Modifying Service Conditions in Rubber-lined Vessels
Frequently we receive inquiries regarding the practice of switching chemical services in rubber-lined vessels. The reasons vary and need not be discussed here. The following statements are offered to prevent problems which may be encountered with such practices.
Switching service conditions in a rubber-lined vessel will most probably shorten the service life of the rubber lining.
Please consider the following statements regarding this practice:
- Salt solutions of nearly neutral pH are probably the least likely to cause problems. Even with this, thorough rinsing is absolutely necessary to prevent cross-contamination or possibly an unexpected reaction.
- Switching from acids to caustics and vice versa will require both rinsing and neutralization between changes. If this is not done, it is possible to create serious exothermic conditions where the two pH extremes meet. This will cause local degradation and deterioration of the lining.
- Never should one consider switching services in a vessel lined with soft gum natural rubber (PG70) intended for concentrated hydrochloric acid service; even to more dilute versions. Depending on comparative concentrations, this will result in either swelling or shrinking of the lining and most likely localized seam failure initially followed by a general failure.
It is recommended to contact the manufacturers of all service liquids involved for the most effective and efficient techniques for neutralizing them before switching services.
Please Contact Blair Rubber to verify that an existing lining will be compatible with any new service conditions.