“Chemical pump” is not an official industry term, but it does have a generally agreed-upon meaning. A chemical pump should:
Resist the corrosive effects of multiple chemicals at various temperatures; and
Avoid any unintended emissions that could harm operators or the surrounding area.
That's an intentionally broad definition, because chemical pumps can be crafted from any number of materials and for numerous industries. But before applications of the equipment, let us consider how it works.
When researching chemical pumps, a company may find numerous types of pumps listed. Some of those may include powder diaphragm pumps, electro-polished pumps, eccentric screw pumps, barrel pumps, and peristaltic pumps. However, know that most chemical pumps fall into one of two categories: magnetic drive pumps and air-operated diaphragm pumps.
Magnetic drive pumps are centrifugal pumps. (That is they use a rotation motion to facilitate fluid flow.) Air-operated diaphragm pumps are positive displacement pumps (meaning that they use air suction to trap a certain amount of fluid and discharge it in a fixed amount). These chemical pumps have different advantages and disadvantages, but they share one thing in common: They do not have a shaft seal.
Shaft seals have the highest change of failure in any pump assembly. Omitting those means that a pump will run without leaking so long as operators correctly select, use, and maintain it.