Why Hengsheng perfer to Push Bending ,not only bending machine for Elbow

HENGSHENG is a professional copper fittings manufacturer.And we concern the workmanship very much. HENGSHENG's Workmanship is much different from other competitor . 
Take our Elbow workmanship for examples;  
Most of our competitor used bending machine to bend the elbow. We found the thickness of the elbow will be 20% thiner than the tube thickness they used .The thickness reduced when used the bending machines. This is the key weekpoint for this wormanship. HENGSHENG also realized this quality problem. After two year's study and machinery improvement.We have found a better workmanship to avoid the bending machines's problem .We named it Push bending workmanship . 
Breif introduction of the new workmanship : 
We insert one tube into the elbow 's mould ,then push in one size to make the tube walk forward along with the elbow's mould .Because we only push in one size and enforce the tube walk forward .So the thickness will be thicken .