What are special pumps and glands used for corrosive fluids?

When dealing with corrosive fluids, it's essential to use specialized pumps and sealing systems to ensure the safe and efficient transfer of these fluids. Corrosive fluids can damage standard pump components and gland seals, leading to leaks, reduced efficiency, and safety concerns. Here are some specialized pumps and gland types commonly used for handling corrosive fluids:

Specialized Pumps:

Diaphragm Pumps:

How They Work: Diaphragm pumps use a flexible diaphragm to create suction and discharge fluid. The diaphragm isolates the fluid from the moving parts of the pump.

Application: Diaphragm pumps are suitable for corrosive fluids because the diaphragm material can be selected based on the chemical compatibility with the fluid being pumped.

Mag-Drive or Magnetic Drive Pumps:

How They Work: Mag-drive pumps use magnetic coupling to transfer torque from the motor to the impeller, eliminating the need for a shaft seal. This design prevents leaks.

Application: Mag-drive pumps are often used for handling corrosive fluids as the sealed design minimizes the risk of fluid leakage.

Peristaltic Pumps:

How They Work: Peristaltic pumps use a flexible tube and a rotor to create a squeezing action, moving the fluid through the tube without direct contact with pump components.

Application: Suitable for corrosive fluids since the fluid only comes into contact with the tubing, which can be selected for chemical compatibility.

Canned Motor Pumps:

How They Work: Canned motor pumps have a hermetically sealed motor and pump in a single unit, eliminating the need for a mechanical seal.

Application: Commonly used for handling corrosive and toxic fluids as the sealed design prevents leakage.

Specialized Gland Seals:

Mechanical Seals with Corrosion-Resistant Materials:

Features: Mechanical seals, when used, should be made from materials resistant to corrosion. Components such as seal faces, springs, and elastomers may be selected based on the specific corrosive nature of the fluid.

Teflon or PTFE Gland Packing:

Features: Gland packing made from Teflon (polytetrafluoroethylene or PTFE) is resistant to a wide range of corrosive chemicals.

Application: Suitable for pumps handling corrosive fluids, especially when traditional mechanical seals are not practical.

Graphite Gland Packing:

Features: Graphite-based gland packing is often resistant to corrosion and can withstand high temperatures.

Application: Used in pumps handling corrosive fluids that may also have elevated temperatures.

Bellows Seals:

Features: Bellows seals provide a flexible and corrosion-resistant barrier between the pump shaft and the fluid.

Application: Commonly used for corrosive fluids, especially when the pump operates in a challenging environment.

When selecting pumps and gland seals for corrosive fluids, it's crucial to consider the specific characteristics of the fluid, including its chemical composition, temperature, and any abrasive properties. Consulting with pump manufacturers or specialists in fluid handling systems is advisable to ensure the right equipment is chosen for the application. Additionally, regular maintenance and monitoring are essential to ensure the continued integrity and efficiency of the pumping system.