Internal Eccentric Gear Pumps

Internal gear pump direction of rotation:

*Supplied in both clockwise and Anti clockwise direction of rotation.                                                                                                                                  * Based on the direction of relief valve the orientation of suction valve can be determined.                                                                                                * The end cap of the pressure relief valve must always point to the suction port.                                                                                                                * Direction of rotation can be changed by switching the direction of pressure relief valve and wiring the motor to turn in opposite.

Internal gear pump flange position:

Pump casings can be turned through 8 different orientations to enable easy installation into numerous different pipework systems. Make sure that the pressure relief valve is pointing to the suction though!

Advantages of magnetic drive seal-less pump:

• There is no any seals, Hence zero leakage

• Since there is no any seals, the pump needs little maintenance

• Since there is no leak, the is extremely low risk of fluid and vapor emissions. Hence used to pump hazardous, flammable, explosive and toxic chemicals

• Self priming in nature

Internal gear pump working principle:

• Internal eccentric gear pump have only 2 moving components within the process medium.

• Positive displacement is achieved by filling the cavity between the rotary & idler gears.

• Fluid enters through the suction port, filling the cavity between the teeth of the gears.

• The crescent within the pump head then separates the fluid as the idler gear turns on the pump shaft.

• These four images demonstrate this operation in detail.

 

External gear pump operating principle:

• Similar in operation to the internal gear pump

• The positive displacement is achieved by the fluid filling the cavities between the gears.

• The fluid is then carried around the periphery or external areas of the gears until the casing is full filled.

• And the fluid is pushed out of the pump outlet under pressure

Difference between external and internal gear pump:

* INTERNAL: Bulky / Easy to clean and reassemble / Smaller outlet size / All gear designs are spur / suited for shear sensitive fluids    * EXTERNAL: Compact / Larger outlet size / Gear design include spur & Helical / Higher speed / Suitable for high pressure

 

The intended purpose of a By- Pass or Pressure Relief Valve (PRV) is to ensure that the pump and drive unit are protected from unnecessary damage that may be incurred during over- pressurisation which is mainly caused by closed valve operation or blockages in the discharge line. By- Passes can be either installed on the pipework and route fluid back to the suction of the pump or tank, in the form of a By- Pass Circuit, or indeed installed directly on the pump head, as detailed below. The By- Pass, when opened, relieves excess fluid and pressure from the discharge section of the pump to the suction side and effectively allow the pump to recirculate within itself until the blockage in the line has been cleared or closed valve opened to allow the process medium to carry on through the system and drop the pressure in the line to an acceptable level for the installed equipment.

As By- Passes are spring- loaded and adjustable, they can be tweaked in situ to cater for changing system or pump requirements.

Heating Jackets are used when the process fluid temperature needs to be maintained. Callisto Gear Pumps can be supplied with these fitted to the front cover alone or on the bearing bracket as well (Double Jacketed). Existing units can also be upgraded to have a heating jacket fitted to the front cover by a simple cover change. The 2 top ports are the hot water inlet / outlet and the bottom port is for discharge of condensed water.

Recommended Operational Checks:
Below is a list of recommended operational checks that will enable operators to extend the life of the pump and avoid
any unnecessary damage.
Regularly check the following:
* Noise, vibration and heat levels.
* Abnormal leakages.
* Flow Rates & Discharges Pressures to ensure that they are within the usual and expected ranges. Having a Flow
  meter and Suction & Discharge Pressure Gauges / Sensors are recommended.
* Elastic parts on the Coupling (if present).
* Electrical Current Draws on the motor. If higher than normal this is generally an indication of elevated discharge pressures or blockages within the pump or pipework.

Other Recommendations:
All valves on auxiliary systems should be OPEN.
* If the pump is equipped with a Packed Gland a certain amount of leakage (small drips) is expected. However, if
after prolonged periods of operation this leakage increases then tighten the nuts on the packing press until the
leakage level reverts back to normal. If the nuts are tightened fully then replace the packing gland.
* If the pump is Mechanically Sealed then no leakage should be expected. If leakage is detected then this indicates
that the mechanical seal faces have been damaged and the seal needs replacing. The lifetime of the seal is
application and usage dependent, if you are experiencing undesirable and low seal life please contact our sales or technical department for further assistance.