Goulds Pumps 3996 - IOM - Manual (Page 34)

s
! WARNING
Never operate the pump without liquid supplied to
mechanical seal. Running a mechanical seal dry,
even for a few seconds, can cause seal damage and
must be avoided. Physical injury can occur if
mechanical seal fails.
PACKED STUFFING BOX
!
Packed stuffing boxes are not allowed in an ATEX
classified environment.
Packing operation can be inspected without shutting
down or disassembling the pump. During normal
operation the packing should leak approximately one drop
per minute. If the drip rate is higher or lower than one
drop per minute then an adjustment of the gland may be
required. To slow down the leakage rate, the two gland
bolts should be tightened evenly one-quarter (¼) turn
each until the desired leakage rate is obtained. NEVER
over-tighten packing to the point where less than one drop
per minute is observed. Overtightening can cause
excessive wear and power consumption during operation.
If the packing cannot be tightened to obtain less than two
drops per minute, then the packing may need to be
replaced and the packing installation procedures under
Operation should be followed.
$
! CAUTION
Never attempt to replace packing until the driver is
properly locked out and the coupling spacer is
removed.
DYNAMIC SEAL
!
Dynamic seals are not allowed in an ATEX
classified environment.
Dynamic Seal Components
Repeller - The dynamic repeller effectively prevents
leakage of pumpage through the stuffing box when the
pump is operating under published acceptable conditions.
Dynamic seal parts do not wear substantially to affect
operation unless the service is particularly abrasive or
corrosive. Refer to Disassembly and Reassembly Section
for maintenance, disassembly, and repair.
Static Seal - A static seal is used to prevent leakage when
the pump is shut down. This is either a lip seal,
elastomeric face seal, or graphite packing. The lip and
elastomeric face seal require no maintenance other than
replacement when leakage becomes excessive. The
packing should be installed as stuffing box packing. It is a
special type designed to run dry, so it does not require an
external flush.
30
3996 IOM 9/2010
Fig. 13
Dynamic Seal with Packing
Fig. 14
Dynamic Seal with Chekseal™