of the inlet pipe 20 and increases production efficiency in addition the internal pipe 213 includes overall strength of the inlet pipe 20 and reduces the use of metallic material also the water or fluid flowing in the pipe will not come in contact with the external threaded pipe 21 which is of metallic material this prevents water or fluid to include metallic elements such as lead zinc copper arsenic etc which reduces water quality also as depicted in fig7 and fig8 the water entry ring base 218 may be disposed at an off centered position and include a stopping ring 2181 at its distal end the stopping ring 2181 is protruding and has a smaller diameter than that of the water entry ring base 218 according to fig9 another embodiment of the invention is also described please also consult fig1 the external threaded pipe 21 includes an inner surface and a ring groove 2112 is disposed at the inner surface near the opening end of the external threaded pipe 21 the ring groove 2112 and an inner wall 212 of the external threaded pipe 21 form a strengthening band 2133 u2032 to further assist the strength of an internal pipe 213 u2032 in one embodiment the strengthening band 2133 u2032 may be a set of three or more for example the description below is based on the strengthening band 2133 u2032 in a set of three the internal pipe 213 u2032 includes a protruding ring 2132 u2032 that corresponds to or matches with the ring groove 2112 the protruding ring 2132 u2032 is locked or hooked within the ring groove 2112 in order to strengthen pulling or pushing forces exerted on the internal pipe 213 u2032 the slit 2111 u2032 of the internal pipe 213 u2032 is set to.