1. The groove and hole shall be carefully inspected for one week, and there shall be no residual burr, damage or crack appearance, and the dirt near the pipe orifice shall be eradicated.

2. Apply lubricant near the rubber sealing ring, and then install it on both ends of the steel pipe by hand. Make sure that the tension near the rubber sealing ring is basically the same.

3. Two pieces of grooved pipe fittings and two sides of bolts shall be tightened symmetrically to make the gap between each piece of groove equal. When it is close to tightening but not too close to the rubber sealing ring, turn the grooved pipe fittings with both hands to make all the pipe fittings and the sealing ring contact evenly. At this time, investigate whether all the pieces of grooved pipe fittings have entered the groove. After entering the groove, tighten the bolts symmetrically. If the sealing ring is wrinkled during tightening, replace it.