Overview
The compact water-cooled Diffstak pumps with an integral cooled baffle offer exceptionally clean pumping with very low backstreaming, reduced outgassing, and a reduction in the number of elastomer seals required for installation.
The Edwards Diffstak 250 (ISO250 inlet) design has been proven over many years with thousands of pumps installed.
This pump has a pneumatically actuated high vacuum isolation valve and is supplied with: NW40 elbow, NW40 centering-ring, NW40 clamp, water pipe couplings and ferrules, inlet ISO 250 trapped ‘O’ ring.
The Edwards Diffstak 250 (ISO250 inlet) design has been proven over many years with thousands of pumps installed.
This pump has a pneumatically actuated high vacuum isolation valve and is supplied with: NW40 elbow, NW40 centering-ring, NW40 clamp, water pipe couplings and ferrules, inlet ISO 250 trapped ‘O’ ring.
Technical Data
| Pumping speed | |
| nitrogen | 2000 l s-1 |
| hydrogen | 3000 l s-1 |
| Min backing pump displacement* | 40 m3h-1 |
| Recommended backing pump | E2M40 |
| Recommended fluid | Santovac® 5 |
| Fluid charge (dry) | 500 ml |
| Inlet connection compatible with | ISO250 |
| Backing connection | NW40 |
| Cooling water connection | 10 mm compression fittings |
| Heater power | 2.25 kW |
| Min cooling-water flow at 20°C | 180 l h-1 |
| Pneumatic connections† | 6mm coupling x ¼ BSP male stud |
| Pneumatic actuating pressure | |
| Minimum | 2.4bar / 35psi |
| Maximum | 6.9bar / 100psi |
| Weight | |
| 250/2000M | 59kg |
| 250/2000P | 60kg |
* For maximum throughput
† 250/2000P only
US 8928 
GB 6387 
AU 5774 
CA 5755 
NZ 3336 
IE 3170 
BR 1107 
MY 719 
