Materials/Options
Pump
housing components and drive and idler gear shafts are available
in two types of austenitic stainless steels - 316 and Alloy
20 - and high-nickel Alloy C. All housings are investment-cast
and precision machined for high quality and durability.
Gears
A broad selection of metallic and non-metallic gears are
available to meet a wide variety of process conditions.
This includes
non-sparking, gall resistant Alloy C. Alloy 20 316 stainless
steel is also available. Where conditions do not allow
metal-to-metal
contact, glass-filled Teflon, carbon graphite, and PEEK (polyetheretherketone)
can also be used as gear materials. In conjunction with
a metallic
drive gear, these materials allow extended life at full-speed
operation even with fluids with viscosities less than
1 cps.
Wearplates
Wearplates are used on ECO Gearchem pumps to permit easy restoration
of a pump to "like-new" performance.
Carbon graphite
wearplates are used most often since they are suitable for
all pump speeds over the full range of viscosities and temperatures.
Additional materials include glass-filled Teflon, PEEK, and
ceramic which are used in certain applications, such as
those
where exposure to strong oxidizers makes carbon graphite
unsatisfactory.
Bearings
Bearings used in ECO Gearchem pumps are of the internal sleeves
type and are colled and lubricated by the pumped fluid.
This
eliminates the risk of contamination from external lubricating
materials. Carbon graphite and glass-filled Teflon are
offered
because of their proven durability and inherent self-lubricating
properties.
Mechanical
Seals
Our pump seals prevent or minimize product leakage and ingress
of air to the process stream. Selection of the seal arrangement,
probably the most important step in pump specification, depends
upon suction pressure, discharge pressure, viscosity, and
other fluid characteristics and type of service.
ECO
Gearchem pump allow for quick and easy conversion in the field
from one type of seal to another, if required, without special
tools or training.
Three
types of seal and packing arrangements are available for ECO
Gearchem pumps:
- internal mechanical seals (single or double)
- external mechanical seals (for pressure or vacuum service)
- and mechanical packed boxes (standard and lantern ring)
Mechanical
seals on Gearchem pumps are of the John Crane type 9 design.
Primary sealing is accomplished by the lapped surface of the
stationary sealing wedge. Teflon O-rings or gaskets seal the
stationary seat against the seal housing.
The
single internal mechanical seal is suitable for all recommended
pump operating pressures and temperatures to 250 F (121 C).
For fluids that tend to crystallize or precipitate, or for
vacuum or high temperature applications, a double mechanical
seal is often used.
An
external mechanical seal is mounted outside the pump housing.
This arrangement permits easy adjustment and inspection
of
the seal faces. The addition of a housing extension precludes
a vacuum seal for operating pressures as low as 0.1 mm Hg
abs.
The
mechanical packed box designs use braided Teflon or Graphoil
rings to control leakage along the shaft.
Options
Under
certain process conditions, special options are required to
insure that the pump operates satisfactorily. We offer design
features such as:
- Bearing flush ports -for thin non-lubricating fluids
to increase lubrication to bearings
- For viscous fluids ( < 2000 cps)-use to flush bearings
when pump is taken out of service
- PFA coated SS O-rings and metallic bearing lock pins -
Use for high temperatures ( > 250 F, 121 C)
Use for low temperatures ( < 0 F, -18 C)
Use for vacuum service
Use for variant temperatures
- Center Housing Vent -
Use for applications that have a tendency to entrain gas
- Special Hardened Carbon Bearings and Shafts -
Used for thin non-lubricating liquids
Helps prevent premature wear of bearings and shafts
Commonly used with bearing flush ports
- Other options available upon application requirements
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