A.W. Chesterton 155 Installation Manual
MECHANICAL SEAL
INSTALLATION INSTRUCTIONS
15 5™
CARTRIDGE SINGLE SEAL
SEAL INSTALLATION
Preparation
Determine if the pump is in
good condition.
A. Check the shaft or sleeve.
1. Remove all burrs and sharp corners,
especially in areas where the O-ring
has to slide. Cover threads and
keyway slots with a thin tape to
prevent cutting the O-ring. The
distance from the face of the stuffing
box to the center of the O-ring
groove is .47" (12 mm). For shaft
sizes larger than 2.5" (60 mm),
this distance is .68" (17 mm).
2. The shaft finish should be no rougher
than 32 microinches (0,8 microns)
AA. It should feel smooth if you run
your fingernail along the shaft in the
axial direction.
3. Make sure the shaft or sleeve
diameter is within tolerance
(no more than +/- .002"
[0,05 mm] from nominal).
Example: 1.750" (50 mm) shaft
should not be larger than 1.752"
(50,05 mm) or smaller than 1.748"
(49,95 mm).
4. Use a dial indicator to measure the
shaft runout in the area where the
seal is to be installed. Readings
should not exceed .001" TIR per
inch (0,001 mm TIR per millimeter)
of shaft diameter.
5. Place the dial indicator on the end
of the shaft and alternately push and
pull the shaft in the axial direction to
measure end play. If the bearings are
in a good condition, end play should
not exceed .005" (0,13 mm) TIR.
6. Protect the sleeve O-ring by
lubricating the shaft with a clean
silicone based lubricant. A sufficient
quantity is provided with the seal.
B. Check the stuffing box face.
1. The stuffing box face must be
smooth enough for a gasket to
seal; maximum 125 microinches
(3,2 microns) AA.
2. Split case pumps will sometimes
cause a step (misalignment) to
occur on the stuffing box face.
This step must be machined flat.
3. Make sure the stuffing box is clean
and clear along its entire length.
4. If possible, attach the base of a
dial indicator to shaft and rotate
shaft and indicator slowly while
reading the runout of the stuffing box
face. Misalignment of the stuffing
box relative to the shaft should
not exceed .005" TIR per inch
(0,005 mm TIR per millimeter)
of shaft diameter.
Installation
1. Check the chemical listing to determine
if the FKM O-rings installed in this seal
are compatible with the fluid being
sealed. If it is necessary to change
the O-ring material, disassemble the
seal as shown in the instructions and
replace it with suitable O-rings. A spare
set of Ethylene Propylene O-rings is
supplied with the seal.
2. For 155 Small Seal (1" to 2.5"
[25 mm to 60 mm] shaft/sleeve):
The flat head socket screws (covered
with yellow dots) hold the lock ring
in place. These socket screws go
through the smaller holes on the
sleeve. Do not loosen the flat head
socket screws when positioning
the seal. The three cup point screws
next to the flat head socket screws
press on the sleeve. Their loading
configuration assists in centering the
sleeve on the shaft. The three cup
point screws further away from the
flat head socket screws go through
the larger holes on the sleeve. Make
sure these are engaged through the
sleeve but do not protrude into the
sleeve I.D. bore.
For 155 Large Seal (larger than
2.5" [60 mm] shaft/sleeve): The
flat head socket screws (covered
with yellow dots) hold the lock ring
in place. These socket screws go
through the smaller holes on the
sleeve. Do not loosen the flat head
socket screws when positioning
the seal. The three hybrid dog/cup
point screws press on the sleeve.
Their loading configuration assists
in centering the sleeve on the shaft.
The six cup point screws go through
the larger holes on the sleeve. Make
sure these are engaged through the
sleeve but do not protrude into
the sleeve I.D. bore.
3. CAUTION: If the 155 seal is
operating at a stuffing box
pressure of over 300 psig (20 Bar)
or if the shaft is case hardened,
replace the three 316 stainless
steel set screws that go through
the larger holes on the sleeve
with the hardened steel set
screws supplied with the seal.
