Graymills MVP Series Pump OMI - Manual (Page 3)

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ƒ High Pressure Filters for keeping fluid clean should
be used. Graymills can provide a filter to trap
particles, scale and contaminants to prevent costly
damage. Filter collects up to 20 cu. in. of material
(HPFB20) without pressure drop. Available in 14"
length single cartridge model (HPFB10) or 24"
length dual cartridge model (HPFB20). All models
are 304 stainless steel for use with water-soluble
and corrosive liquids. Reusable stainless steel
cartridges available in 10, 50, and 100 mesh.
OPERATION
CAUTION
Before starting, pump must be primed (free of air) and
discharge valves partially open.
ƒ Do not run pump dry; damage to mechanical seal
will result.
ƒ Use a Check valve on plumbing if pump is
mounted horizontally or if the potential to lose
prime can occur.
ƒ On-Off Cycling must be limited to under 100 times
per hour, because excessive starting cycles may
harm the windings of the motor.
ƒ Do not run against closed nozzles or damage to
pump and piping will result. Use Bypass as
described below.
ƒ Do not operate at or near zero flow.
ƒ If operating at or below 8 gpm or where valves may
be opened and closed periodically, you must use a
bypass. This kit (Bypass Kit C-39695),See Figure
1, installs in the side of the discharge head and
provides a fluid bypass when the pump is operated
against a closed discharge thus preventing
excessive heat build-up which will damage the
pump.
ƒ After stabilizing the system at normal operating
conditions, check the piping. If necessary, adjust
the pipe supports.
ƒ To ensure proper suction, fluid level should cover
first two impellers (5" from the suction end of the
pump). See Figure 1.
ƒ Pump may be mounted horizontally with optional
horizontal mounting bracket. However, care must
be taken to ensure that prime is not lost.
ƒ If pump is not generating enough pressure or flow,
see “TROUBLESHOOTING GUIDE”.
MAINTENANCE
WARNING
Failure to disconnect and lockout electrical power
before attempting any maintenance can cause shock,
burns or death.
ƒ Motors have permanently lubricated bearings. No
lubrication is possible or necessary.
ƒ Depending upon conditions and operating time, it
is important to perform regular inspections of the
pump. Items to inspect are as follows:
o Performance-Head, Pressure and
Flow
o Noise Level and Leakage
o Filter Cleanliness
ƒ The mechanical seal used is cooled and lubricated
using liquid within the pump. Separate lubrication
is unnecessary
ƒ To REMOVE pump from service, drain all fluid
from pump and piping.
ƒ To RETURN pump to service, replace all plugs and
piping using Teflon™ tape or equivalent on male
threads.
Disassembly
In most cases, the only maintenance necessary will be
replacement of the mechanical seal on the shaft. The
procedure below describes the process of
disassembling the pump’s stages to replace the seal.
ƒ Remove stay bolts on outside of pump column by
removing nuts on bottom end of bolts. Bolts can
then be unscrewed from motor bracket.
ƒ Remove suction cover from bottom of pump.
Remove O-Ring and Outer Chamber Sleeve. The
sleeve may need to be tapped and rotated to break
if free from the motor housing. There is an O-Ring
on both top and bottom of Outer Chamber Sleeve.
Inspect both after removal and replace if they show
signs of deterioration.
ƒ Remove nut and lock washer from shaft. The nut
has a left-hand thread to prevent loosening during
rotation of the pump. Each stage is a two-piece
construction of impeller and bowl/diffuser. The first
stage after the suction head will have a special
seal. During re-assembly make sure it occupies the
same position. The procedure should be the same
regardless of the number of stages in your pump.
ƒ Each stage is removed in the same manner as the
first. A screwdriver blade and application of mild
force might be needed to separate the sections.
DO NOT DEFORM OR BEND THE STAGES. Note
carefully the system of spacers. Each stage has a
spacer that prevents the impeller from contacting
the bowl/diffuser.
ƒ Once the stages have been removed, take the
circlip below the mechanical seal off the shaft.
Slide the seal off the shaft. Examine the seal for
damage or wear. If necessary, replace the seal.
ƒ If necessary to remove entire shaft from pump, it
will require the coupling guard, coupling and pin to
be removed. Remove the two fasteners that hold
the guard in place. Remove the four Allen-head