brass circulation pump feature: 1)used to supply water and pressure for mansions of city, villa of suburb,house. 2)low cost Brass circulation ... ) Volume(m3)GPD25-4SCast iron/brass/bronze3speed0.282206542.8252.70.004GPD25-5SCast iron/brass/bronze3speed0.42208553252.70.004GPD25-6SCast iron ... mansions of city,villa of suburb,house,to match with industrial equipment,to supply water in cycle for cooling ...