Important Points Regarding Vacuum Pump Choice
Elevation Correction Coefficient
The degree of vacuum of the pump affected by elevation will be lowered by the amount of the correction factor.
| Elevation (m) | Correction Value (kPa) |
|---|---|
| 100 | 1.2 |
| 200 | 2.4 |
| 300 | 3.6 |
| 400 | 4.7 |
| 500 | 5.9 |
| 600 | 7.0 |
| 700 | 8.1 |
| 800 | 9.3 |
| 900 | 10.4 |
| 1,000 | 11.5 |
Note that when operating under atmospheric pressure in areas of high elevation, there will be a difference in the actual degree of vacuum compared to operating under atmospheric pressure at sea level.
The following formula can be used to make the conversion.
Simplified Correction Formula for Ultimate Vacuum [kPa] = Written Operating Value (from the chart) [kPa]－Elevation [m] × 0.0115 [kPa/m]
Regarding the Performance Curves
Regarding the vacuum pump performance curve, the vertical axis shows the flow rate under intake conditions (i.e. the volumetric flow rate of the gas that is flowing through the pump intake port under pump conditions), as well as the flow rate under 1 atm (the volumetric flow rate of the gas that is flowing through the pump intake port under 1 atm). The volume of a given quantity of gas will differ in proportion to pressure, and therefore there will also be a great difference in the volumetric flow rate depending on differences in pressure. Keep this in mind when comparing pumps.
When the exhaust speed(※) is indicated on the vertical axis, please make a comparison with our pumps while viewing the flow rate under intake conditions.
※ Exhaust Speed: An standard indication of vacuum pump size and capacity, defined by the overall volumetric flow rate of gas that passes through the pump intake port.
The performance curves for the KCP/KCE/KCM models are share the same two flow rates.
Case of KCP100-V-01A:
Regarding Piping Resistance
In order to use a vacuum pump at its ultimate vacuum, we ask our customers to take into consideration the piping to the vacuum pump and their equipment. If piping circuits are long or if piping diameters are small, pressure losses can result, and pumps can fail to perform at their full capacity. Using piping of diameters that are the same size or larger than the connection ports on the pump, and making piping lengths as short as possible can reduce pressure losses (from piping resistance).
Energy Saving Case for the KCE Vacuum Pump (For a Vacuum Molding Machine)
We will introduce a case where a customer that operates a plastic molding machine changed from a liquid ring pump to 2 KCP150D-V2 basic oil-free vacuum pumps. Initially, this customer ran 2 molding machines from a single liquid ring pump under a centralized piping system of 25 m of long thin piping. To this, we proposed 1 pump for each molding machine, and decentralization of the piping. A KCP150D-V pump was installed near each of the molding machines. Piping lengths of approx. 5 m contributed to improved pump performance and motor output was cut in half compared to what it was before the renovation. Reviewing piping allows for use of the optimal pump and overs energy saving results.
| Before Renovation | After Renovation | |
|---|---|---|
| Conditions | 2 molding machines supplied by a single pump※, and 25 m of long, thin piping. | 1 pump per molding machine※ and piping of sufficient diameter at a length of 5 m. |
| Vacuum Pump | Liquid Ring Pump | 2 KCP150D-V Units |
| Motor Output | 15kW | 7.4 kW (3.7 kW × 2 units) |