Gearchem 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.


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

For more information, please visit the Pulsafeeder website or call us at 302 655 3490.