SEAL INSTALLATION
4. For 155 Small Seal (1" to 2.5"
[25 mm to 60 mm] shaft/sleeve):
Attaching the 478 or any other
gland or re-attaching the tabs.
A. When using the 478 or any other
gland instead of the tabs, remove
the tabs by removing the tab
retaining snap ring and pressing the
tabs towards the center of the hub
gland and then sliding them out.
Slide the 478 or other gland over
the hub gland until it bottoms out.
B. If the tabs need to be re-attached:
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up, on a flat surface.
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a tab, apply a small amount of
silicone grease to the bottom
of the spring. This will help the
spring stay in the hole. To install
a tab, compress the tab spring
by pressing the tab against the
hub gland surface and slide the
tab till it bottoms out on the hub
gland. Place the desired number
of tabs, in pairs, at the required
orientation. As a minimum two
pairs of tabs must be used.
When the 155 seal is operating
at a stuffing box pressure of
over 300 psig (20 Bar), four
pairs of tabs must be used.
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gland groove. The snap ring
will prevent the tabs from falling
off, but can be removed at
any time without affecting the
performance of the seal. Make
sure that the gap between the
ends of the snap ring is aligned
with the slot in the hub gland
for the centering strap.
5. Slide the seal onto the shaft,
by pushing on the lock ring.
6. Reassemble the pump and make
necessary shaft alignments and
impeller adjustments.
7. Orientate the flush connection to the
location required. The port is plugged
prior to shipping. Removal of the
plug will require 25 lbs.-ft. (33,9 Nm)
of torque.
8. Piping connections should not
be made prior to tightening the
gland bolts.
9. Tighten the gland nuts evenly.
IMPORTANT: The gland nuts must
be tightened before tightening
set screws onto the shaft.
10. The seal has been designed to
promote self-centering of the sleeve
on the shaft. Following the set screw
tightening procedure outlined
below will lead to the maximum
self-centering possible.
For 155 Small Seal (1" to 2.5"
[25 mm to 60 mm] shaft/sleeve):
Tighten the three cup point set
screws, that are closer to the flat
head screws, evenly. If necessary,
tighten the three flat head socket
screws with the hex keys provided.
Then tighten the three cup point set
screws, that are further away from
the flat head screws, evenly. After
these three cup point screws have
been tightened with the hex key,
tighten them again with a torque
wrench to 50-60 lbs.-in. (5,7-6,
8 Nm). Pull out the centering strap,
and save the strap. If the strap is
lost after seal installation, a standard
wire wrap, .054" thick by .187" wide
(1,37 mm thick by 4,75 mm) can
be used.
For 155 Large Seal (larger than 2.5"
[60 mm] shaft/sleeve): Tighten the
three hybrid dog/cup point set screws
evenly. If necessary, tighten the three
flat head socket screws with the hex
keys provided. Then tighten the six
cup point set screws evenly. After
these three cup point screws have
been tightened with the hex key,
tighten them again with a torque
wrench to 50-60 lbs.-in. (5,7-6,8 Nm).
Pull out the centering strap, and save
the strap. If the strap is lost after seal
installation, a standard wire wrap,
.068" thick by .300" wide (1,73 mm
thick by 7,62 mm) can be used.
11. IMPORTANT: It is important to
make sure that the gland is properly
centered over the sleeve. To do this,
turn the shaft by hand to make sure
the seal turns freely. If you hear metal
to metal contact within the seal, it
was improperly centered.
For 155 Seal:
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the slot in the hub gland.
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UÊ ÃiÊÌiÊÃiÌÊÃVÀiÜðÊ
(Do not loosen the flat head
socket screws as this will allow
the lock ring to come off).
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surrounds the seal sleeve. It will
pilot between the hub gland, seal
sleeve and lock ring.
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UÊ ,iÌ}ÌiÊÌiÊÃiÌÊÃVÀiÜð
UÊ ,iÛiÊÌiÊViÌiÀ}ÊÃÌÀ>«°
If metal to metal contact still exists
check the centering of the stuffing box.
Take all necessary precautions and
follow normal safety procedures
before starting equipment.
