Bleach, which is also referred to as Chlorox or Dixichlor, is the trade name for Sodium Hypochlorite solution (11-13%) and is a strong oxidizer. Bleach substitute is also an oxidizer .
Spraying – Following rough washing to a good Water White or better, apply dilute Bleach to 1 – 3% strength. First wet the tank surface (spray with DI water), then spray all over with Bleach, wait 30 minute (but do not allow to dry) and then rinse very well with DI water, including the tank top towards the sump. To ensure that you have covered all areas properly, this process should be carried out at least twice with good DI water.
Injection – no.
Re-circulation – Following rough washing to a good Water White standard or better, apply dilute Bleach to 1-3% strength. Mix sufficient Bleach with fresh water in the tank and heat this mixture to 40 – 50 0 C, circulate through the drop line if fitted and than circulate through butterworth machine for 3 hours. After re-circulation immediately warm butterworth to (500 C) the tank for 3 hours at maximum pressure, increase the water temperature to 80-85 o C after 45 minutes. Check (by smell) that there is no Bleach remaining, then fresh water rinse and dry.
** When there are a number of tanks requiring re-circulation, it may be significantly more efficient to make up a large batch or number of batches that can be transferred on between tanks as required.
* Use a strainer at the pump stack when circulating any solution.
Tank Lining – Stainless / Zinc / Epoxy / Phenolic (Extreme care must be taken if product other than bleach substitute is to be used in any coated space).
**These products become more aggressive with temperature increase, and should not be allowed to dry on tank walls or stored in cargo tanks as cleaning solution or slops.
Bleach will –
Improve permanganate time.