Measuring parameters - Tong torque

In the DEL-150 system there is a tong torque (hereinafter "tong torque"). Different inline and attachable sensors are used to measure the tong torque. The “tong torque” parameter is different from the “tong load ”ones.

 Three sensors with the “tong torque” parameter can be connected to the DEL-150 system simultaneously as several pipe spinners can be used in the rig.

Torque is a vector quantity that is equal to the product of radius-vector drawn from the axis of rotation to the point of application of force and the vector of this force. It’s characterized by rotative force action on the solid body. In physics force moment is like rotation force.

Torque has a product of force and distance. In the system Si torque is measured in newton-meters. 1 M is the lever length and 1H is force applied to the lever end perpendicularly.

So “tong torque” is the product of force F and the arm of force h: M(F)=F∙h. 

The arm of force h is the crosscut from the point or axis to the place of force. For instance, force is 7kN applied on the distance of 35 sm. from the point gives torque M=7×0,35=2,45 кNm.

Hydraulic tong torque is determined by pressure. It’s necessary to take the position of gearshift lever into account for hydraulic tongs with twin-drives where direct measurement of torque by load sensors is impossible. “Hydraulic tong torque” parameter is used together with pressure transducer TP-140 (D) and the inductive sensor. The inductive sensor controls the position of gearshift lever. 

If you use the pressure transducer for measured pressure recalculation without regard to the position of gearshift lever, it displays the incorrect torque readings.