Flange Joint Live Tightening

[TXY]

Hi guys,

Looking for advice on performing live tightening on flange joint at 120degC. Prior to start up, it was torqued with the recommended 4 torque passes (30, 60, 100, 100% check). It has been some time since start up and the end user contacted to perform live tightening. My question is whether it is still necessary to perform 4 torque passes for live tightening. Or a clockwise check pass with 100% torque would suffice. Thanks in advance.

Cheers
XY

 

[LittleInch]

Doing anything to a live system has a significant increase in risk compared to doing anything to one which is not live.

Why does the end user think it need checking?

Is it leaking?

 

[NovaStark]

Hi guys,

Looking for advice on performing live tightening on flange joint at 120degC. Prior to start up, it was torqued with the recommended 4 torque passes (30, 60, 100, 100% check). It has been some time since start up and the end user contacted to perform live tightening. My question is whether it is still necessary to perform 4 torque passes for live tightening. Or a clockwise check pass with 100% torque would suffice. Thanks in advance.

Cheers
XY

Much like what LI says, if it isn't leaking, there wouldn't be any need to do an online tightening as that could impart more damage than benefit.

Is this a known problematic joint or operates in some condition where bolt relaxation is a sigifnicant issue ? 120 degC doesn't seem like a large enough temperature to cause it.