Wright Flow Technologies 114, Инструкция по установке, эксплуатации и обслуживанию

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Installation, Oper ation & M aintenance M anual
TR-C Series Centrifugal Pump
12
TR-C-
M02
A
SS
EM
B
LY
4. ASSEMBLING AND INSTALLING THE MECHANICAL SEAL
MECHANICAL SEALS. Among the TR-C, TR-C plus, and IC plus pump series, there exist
five types of mechanical seals.
One of these, the “
T21
”, is used exclusively with our IC+ series; specifically, in non-sanitary
applications. As for the remaining four types, their selection must be based upon the
application and the properties of the fluid being pumped.
The
“
D
” seal is the most common mechanical seal. It is used when the process fluid is neither
corrosive nor abrasive. It is a balanced, external seal, designed to be long- lasting.
The “
F
” seal is exactly the same as the “
D
” seal, but contains a water-cascade assembly to
lubricate and cool the seal. The water-cascade assembly is located on one side of the adapter.
This seal, although it is sanitary, is very dirty because the coolant tends to drip.
The
“
DG
” seal consists of two parts: one stationary and other rotating. The rotating part consists
of the same elements as the “
D
” seal. The stationary part consists of one piece made of
silicone, ceramic, or carbon tungsten, and which is placed in a gland ring. This type of seal
is used when the fluid to be pumped is abrasive, corrosive, or contains a product which
impedes the seal lubrication. The stationary seal is made of a very strong material and is
reversible; allowing for the seal to be utilized multiple times.
The
“
E
” seal is a double-balanced seal that is cooled by water. This seal is composed of a
stuffing box which is filled with fluid (normally water) to cool the mechanical seal. The
“
E
” seal
is used in conditions similar to those of the
“
DG
” seal, but in applications that handle extremely
high temperatures (up to 500º F). It can also be used in applications where there exists a
vacuum of up to 28 in. of mercury.
EXTERNAL-
BALANCED SEAL TYPES “D” AND “F”.
Locate the following pieces: carbon
( 80 ), o-ring ( 80B
), “D” seal cup (
80A
). “D” seal spring (
80C
), “D” seal drive collar (
80L ), set
screws ( 80K
), and “D” seal backplate (
11 ). Pre-assemble the set screws, making sure they
do not penetrate the inner diameter of the stub shaft and set the o-ring into the carbon so
that it sits at the back. Next, place the o-ring and carbon together onto the cup so that the
cup’s
three legs align with the
carbon’s slots. Then, fit the spring onto the cup so that the tip of the
spring is touching a fourth, folded leg on the cup. If necessary, rotate the spring to touch the
two pieces. When handling the carbon (
80 ), be careful not to bump or scratch the seat of the
seal, as this is the face that makes the seal.
For best assembly, the drive collar has a pin or key that
should fit into a slot in the cup. Use pressure to insert
the drive collar, making sure that the pin aligns with the
slot as shown in
Figure C.
Slide the entire assembly onto the stub shaft.
The o-ring seals the flow of fluid through the
mechanical seal between the pump and the exterior
by filling the space between the stub shaft and carbon.