
B777-50-880 Issue D
Page 6
© Edwards Limited 2013. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Technical Data
2.6
Materials exposed to gases pumped
The following materials and component types are exposed to the gases pumped: aluminium alloys, stainless steels,
fluoroelastomer and nitrile O-rings, hydrocarbon lubricant, rare earth magnets, silicon nitride, phenolic resin and
carbon fibre epoxy resin.
Table 5 - Technical data
Parameter
EXT556H
Notes
Mass EXT556H DN160ISO-K
13.4 kg
Mass EXT556H DN160CF
21.2 kg
Mass EXT556HF DN160ISO-K
19.3 kg
Mass EXT556HF DN160CF
20.5 kg
Main inlet flange
DN160ISO-K/DN160CF
Outlet flange
DN25NW
Vent port
1/8 inch BSP
Purge port
1/8 inch BSP
Inlet pumping speed
*
N
2
540 l s
-1
He
580 l s
-1
H
2
500 l s
-1
Ar
510 l s
-1
Inlet compression ratio
†
N
2
>10
10
Pb < 20 mbar
He
10
8
Pb < 12 mbar
H
2
10
6
Pb < 7 mbar
Ar
>10
10
Pb < 20 mbar
Ultimate pressure
‡
CF
<10
-10
mbar
ISO
<2 x 10
-9
mbar
Minimum backing pump
displacement
12 m
3
h
-1
Recommended backing pump
RV12
Maximum continuous inlet pressure
(light gas pumping)
**
These pressures relate to the
aluminium envelope variant
B777-51-000. Performance will vary
for other pump variants when
air cooled.
Forced air cooled, 30 °C ambient
1.5 x 10
-3
mbar
Forced air cooled, 35 °C ambient
1.0 x 10
-3
mbar
Water cooling at 15 °C
2.0 x 10
-3
mbar