... of water pipes2.Copper oxide, black nickel, black chrome, black zinc, copper and other solar selective absorbing black paint, by vacuum deposition, sputtering, electrochemical ... of 0.05Pa vacuum laminated to reduce the air caused by convection and conduction heat losses, this is similar in ... of domestic solar water heater vacuum tube solar diameter divided by 37,47,58,70 mm.According to length into ...