Drain cocks must be provided at all low points and wherever required to ensure that
every section of the pipe work can be drained. If not indicated the sizes of the screwed
joint, for galvanized steel pipe, shall be malleable cast iron screwed pipe fitting
according to Thai Industry Standard 249-1977. The joint shall be made with an
approved compound carefully and smoothly applied on the male thread only. Lamp
wick, oakum or any similar materials shall not be used in making screw joint. Graphite
or anti-seize compound shall be used on clean-out plug. threads shall be perfect and
clean cut, and exactly threaded and screwed up tight into fittings without reducing
waterway.