９
Pressure in practice is higher than that noted in the catalogue for the following reasons.
(1) The fact that the vacuum gauge is mounted a distance from the pump, the steam
generated by water droplets and rust etc on the inside walls of the pump and piping, and
a variety of gases present in the system result in increased pressure.
(2) Leaks into the vacuum system introduce other gases, resulting in increased pressure.
5.2 Pumping Speed
Pumping Speed varies with the type of gas used, and its pressure. The maximum Pumping
Speed is reached when air is introduced, and slowly decreases as pressure is reduced.
The resistance of the piping system increases with small bore piping which extends over long
distances, and this reduces the rate of evacuation.
The declared Pumping Speed for this pump is the maximum value achieved with dry air.
5.3 Power Requirements
The power required to operate the pump is the total of the work required to overcome the
rotational resistance of the pump (mechanical work), and the work required to compress the
air (compression work)and is at a maximum at an inlet pressure of 5.0 x
10
４
-
7.0 x
10
４
Pa.
If pressure drops below this level, compression work is considerably reduced and power is
expended in mechanical work.
6. Maintenance, Inspection, and Repair
6.1 Cautions for Maintenance, Inspection, and Repair
See "Danger" (3) on p.04.
See "Warning" (5), (19) and (20) on
p.04 and p.05.
See "Caution" (8) and (9) on p.06.
See "Note" (8) on p.07.
Customer repair technicians are able to perform the following maintenance and repairs. Other
repairs and modifications (except for the standard options available from the manufacturer)
should not be performed by the customer.
1) Replace the cylinder gasket, cup packing
2) Replace the inlet / outlet valve
3) Replace the O ring
4) Replace the Head gasket
!
Danger
!
Caution
!
Note
!
Warning
