Propose to not include a tightness verification leak test on all flanges in the hydrocarbon carrying systems. Flanges that are dismantled after leak test, left deliberately untested, or are not part of the leak test boundary shall be labelled as a "witnessed joint" and a procedure should be followed to ensure the flange is made leak tight.
When a witness joint is made, it will be supervised by a qualified piping engineer / supervisor to ensure the surface is clean, correct gasket is used, no scoring on surface or gasket is present, correct sequence and value of torque is applied, etc. A tag indicating the flange is a witnessed joint will be hung on the flange and at first start-up of the system, the joint will be monitored for any leaks. If no leak is detected, then a portion of the tag will be torn off and signed-off to its ITR.
Systems and interfaces completed offshore shall be tested as per company standard prior to commissioning / preparedness of introduction of hydrocarbons.