Edwards Diffstak 63/150 - Recommended Pump Fluids; Schematic Diagram of Typical Pneumatic Circuit (P-Model Pumps Only)

B344-21-880 Issue N
Page 28 © Edwards Limited 2007. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Installation
3.9.2 Recommended pump fluids
Take note of the information given in Table 2 about the thermal breakdown temperature and decomposition products
of the various pump fluids. Choose the best fluid for your application. Use Santovac 5 for the cleanest high-vacuum
systems.
A cooling-fail thermal snap-switch is available as an accessory; this switch may be used to prevent the pump from
overheating if the cooling-water supply fails.
Figure 17 - Schematic diagram of typical pneumatic circuit (P-model pumps only)
WARNING
Do not use perfluoropolyether (PFPE) pump fluid in the Diffstak pump. The thermal breakdown
temperature of PFPE fluids is near the operating temperature of the Diffstak pump. The thermal
breakdown products of PFPE fluid are very dangerous.
WARNING
If you use polyphenyl ether (PPE) pump fluids in the Diffstak pump, you must fit a cooling-fail
thermal snap-switch and interlock it with the pump electrical supply. If you do not, the thermal
breakdown temperature of the fluid could be reached if the cooling-water supply fails. The
thermal breakdown products of PPE fluids are dangerous.
1. Pneumatic supply
2. Shut-off valve
3. Filter
4. Pressure regulator
5. Lubricator
6. Standard 5-port control-valve
7. Electrical connections
8. Diffstak high-vacuum isolation-valve (fail-safe
closed installation)
9. Diffstak high-vacuum isolation-valve (fail-safe open
installation)