Product Information
A high-pressure dosing system is designed to inject chemicals precisely into high-pressure lines or vessels. Its core component is a high-pressure plunger metering pump, which overcomes line backpressure and pushes the chemical steadily into the process. A high-pressure chemical injection unit usually comes with a safety valve, a back-pressure valve, and a buffer tank to keep pressure swings from affecting dosing accuracy. These systems are widely used in boilers, oilfields, and chemical plants where high-pressure injection is required—materials and seals have to hold up to both high pressure and corrosion.
Get a QuoteHigh-Pressure Dosing System | High-Pressure Plunger Metering Pump | High-Pressure Chemical Injection Unit
Working Principle
The chemical first enters the pump's suction chamber. The plunger moves back and forth under motor drive to draw in the liquid and pressurize it. The outlet pressure of the high-pressure plunger metering pump is higher than the injection point pressure, so the chemical is pushed into the line through a check valve. Flow rate is adjusted by changing the plunger stroke or motor speed. The high-pressure chemical injection unit has a safety valve that relieves pressure automatically to protect the piping if it gets too high. A back-pressure valve keeps the outlet pressure steady and prevents backflow. The injection runs either continuously or in pulses, controlled by a system set to the required parameters.
Application Fields
1.Boiler feedwater: injecting oxygen scavengers and scale inhibitors into high-pressure boiler systems to prevent scaling and corrosion.
2.Oilfield water injection: injecting corrosion and scale inhibitors into high-pressure injection lines to protect pipes and equipment.
3.Chemical reactions: injecting catalysts or reactants into high-pressure reactors with precise ratio control.
4.RO systems: injecting scale inhibitors downstream of the high-pressure pump to prevent membrane scaling.
FAQ
Q1: How much pressure can a high-pressure plunger metering pump handle?
A: Common industrial models reach 10–20 MPa, and some special high-pressure models go above 40 MPa. Sizing depends on the actual backpressure at the injection point—the pump's rated pressure must exceed the system's maximum pressure, with 10%–20% margin. Higher pressure means tougher requirements for seals and pump head materials.
Q2: How does a high-pressure chemical injection unit prevent backflow?
A: A check valve at the pump outlet prevents high-pressure media from flowing back when the pump stops. The system also includes a back-pressure valve to hold outlet line pressure steady, so even if the pressure at the injection point fluctuates, the pump's flow accuracy isn't affected. For highly corrosive media, the check valve and back-pressure valve should be made of corrosion-resistant alloys or ceramic.
Q3: What can be done if the dosing rate fluctuates a lot?
A: If backpressure swings are causing unstable dosing, add a buffer tank or pulsation dampener at the outlet to absorb the pressure fluctuations. Also check the plunger and seals for wear—worn parts cause internal leakage and lower flow. For applications with very tight flow tolerances, add a flow meter and closed-loop control to adjust the pump stroke in real time.