Goulds Pumps AF (Axial Flow) (42"/1200mm/54/60"/66") LM/LMR Bearings - IOM" - Manual (Page 61)

AF (42-66) IOM 61
APPENDIX 1
SPECIAL PACKING
ARRANGEMENT
(High pressure, dual flush packing)
The following information covers the installation,
operation and maintenance of the high pressure, dual
flush packing arrangement. This arrangement was
developed for high pressure, to minimize product
dilution, and to minimize external packing leakage.
DESCRIPTION
The arrangement consists of (6) rings of packing
(106), (2) lantern rings (105), and (1) restrictor
bushing arranged as follows: 3P, 1L, 2P, 1L, 1P, 1RB
from the gland face to the bottom of the stuffing box,
See fig. 24 below.
The inner lantern ring uses product flush to minimize
product dilution. This flush should be filtered to
reduce particle size and minimize sleeve / packing
wear.
The outer lantern ring is supplied with water and is
used as with any other packing arrangement to
lubricate and cool the packing as the shaft rotates
and generates heat.
The flush pressures should be 10% higher than the
pressure inside the pump. For end suction pumps
this will also include pump discharge pressure.
Product flush pressure to the inner lantern ring may
be slightly less than the water flush pressure to
ensure flow toward the inside of the pump.
The flush flow depends on the application, the more
heat generated the higher the flows must be to
effectively remove the heat. The table below can be
used as a starting point for initial setting: The table
below represents the flow required with one flush line,
for a dual flush arrangement the flow can be divided
up equally.
The stuffing box is furnished with (2) inlet and (2)
outlet ports for piping of the flush liquid. The inlets are
chosen based on shaft rotation direction so the flush
flow travels the longer route to the outlet ports (see fig
25). The outlet ports may be plugged, but for
improved cooling of the sealing elements, outlet pipes
are installed to allow more flow through the stuffing
box. With this setup flush flows are regulated by a
valve on the outlet line rather than by throttling the
flow on the inlet li ne
Fig. 24
Sleeve dia. Flush flow
(inches) (gpm)
2 .05
3 .15
4 .30
6 1.3
8 2.5
10 5.0
12 8.0
Inlet Outlet
8