K465i Operations and Maintenance
P/N 1212831 Rev C
Page 5-161
Copyright
©
2012
Veeco Instruments, Inc. Confidential
All Rights Reserved
METHODOLOGY
All systems must be leak checked prior to flowing any gases through them. This involves
leak checking all plumbing, VCR fittings, joints, manual, pneumatic and needle valves, mass
flow and pressure controllers, joints and weldments, the transfer hub chamber and the
growth chamber. Additionally, you must be constantly aware that pressurized conductors of
gases and liquids flow from vessel to vessel, through connections in valves and MFCs, and
large and small components. The effects of leaks and leak repairs can be found in changes
in pressure and additional leaks, before and after leak points.
The following procedures are a basic guide to leak checking. The procedures outline, in
general, the fundamentals of how leak checking should be performed. Due to the complexity
of identifying, and describing, specific instructions for the entire system, explicit details for
leak checking all parts of the system are not provided. Instead, the information presented is
intended to assist technicians in developing a methodology for leak testing. This
methodology should be applied every time any part of the system requires leak checking.
Successful leak testing requires careful, methodical work. Following an organized sequence
of steps helps locate leaks with a minimum of confusion. Take your time. Work sequentially.
Have a plan.
Notes:
The whole system, or entire gas panel, should not be leak checked as one unit. It should be
broken down into smaller sections
Leak checking using a standard leak detector is only valid for parts that run under vacuum.
Parts that run under pressure should be pressure-tested. Instructions for pressure testing
are contained in the appropriate maintenance procedures.
Read the leak detector operation manual prior to operation.
Warning!
Thoroughly read and understand all Warnings and Cautions listed in the
Safety Precautions and Hazard Management list before performing any leak checking tasks.
HELPFUL HINTS IN LEAK-CHECKING
The following helpful hints will simplify leak checking of a system and its components:
Turn off laminar flow unit if applicable.
Keep the area where you are performing the leak checking free of drafts and fans.
