hands of worker as holding plastic water pipes in device for melting, welding

assembly busy connect construction device electric engineering equipment extrusion fitter fitting fixture fusion hand handy heat heater hot industrial industry iron joint manpower manually melt pipe pipeline piping plastic plumber polypropylene power tool skilled soldering technique technology tube tubing use warm water welder welding work progress place worker workshop hands holding pipes melting plumber#39aph39#s connecting indoor site residential building