Tee fitting- valve and sight glass ok?

[tj-los]

I have been looking at everyones set up on their keggles and was wondering.. Is there really an issue to have a tee fitting 1/2" to a ball valve and a sight glass?. I notice everyone uses sight glasses as stand alone or they will typically have a tee fittings with a thermometer (digital or guage). is there an unwritten rule?

Thanks all,

 

[Bobby_M]

It,s not unwritten. The level will read wrong while you drain and you would have to cap the top to maintain siphon.

 

[wyzazz]

^^What he said.^^