Edwards APGX-H, Instruction Manual, Page: 13 / 32

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Installation
D023-92-880 Issue F
3 Installation
3.1 Unpack and inspect
Remove all packing materials and protective covers and check the APGX-H.
If the APGX-H is damaged, notify your supplier and carrier in writing within 3 days: state the Item Number of the
gauge together with your order number and your suppliers invoice number. Retain all packing materials for
inspection. Do not use the APGX-H if it is damaged.
If the APGX-H is not to be used immediately, replace the protective covers. Store the APGX-H in suitable conditions
as described in
Section 6 .
3.2 Fit the APGX-H to a system
CAUTION
Do not use the electronics housing to tighten the
1
/
8
inch NPT gauge to a vacuum system. This could permanently
damage the electronics.
Note: To ensure compliance with the rated EMC immunity specifications, you must ensure the APGX-H tube is
electrically connected to an earthed vacuum system.
The APGX-H can be mounted in any orientation however the gauge tubes are individually factory calibrated in
nitrogen whilst vertical. For correct pressure indication in your chosen gauge orientation, the gauge should be
recalibrated at atmospheric pressure. Edwards recommends mounting the gauge tube vertical in order to minimise
the build up of process particulates and condensable vapours within the gauge.
For optimum accuracy it is recommended that both the atmosphere and vacuum adjustment is carried out before
use. Refer to
Section 5.1 for information on atmosphere and vacuum adjustment.
To connect the APGX-H to your vacuum system:

Use an 'O' ring / centring-ring or Co-Seal and clamp to connect an APGX-H with an NW16 or NW25 flange to a
similar flange on the vacuum system.

Use a stepped 'O' ring carrier or Co-Seal to connect an APGX-H with an NW16 flange to an NW10 flange.

Wrap several layers of PTFE tape around the NPT coupling on the APGX-H
1
/
8
inch NPT tube. Gently screw the
tube into the female NPT fitting until finger tight. Using a
5
/
8
inch spanner on the base of the tube, rotate
the tube approximately 1 turn to achieve a vacuum seal.
WARNING
You must use a Co-seal or trapped ’O’ ring carrier to connect an APGX-H with NW flanges to a
vacuum system if the pressure is likely to exceed atmospheric pressure.
Standard centring rings are not suitable for use above atmospheric pressure.