CAUTIONS
These instructions are general in nature. It is assumed that the installer is familiar with seals
and certainly with the requirements of their plant for the successful use of mechanical seals.
If in doubt, get assistance from someone in the plant who is familiar with seals or delay the
installation until a seal representative is available. All necessary auxiliary arrangements for
successful operation (heating, cooling, flushing) as well as safety devices must be employed.
These decisions are to be made by the user. The chemical listing is intended as a general
reference for this seal only. The decision to use this seal or any other Chesterton seal in a
particular service is the customer's responsibility.
2
DISASSEMBLY (1-6) – SMALL (1" to 2.5" [25 mm to 60 mm] shaft/sleeve)
For 155 seal, remove the tabs or the 478
or other gland before disassembling the
seal. Remove the tabs by removing the
tab retaining snap ring and pressing the
tabs towards the center of the hub gland
and then sliding them out. To remove
the 478 or other gland just pull the gland
away from the hub gland.
3
1
You will need the hex keys provided with
the seal, and an O-ring extractor or paper
clip to disassemble the seal.
4
2
Place the seal, lock ring side up, on a flat
surface. Back out all the screws from the
sleeve. Remove the lock ring. Remove the
centering strap.
5
While holding the sleeve and gland together,
turn the seal assembly over and lift out
the rotary and the sleeve, separating the
stationary face from the rotary face with your
fingers. Turn the faces in opposite directions
if it becomes difficult to separate them.
6
Remove the back-up washer and
stationary drive with the springs. Remove
the springs from the stationary drive.
Remove the rotary, rotary O-ring and
shaft O-ring from the sleeve.
Place the rotary and the sleeve next to
the gland assembly.
vÌÊÕÌÊÌiÊÃÌ>Ì>ÀÞÊ>`ÊÀiÛiÊÌiÊ
dynamic O-ring.
3
ASSEMBLY (7-14) – SMALL (1" to 2.5" [25 mm to 60 mm] shaft/sleeve)
7
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silicone grease provided and install it in
ÌiÊÃiiÛiÊ°°Ê}ÀÛi°ÊÕLÀV>ÌiÊÌiÊ
rotary O-ring and install it in the sleeve
O.D. groove.
10
8
Slide the rotary onto the sleeve, aligning
the drive tabs with the rotary slots. Slide
the rotary over the O-ring until the rotary
bottoms out. Check to make sure the
drive tabs are properly engaged.
11
9
Place a spring in each hole in the stationary
drive. A small amount of silicone grease can
be applied to the bottom of each spring.
This will help the springs stay in the holes.
12
Place the hub gland assembly with the
gasket side up, on a flat surface. Align the
slots in the stationary drive with the tabs
in the hub gland. Slide the stationary drive
in until the springs touch the hub gland.
Place the back-up washer in the hub
gland. It will rest on the stationary drive
until the seal is compressed.
13
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stationary. Slide the O-ring onto the
stationary. Slide the stationary into the
hub gland until it engages the stationary
drive. Be sure to line-up the drive tabs
with the stationary slots.
Turn the assembly over and place with
the lock ring side of the sleeve up, on
a flat surface. Place the lock ring over
the sleeve, lining up the flat head socket
screws with the smaller holes and the cup
point set screws with the larger holes.
Press down on the lock ring and tighten
the flat head socket screws and the cup
point set screws. Check to ensure that
the sleeve is not deformed while tightening
the set screws. Make sure the screws do
not protrude into the sleeve I.D. bore.
Wipe the stationary and rotary faces clean
with a lint free cloth. Place the hub gland,
with the stationary installed, stationary side
up on a flat surface. Place the stuffing box
face gasket in the hub gland. Slide the
sleeve, with the rotary installed, downwards
into the hub gland. Pick up the hub gland
and sleeve and continue to push them
together until the faces contact each other.
14
Press down on the hub gland and push
the centering strap through the slot in
the hub gland. Push the strap in until it
completely surrounds the seal sleeve.
It will pilot between the hub gland, seal
sleeve and lock ring.
4
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