rosemount 3051 sd

[kithks]

hi ,
i have a same kind of diaphragm seal mounted transmitter problem .
i have a tank (hydro carbon) call slop ,lighter fluid sg=.98

i have this rosemount 3051sd ,capillary transmitter mounted 28 " above low tap .i am measuring 146" span.

per the calculatio, i got my lrv as -106.2 urv as -59.22

when i put this back on service, still i am getting a zero shift about 15 % higher than the normal reading ......
am i doing something wrong ?
it should read ZERO(0) when it (flanges) open to the atmosphere ?


thanks,

kithks

 

[danw2]

What's the fill fluid in the capillary and its S.G.?

 

[danw2]

If the physical span (elevation) is 146" at a specific gravity of 0.98, then your span should be 143.1"

With a LRV of -106.2" and URV or -59.2", the span is only 46.0", off by a whole lot.

Do you mean a URV or +59.2? That would be a span of 165.4", still too large for the values given.

The LRV and URV values don't make sense.

What is the elevation distance between the center of the lower flange and the center of the upper flange? Your liquid span might be 146" but the flanges might be 180" apart, and gravity's pull on the fill fluid makes a difference in the LRV and URV calculation.