(a) All equipment and material used in a disinfection
and dechlorination system must meet the manufacturer's recommendations.
(b) A 150 pound cylinder must be stored vertically
and secured by a clamp or chain to prevent it from falling over. A
one-ton cylinder must be stored horizontally on trunnions.
(c) Measurements. A gaseous chlorine and sulfur dioxide
system must have a scale designed for determining the amount of chemical
remaining in the connected cylinders.
(d) Pressure Pipe Systems for Gas Transport.
(1) Gas transport pressure pipes must be at least equivalent
to Schedule 80 black seamless steel pipe. Gas transport fittings must
be at least equivalent to 2,000 pound forged steel fittings.
(2) The use of polyvinyl chloride (PVC) in a pressure
pipe system is prohibited.
(3) A one-ton cylinder system must use a gas filter
upstream of a pressure-reducing valve.
(4) A pressure pipe system must have a pressure-reducing
valve if:
(A) the system has more than 20 linear feet of supply
pipes;
(B) the system is a gaseous sulfur dioxide system with
a heating blanket; or
(C) there are pressure pipes on the discharge side
of an evaporator.
(5) A pressure pipe on the gas discharge side of an
evaporator must have a rupture disk and a high-pressure alarm to
warn wastewater treatment facility staff of disk rupture.
(6) A gas pipe entering a chlorinator or sulfonator
must have a heated leg drop sediment trap.
(7) A gaseous sulfur dioxide system must have a seat
and stem constructed of material with corrosion resistance and brittle
strength at least equivalent to 316 stainless steel.
(8) A gaseous chlorine system must have at least the
equivalent of a Monel® seat and stem.
(e) Pressure Pipe Systems - Liquid Transport.
(1) The use of PVC in a pressure pipe system is prohibited.
(2) The manifolding of one-ton containers for simultaneous
liquid chemical withdrawal is prohibited.
(3) A liquid pipe system must include a rupture disk,
a pressure switch to warn wastewater treatment facility staff of disk
rupture, and an expansion chamber.
(f) Vacuum Pipes.
(1) Vacuum pipes and fittings downstream from a vacuum
regulator must have corrosion resistance equivalent to PVC or 316
stainless steel.
(2) A vacuum pipe must have socket joints.
(g) Diffusers. The minimum velocity through any chlorine
or sulfur dioxide system diffuser must be at least 10 feet per second.
The engineering report must include calculations that verify this
requirement is met, unless a diffuser has a mechanical mixer.
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