Installation and Use of Vacuum Pump
Downstream Interconnect Kit
for molbloc-S
®
P/N 401882
Installation Instructions
The use of a vacuum pump, connected downstream of
the molbloc-S
®
, increases the usable flow range of
each element. The purpose of this kit is to provide the
plumbing components required for the typical installation
of the molbloc-S system with the medium flow vacuum
pump, part number 401940 and 401883. This instruction
sheet is a guide to the recommended plumbing
interconnection between the molbloc-S test system
and the vacuum pump.
MOLBOX OVER-PRESSURE PROTECTION
Since the pressure in the test setup is directly connected
to the molbox, care must be taken to not exceed the
maximum operating pressure rating of the Reference
Pressure Transducers (RPTs) within the molbox.
The check valve included in this interconnection kit is
provided to prevent damage to the molbox and/or the
vacuum pump. In the event the pump looses power or
the user leaves the vacuum shut-off valve closed
during a calibration, this check valve will allow gas flow
to vent out of the system while keeping line pressure
below a damaging level.
The plumbing connected to the outlet of the check
valve is not included in this kit and is therefore the
responsibility of the installer. This plumbing should be
keep as short as possible and its diameter as large as
practical in order to minimize the restriction to the
venting gas flow. This will limit additional line pressure
build-up in the molbloc-S plumbing system.
molbloc-S Test Layout
Top View
1. Inlet Supply Regulator
2. Device Under Test
3. Check
Valve
4. Medium-Flow Vacuum Pump
(Installed Outside of Lab Space)
5. Vacuum Shut-Off Valve
When performing a leak test of a plumbing system that contains the ISO-KF Style Vacuum Flanges, do not exceed the
maximum operating pressure of the molbox, 600 kPa (87 psia) for molbox A700K models, 200 kPa (30 psia) for molbox
A350K models.
