Case Study: Chemical Dosing for Boiler Water Treatment with Custom Cabinets

Case Study: Chemical Dosing for Boiler Water Treatment with Custom Cabinets

chemical dosing pump system for steel mills


Illinois Process Equipment, IPE, was asked to provide a chemical dosing system for boiler water treatment at a large steel mill. IPE is a leading Midwest supplier of fluid handling and process equipment, offering full system design, service, and quality pumps. We provide innovative solutions to fluid transfer applications and are set apart from other pump suppliers with our technical expertise and problem-solving abilities.

We created a custom-designed, chemical dosing pump system with protective fiberglass cabinets to provide the solution this steel mill needed for reliable operation in challenging steel mill conditions. 


The client was experiencing shortened boiler tube life caused by corrosion and scaling. Their water treatment company recommended adding an oxygen scavenger and scale inhibitor to the boiler feed water, which was at about 1,100 PSIG. Flow rates for the chemicals were less than 0.5 GPH. Furthermore, the customer wanted to protect the pumps and controls from the dirty environment in the mill. They also wanted the ability to inject another chemical, if needed, at a later date.

There are several challenges with operating process equipment for boiler water treatment in a steel mill. The most common challenges for reliable operation of pump process equipment in a boiler room environment include:

  • The need for accurate chemical injection at high pressure
  • The presence of caustic based chemicals
  • Poor visibility of controls due to overhead pipes and equipment
  • Excessive heat

By partnering with another innovative supplier, IPE designed highly accurate chemical dosing skids inside fiberglass protective cabinets that addressed the challenges and provided the solutions this steel mill needed.


The technical services manager at IPE partnered with Grundfos and Shelter Works, a provider of fiberglass shelters for field equipment protection, to design a high pressure chemical injection skid with a protective enclosure. Our technical team engineered and fabricated the complete chemical dosing process equipment system including two Grundfos DMH series high pressure diaphragm metering pumps with analog-capable controllers enclosed in fiberglass custom cabinets designed to protect the pump system from boiler room conditions. The skid and enclosure were amply sized to allow for the addition of a third metering pump in the future.

Accurate chemical injection at high pressure: 

Grundfos DMH pumps use hydraulically-actuated Teflon diaphragms to allow high pressure metering at low flow rates. DMH pumps have a very high dosing accuracy and allow exact reproducibility. The dosing flow fluctuation of the DMH 287 pumps supplied is < +/-1% and the linearity deviation is +/-1% of the full-scale value. The integrated AR flow controller allows for remote control using a boiler water analyzer analog signal. 

Chemical exposure:

To address the challenge of operating in an environment where caustic based chemicals and sulfite are present, IPE’s custom solution was designed to protect the pump system from direct exposure to aggressive chemicals. Most process lines are located above placement of the pump system, the fiberglass cabinets protected the pump system below.

Properties of fiberglass include resistance to chemical corrosion, making it the perfect material to house a chemical dosing system.

Poor visibility:

The next challenge facing IPE technicians was poor visibility. The overhead piping and equipment caused obstructions from overhead lighting and cast shadows that made it difficult to easily view the controls. Our goal was to make it easy for technicians to see the digital controls and calibration columns for measurement of flow rate at all times.

Each fiberglass cabinet was outfitted with a 25 watt NEMA 4X LED light and switch control providing easy visibility of all controls.

Excessive heat: 

Boiler rooms can be extremely hot which can affect some equipment performance.

A 7” shutter-mounted exhaust fan and vent with thermostat control were installed in each fiberglass cabinet to provide ventilation and maintain an operating temperature under 90°F.


This chemical dosing system at our steel mill customer’s plant provided the pumping solutions needed to overcome the environmental challenges of boiler room conditions, including caustic based chemicals, poor visibility, and excessive heat.

This project shows the ingenuity of the technical team at IPE and our dedication to provide process equipment solutions, not just equipment.



IPE’s technical expertise and problem-solving skills are what set us apart from other process equipment and pump suppliers. Contact us with any challenges in your pump process for innovative, custom process equipment solutions.