SHURflo 316 Stainless Steel Rotary
Close-Coupled External Gear Pumps
10
SHURflo Operating Instructions, Performance,
Specifications and Parts Manual
Viton Models GMSV2A, GMSV4A, GMSV6C, GMSV2A3T, GMSV2A33T,
GMSV4A5T, GMSV4A53T, GMSV6C7T and GMSV6C73T
Teflon
®
Models GMST2A, GMST4A, GMST6C, GMST2A3T, GMST2A33T,
GMST4A5T, GMST4A53T, GMST6C7T and GMST6C73T
Form L-4089 (2/17)
Figure 8 - Shaft, Seal and Bearing Assembly
Figure 9 - Shaft, Seal and Bearing Assembly (detailed view)
seal cavity on start-up. The dry
running of a mechanical seal
will cause rapid failure. A flush
must be provided for fluids with a
viscosity of greater than 2000 SSU.
Pumping fluids with
viscosities greater than
2000 SSU requires
flushing the seal chamber during operation,
otherwise seal damage
will occur.
EXTERNAL FLUSH
An external flush system is typically
recommended for applications where
crystallization build-up on the seal is
possible. Some dilution of the working
material must be acceptable to use an
external flush system.
The external flush system (See Figure
6 for typical installation) is commonly
used with liquids where city water can
be used as the neutral flush fluid. City
water is taken from an external source
such as a tap, hose, or special plumbing
fixture and is regulated into the seal
cavity by means of a needle valve and
flow meter. Use of an anti-siphon check
valve is required.
Operation (Continued)
It is essential that an
anti-siphon check
valve be installed
between the pump and the city water sup-
ply to prevent any back flow from possibly
contaminating the city water supply. Failure
to do so could result in contamination of the
water supply with consequential damages.
Manufacturer assumes no responsibility for
failure of user in not providing safeguards to
city water systems.
Step 1: Locate appropriate city water sup-
ply and install anti-siphon check valve.
Step 2: Use appropriate pipe nipple to
reduce piping to 1/8”.
Step 3: Install appropriate needle valve
and flow meter.
Step 4: Connect piping to one of three
available seal flush ports on pump.
Step 5: Adjust needle valve to achieve
desired flow to seal cavity (recommend-
ed 1 to 3 GPH).
INTERNAL FLUSH
Similar to above but internal supply
(See Figure 7 for typical installation).
Typically recommended for high viscos-
ity applications ensuring lubrication to
the mechanical seal.
In an internal flush system, the fluid is
taken from the discharge and regulat-
ed from 1 to 3 GPH (Gallons Per Hour)
to the seal cavity by means of a flow
meter and needle valve.
Gear Pump Body
Shaft, Seal,
Bearing Assembly
O-ring
Retaining
Ring
Retaining
Ring
Retaining Ring
Mechanical Seal
Seal Seat Retainer
Retaining Ring
Bearing
Shaft
Seal
Retaining Pin
