment prior
to or during pump operation.
All pumps are shop performance tested to ensure
mechanical reliability and compliance with the
specified conditions of service. They are carefully
inspected and prepared for shipment. All exterior
machined surfaces are coated with rust preventative
and all openings are provided with covers or plugs.
3.2 Name structure
The pump size will be engraved on the nameplate. The
following example explains how the pump name
identifies the construction features
MP1-275-355

MP indicates pump is for multiphase application

275 indicates screws OD in mm

355 indicates bore length in mm
3.3 Design of major parts
3.3.1 Pump casing
The pump casing is a casting with side suction and top
discharge connections, or both connections on top.
Refer to the Outline or General Arrangement drawings
for further details. It is a two pieces (Outer Casing and
Inner Casing or also typically named Liner) pressure
retaining casting assembly, with gasket connections
between the Outer and Inner Casing, as well as to the
seal housings and the suction and discharge flanges.
3.3.2 Pumping Rotors
The pumping rotors (screws) are single start and
mounted to a shaft in opposing configuration i.e. one
left and one right hand rotor to each shaft. The
intermeshing screws integral part of drive and driven
shafts create a positive displacement pumping action
inside the pump body.