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Turbo vacuum pumps: Edwards (formely known as BOC Edwards) turbomolecular vacuum pumps

Edwards vacuum (formerly BOC Edwards) Turbomolecular pumps: EXT255DX compound turbomolecular pump

Edwards (formerly BOC Edwards) Vacuum - Turbo pumps and accessories

EXT turbomolecular pumps

EXT75DX compound turbomolecular pump
EXT255DX compound turbomolecular pump
EXT255H compound turbomolecular pump
EXT406PX compound turbomolecular pump
EXT556H compound turbomolecular pump

Turbomolecular pump controllers

Edwards Vacuum: EXC controllers
Edwards Vacuum: TIC turbo controller
Edwards: TIC turbo & instrument controller

EXT accessories

Edwards EXT accessories
EXT pump to controller cable
EXT ACX air-cooler
EXT BX bakeout band
EXT PRX10 purge-restrictor
EXT TAV vent-valve
EXT Vent-port adaptor
EXT Vibration isolator
EXT VRX vent-restrictor
EXT turbo pump spares

EXPT combined outfits

Edwards EXPT 1 &2 pumping stations

STP magnetically levitated turbomolecular pumps and accessories

Edwards Vacuum - STP turbo pumps
STP-XA4503C turbomolecular pump
STP-iX455 turbomolecular pump
STP301/STP301C turbomolecular pump
STP-L301/STP-L301C turbomolecular pump
STP603/STP603C turbomolecular pump
STP1003/STP1003C turbomolecular pump
STPH301C high performance turbo pump
STPH451C high performance turbo pump
STPA803C "advantage" turbo pump
STPA1303C "advantage" turbo pump
STPA1603C turbomolecular pump
STPA2203C "advantage" turbo pump
STP-XA2703C turbo pump
STP-XA3203C turbo pump

Edwards turbo molecular pumps (turbo vacuum pumps) overview, information and definitions

Our range of EXT turbomolecular and compound molecular pumps and EXC Controllers uses state-of-the-art technology to provide reliable, high and ultra high vacuum.

EXT255DX compound turbomolecular pump

Edwards EXT255DX compound turbomolecular pump - Features & benefits

Compatible with TIC Turbo and Instrument Controller
Multiple communication modes available

Parallel mode allows traditional control signal interface

Serial mode allows RS-232 interface

Numerous user configurable parameters via RS-232 interface

Vent valve control settings

Normal speed indication

Stand-by running speed

Programmable power settings

Power consumption

Pump temperature

Enhanced monitoring capability including pump speed, power and temperature

Edwards EXT255DX compound turbomolecular pump - Technical data

Inlet flange: DN100ISO-K, DN100CF
Compression ratio

N2: >1 × 108
He: 4 x 105
H2: 1.6 x 104

Outlet flange: DN25NW
Interstage port (Hi variants): DN25NW
Recommended backing pump*: RV3
Vent port: 1/8 inch BSP female
Purge port: 1/8 inch BSP female
Maximum continuous inlet pressure (light gas pumping)**

water cooling (water at 15 °C, ambient temp at 40 °C): 5 × 10-3 mbar
forced air cooled, 35 °C ambient: 5 × 10-3 mbar

Nominal rotational speed: 60000 rpm
Standby rotational speed: Variable from 33000 to 60000 rpm (42000 rpm default)
Start time 90% speed:*** 80 s
Cooling method: Forced air / water
Ambient air temperature for forced air cooling: 5-35 °C
Minimum cooling water flow rate (water 15 °C): 15 l h-1
Water temperature range: 10-20 °C
Maximum inlet flange temperature: 100 °C (CF version)
Operating attitude: Vertical and upright, through to horizontal
Noise level at 1 metre: <50 dB(A)
Maximum magnetic field: 5 mT
Recommended controller: TIC200 turbo or turbo and instrument controlled
Quiescent electrical power: 25 W
Interstage pumping speed (Hi variants): 10 L s-1

Inlet flange

DN100ISO-K

DN100CF

Pumping speed (l s-1)3

N2
He
H2
Ultimate pressure (mbar)
With rotary vane backing pump****
With diaphragm backing pump*****
Weight (kg)

220
230
180

<5 × 10^-9
<5 × 10^-8
6.25

220
230
180

<5 × 10^-10
<5 × 10^-9
8.6

* A larger backing pump may be required for maximum throughput. A suitable diaphragm
pump with ultimate <5 mbar may also be used.
** Above this inlet pressure, rotational speed drops to below nominal.
*** Power limit set to 160 W.
**** Ultimate pressure 48 hours after bakeout with 2 stage rotary vane backing pump.
***** Ultimate pressure 48 hours after bakeout with Pb <5 mbar (500 Pa)

Edwards EXT255DX compound turbomolecular pump – Pumping speed

EXT255DX turbo pump - pumping speed vs inlet pressure

Edwards EXT255DX compound turbomolecular pump – Pumping speed

Edwards EXT255DX compound turbomolecular pump – Throughput

Ext255DX turbo pump - throughput vs inlet pressure

Edwards EXT255DX compound turbomolecular pump – Throughput

Edwards EXT255DX compound turbomolecular pump – Dimensions

A Manual vent valve in vent port
B Podule
C Logic interface connector
D Backing Port
E Podule connector socket
F Allowance for right-angle cable connector
G Earth bond point

Edwards EXT255DX compound turbomolecular pump - Ordering information

Product description                                                                        Order No.
PumpInlet flange
EXT2555DX ISO100                           DN100ISO-K                    B75311000
EXT255DX CF100                              DN100CF                         B75312000
EXT2555iDX ISO100 (interstage)    DN100ISO-K (main)       B75313000
                                                                DN25NW (interstage)
Accessories Order No.
ACX250H air cooling accessory                                                   B58053160
WCX250 water cooling accessory                                                B73600121