METHOD OF CONTROLLING CLAMPING FORCE WHEN TESTING PIPELINE FITTINGS Russian patent published in 2010 - IPC G01M3/08 

FIELD: physics.

SUBSTANCE: method of controlling pressure when testing pipeline fittings involves putting caps with sealing rings on socket pieces of the pipeline fittings, sealing the gap between the caps in the clamping system with initial pressure, filling the cavity of the test pipeline fitting with test medium under pressure, subsequent reduction of pressure of the test medium to a minimum value, discharging the test medium from the pipeline fitting and taking the caps off the pipeline fittings. Clamping pressure is automatically maintained in accordance with the condition: , where S=(2·D_n ² d_m ²) is effective area of the hydraulic cylinder; P_cl is pressure in the clamping system; D_s is average diametre of sealing socket pieces of the pipeline fittings; D_p is diametre of the piston of the clamp hydraulic cylinder; d_p is diametre of the plunger of the clamp hydraulic cylinder; η' is efficiency of the clamp hydraulic cylinder; P_test is value of test pressure inside the test pipeline fitting; P_in is the required minimum initial pressure in the clamp.

EFFECT: reduced uncompensated compression and clamping force of caps to a minimal value sufficient for providing reliable sealing socket pieces of a pipeline fitting.