NIRE-170-1-6
22
When using polypropylene air diffuser/manifold, consider piping
material and regulate the load to the flange connection points less
than 20 kg per flange, in order to avoid distortion, leakage or
breakage of the plastic air diffuser/manifold. If the load is higher
than the limit above shown, put some supports on the piping to
reduce the load.
(2) Piping to the manifold
Fig.IV-10 and Fig.IV-11 illustrate two approaches to piping the filtrated water from the
Membrane Tank. Fig.IV-10 shows downward piping and Fig.IV-11 shows upward piping.
The downward piping is incorporated when sufficient suction can be developed via siphon
(filtrate discharge lower then tank level). The upward piping is for operation when a suction
pump is required (pump is above the membrane tank).
In both upward and downward piping, the chemical injection valve and the air discharge
valve should be installed on a pipe tee between the pipe from the filtrate water manifold to
the filtrate water control valve. These devices are necessary for chemical cleaning and are
detailed in sections VIII-3 to VIII-6.
It is
advised that you prepare and attach “riser pipe” to connect two filtrate manifolds
of one element block for ease of piping and handling
(out of Toray’s scope of supply).
Fig.IV-12 shows example of the riser pipe.
It is also advised to confirm that diameter of filtrate piping is suitable for the assumable
maximum flow velocity at each point, especially after aggregating filtrate flow from several
manifolds such as header pipes.
Fig.IV-10 Downward Piping from Membrane Tank
CAUTION
!
Filtrated water outlet
Filtrated water valve
Chemical feed line
Air discharge valve
Chemical
injection valve
