Flowserve MF User Manual

Page 35

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MF USER INSTRUCTIONS ENGLISH 71569191 12/04

Page 35 of 50

®

Check the shaft keyways for distortion. Excessive

thermal stresses or corrosion may loosen the

impeller on the shaft and damage the keyway.

Replace a shaft that is bent or distorted. If wear on

the shaft is slight, it may be possible to rebuild it by

metal spraying or plating and re-grinding. This repair

should be carried out by trained and competent

personnel.

After a shaft has been repaired, check it for possible

runout, maximum 0.051 mm (0.002 in.) T.I.R.

Recheck the runout after the bearing frame is

completely assembled.

When the sleeve has become worn appreciably, it

becomes difficult to adjust the packing to prevent

leakage and it should be replaced. Excessively

grooved and scored sleeves will tear new packing as

soon as it is inserted into the stuffing box.

Any sleeve grooved more than 3.0 mm (0.12 in.)

deep should immediately be replaced to avoid

damage to other components.

The shaft sleeve was mounted on the shaft

using Loctite RC/680 or equivalent and may require

heating to approximately 230

o

C (450

o

F) for removal.

6.1.7.1 Shaft sleeve removal

Uniformly heat the shaft sleeve to 230

o

C (450

o

F)

and remove the sleeve while the part is hot. If this

does not work, uniformly heat the sleeve to 260

o

C

(500

o

F) and douse with cold water. This will crack

the sleeve and allow mechanical removal of the

sleeve. If heating is not practicable, it will be

necessary to cut the sleeve off.

6.1.7.2 Mounting of shaft sleeve

Clean the shaft and shaft sleeve thoroughly and

remove any oil or grease from the mating surfaces

with a non-toxic solvent. Allow the solvent to dry and

apply Loctite type RC/680 or equivalent to the sleeve

inside diameter and shaft O.D. Install the sleeve and

sleeve key (for 3A and 4A frames this key is used for

impeller and sleeve) and apply adequate force to

assure metal to metal contact against the shaft

shoulder. This can be done by mounting the impeller

on the shaft and tightening the impeller nut. Remove

excess Loctite or equivalent adhesive from the

parting lines.

6.1.8 Maintenance of packing

Pumps equipped with mechanical seals may have

altered stuffing box dimensions. Refer to the seal

manufacturer's installation drawing for actual box

dimensions.

Use a good grade of non-asbestos packing with a

high temperature surface lubricant for packing the

stuffing box. Do not under any circumstances use

flax packing as rapid wear of the shaft sleeve may

result. The procedure for repacking the stuffing box

follows:

a) Remove the stuffing box gland.

b) Remove the old packing and seal cage halves

and clean the stuffing box.

c) Make sure the packing to be used is of the

correct type and size. Measure the stuffing box

to determine the proper length of packing.

Packing should be cut slightly shorter than

measured to prevent butting of the ends and

buckling.

d) Insert each ring of packing separately, pushing it

as far as possible into the stuffing box and

seating it firmly. Stagger the rings so that

successive joints are 90

o

to 180

o

angles apart.

e) After installing two packing rings, insert the seal

cage. It is important to make sure the seal cage

is located directly under the seal water

connection and that the installation of successive

rings does not displace it.

f) Continue adding more rings of packing. When

the required number of packing rings have been

added, install the gland and tighten the gland

nuts by hand, then back off the nuts until the

gland is loose. In tightening the gland, the nuts

must be brought up uniformly so that the gland is

not cocked and so that the packing is subjected

to a uniform pressure.

g) New packing has to be "run in". It is a good

practice to start the pump with the stuffing box

gland quite loose. After the pump has been

running for approximately 10 to 15 minutes,

gradually tighten the stuffing box gland nuts until

leakage is reduced to a steady supply or trickle.

Packing that is too tight in the box will cause

undue friction and create heat that will glaze the

packing and possibly score the shaft sleeve.

Packing must remain soft and pliable.

It may be impossible to add the last ring of

packing to the stuffing box and still insert the gland.

When this occasion arises, omit the last ring of

packing and adjust the gland. Continue to tighten the

gland as required, allowing for proper leakage, until

the packing has seated itself well enough to allow the

final ring to be inserted. Approximately 0.113 to

0.227 m

3

/h (0.5 to 1.0 gpm) at 0.34 to 0.69 bar (5 to

10 psi) above the maximum pump discharge

pressure is recommended for sealing water. When

grease sealing is used, a similar grease pressure

should be maintained.

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This manual is related to the following products:

MFC, MFV, MN