Instruction manual

The gas-ballast boost pipe has a non-return valve, however some of the process gas pumped can

leak through the valve if you are rough pumping (above an inlet pressure of 650 mbar,

6.5 x 10

Pa).

If you will pump dangerous substances, we therefore recommend that you use a bottled nitrogen

supply or a closed system; refer to Section 3.9.3 to connect the nitrogen supply.

3.9.3 Connect the nitrogen supply (if required)

WARNING

When you connect a nitrogen supply to the gas-ballast boost pipeline, install a suitable

pressure relief system if your vacuum system is not suitable for pressures above

atmospheric pressure. If you do not, the pressure in your system could rise to the pressure

of the nitrogen supply.

When necessary, you can connect a nitrogen supply to the gas-ballast boost system so that

nitrogen is delivered to the DP180 instead of air.

Use the following procedure to connect your nitrogen supply.

1. Refer to Figure 3. Undo and remove the NW10 clamp (7) which secures the air-filter (8) to the

gas-ballast boost pipe. Remove the air-filter.

2. Connect your nitrogen supply to the gas-ballast boost pipe through an NW10 adaptor. Your

nitrogen supply must meet the specification given in Section 2.

3. Fit the NW10 clamp (removed in Step 1) to secure the adaptor.

3.10 Evacuation of the bearing end-cover (optional)

If you want to use an external evacuation pump to evacuate the bearing end-cover, use the

following procedure to connect the pump:

1. Remove the six fixing-screws which secure the bearing end-cover to the high vacuum

head-plate (see Figure 10).

2. Lift away the end-cover and carefully remove the sealing 'O' ring.

3. Use a suitable tool to prise the felt filter out from the head-plate.

4. Apply a light wipe of sealing compound to a

inch BSP tapered plug and fit the plug to the

head-plate.

5. Check the condition of the 'O' ring removed in Step 2. If the 'O' ring is damaged, replace it

with a new 'O' ring.

6. Apply a light wipe of PFPE grease to the 'O' ring and place it in its groove on the head-plate.

Refit the bearing end-cover to the head-plate.

7. Remove the

inch BSP taper-plug from the bearing end-cover.

18 DP180 Dry Vacuum Pump