Equipment and Material Requirements for Chlorine (Cl₂) Disinfection and Sulfur Dioxide (SO₂) Dechlorination Systems

1. (a) All equipment and material used in a disinfection and dechlorination system must meet the manufacturer's recommendations.

2. (b) Storage Orientation.

   1. (1) One-ton cylinders must be stored horizontally on trunnions.
   2. (2) A 150-pound cylinder must be stored vertically and secured by a clamp or chain.
3. (c) Measurements. A Chlorine (Cl₂) and Sulfur Dioxide (SO₂) system must have a scale for determining the amount of chemical used daily and the amount of chemical remaining in a container.

4. (d) Pressure Pipe Systems for Gas Transport.

   1. (1) Gas transport pressure pipe and fittings must be at least equivalent to Schedule 80 black seamless steel pipe and 2,000 pound forged steel fittings.
   2. (2) The use of polyvinyl chloride (PVC) in a pressure pipe system is prohibited.
   3. (3) A one-ton cylinder system must use a gas filter upstream of a pressure-reducing valve.

   4. (4) A pressure pipe system must have a pressure-reducing valve if:

      1. (A) the system has a length of supply pipes greater than 20 feet;
      2. (B) an SO₂ system has a heating blanket; or,
      3. (C) there are pressure pipes on the discharge side of an evaporator.
   5. (5) A pressure pipe at the gas discharge side of an evaporator must have a rupture disk and a high-pressure alarm that warns facility staff of disk rupture.
   6. (6) A gas pipe entering a chlorinator or sulfonator must have a heated leg drop sediment trap.
   7. (7) An SO₂ system must have at least the equivalent of 316 stainless steel seat and stem.
   8. (8) A Cl₂ system must have at least the equivalent of a Monel seat and stem.

5. (e) Pressure Pipe Systems - Liquid Transport.

   1. (1) The use of PVC in a pressure pipe system is prohibited.
   2. (2) The manifolding of one-ton containers for simultaneous liquid chemical withdrawal is prohibited.
   3. (3) A liquid pipe system must include a rupture disk, a pressure switch to warn facility staff of disk rupture, and an expansion chamber.

6. (f) Vacuum pipes.

   1. (1) Vacuum pipes and fittings downstream of a vacuum regulator must be the equivalent of PVC or 316 stainless steel.
   2. (2) A vacuum pipe must have socket joints.
7. (g) Diffusers. The report must include calculations that verify a minimum velocity of 10 feet per second through any Cl₂ or SO₂ system diffuser, unless a diffuser has a mechanical mixer.

Source Note:The provisions of this §217.279 adopted to be effective August 28, 2008, 33 TexReg 6843.