Helium Leakage

[narejo]

A recent problem we have faced at one of our locations where a Daniel GC is installed , we replaced the columns and 6 port valve kit with new one, but found leakege of Helium , however we doubled checked all the fittings including the columns as well but no external leakeges were observed, and we pluged the vents to still be sure then we observed that there is no drop in the pressure which made us sure that there is no leakeges externaly.
So what would it be, imean what should we attempt now.
Sould we go for the Kit or the columns
Chromatogrpher1 iwill specially wait for your reply.
So any one who can give any opinion it will highly be appreciated.

narejo

[chromatographer1]

You did not mention which model of Daniel GC you have. I will assume you have a 3 six-port valve system commonly used for BTU pipeline analysis. Correct me if I am mistaken.

You said I believe that you closed off the detector vent.

There was no pressure loss after turning off the helium supply? The pressure gauge did not drop with time?

I assume you did not test for leaks with a sealed system at each position of the valves. You should check. A valve may leak at one position but not another. If you are not loosing helium with the detector vent closed with the system at operating temperature at all valve positions then you do not have a leak.

Have you checked your gauges for leaks?

Tell us how you believe you have a leak in the system if that is the case.