OPTIMEX has established 4 main categories to designate the circulation of the pumped liquids in the canned motors.
In order to complete the designation of the API 685, OPTIMEX established its own designation (with the letter of the category followed by a number).
The table hereunder defines, from the table on the right, the circulations most commonly suggested to our customers.
On demand, we also propose a bigger variety of circulations, depending on the pumped liquids.
|
CATEGORY |
LETTER |
PUMPING TYPE |
|---|---|---|
| Normal | N | Clear liquid, non boiling, hot or cold |
| Overpressured | S | Clear liquid, boiling, hot or cold |
| Cooled | R | Clear liquid, hot |
| Filtered | F | Loaded liquid, hot or cold |
|
PRINCIPLE DESIGN |
DESCRIPTION OF THE CIRCULATION |
OPTIMEX REF. |
API.685 REF. |
LIQUID IN THE MOTOR |
|---|---|---|---|---|
 |
Injection in the motor from the hydraulic casing (at the impeller periphery), circulation through the gap, and return to the pump suction via the hollow shaft. |
N1 | Designation 1-S | Pumped liquid |
 |
Injection in the motor from the hydraulic casing (at the impeller periphery), circulation through the gap, and return to the pump casing, in between two impellers, via the hollow shaft. |
N2 | – | Pumped liquid |
 |
Injection in the motor from the hydraulic casing (at the impeller periphery), passage through the hollow shaft, overpressure by an auxiliary impeller, circulation through the gap and return in the hydraulic casing at the impeller periphery. | S1 | Designation 1-SD | Pumped liquid |
 |
Injection in the motor via an external pipe from the discharge nozzle, overpressure by an auxiliary impeller, passage through the gap and return in the hydraulic casing in high pressure zone at the impeller periphery. |
S5 | – | Pumped liquid |
 |
Injection in the motor from the discharge nozzle, overpressure by a large auxiliary impeller, passage through the gap and return to the discharge nozzle via an external pipe. |
S3 | – | Pumped liquid |
 |
Pumped liquid and motor liquid are identical and they slightly communicate in order to establish an equipressure between the 2 areas (high and low temperature). On the motor side the liquid circulates in an external heat exchanger, flow is established by an auxiliary impeller. A thermal barrier is built between the hydraulic casing and the motor (air or water). |
R1 | Designation 23-S | Pumped liquid |
 |
Injection in the motor from the discharge nozzle through a self-cleaning tangential filter, passage through the gap and return to the pump suction via the hollow shaft. |
F1 | – | Pumped filtered liquid |
 |
Injection in the motor from the discharge nozzle through a self-cleaning tangential filter, overpressure by a large auxiliary impeller, passage through the gap and return in the hydraulic casing in high pressure zone at the impeller periphery. |
F5 | – | Pumped filtered liquid |
 |
The liquid in the motor and the pumped liquid are compatible and communicate just slightly. A liquid circulates in the motor in a loop on an exchanger (flow is created by an auxiliary internal impeller to the motor). In order to avoid a pollution of the liquid in the motor, we inject a very low flow in the motor circuit from an external source (leak in the pump casing). Injection flow and pressure are determined by OPTIMEX. |
F4 | Designation 53-S | External liquid |
 |
A part of the liquid called « process flow » is discharged through a double casing around the motor, in order to evacuate the calories externally, and to complete the cooling of the internal circulation. A second part of the liquid is injected in the motor from the hydraulic casing (at the impeller periphery), then circulates through the gap, and is re-injected to the process flow at the front support bearing. |
SR6 | – | Pumped liquid |
