FluidTech News

 How Stroke Length Adjustment Controls Metering Pump Accuracy In chemical dosing, water treatment, and industrial injection systems, a metering pump is valued for one key capability — precise flow control. Many users assume flow adjustment depends on motor speed. In reality, most metering pumps regulate flow by changing the stroke length. What Is Stroke Length in a Metering Pump? Stroke length refers to the moving distance of the diaphragm or plunger during one reciprocating cycle. The principle is straightforward: Longer stroke → larger discharge volume per cycle Shorter stroke → smaller discharge volume Constant speed → stable dosing frequency So the output flow rate is mainly controlled by adjusting how much liquid is displaced in each stroke. Mechanical Principle Behind Stroke Adjustment Inside a metering pump, rotational motion from the motor is converted into reciprocating motion through: Eccentric cam mechanism Connecting rod system Diaphragm or plunger assembly When the adj...

 Rotary Pump Volumetric Efficiency: What It Is and How to Calculate It Rotary pumps are widely used across industrial sectors — from chemical dosing to lubrication systems — because they deliver relatively steady flow and handle a range of viscosities. Yet, a question engineers frequently encounter is: Why is the actual flow lower than the expected value on paper? The answer often points to one critical performance metric: volumetric efficiency. Understanding how to calculate and interpret this efficiency can help you distinguish between equipment faults and system design limitations. What Is Volumetric Efficiency? Volumetric efficiency (ηv) describes how closely a pump’s actual performance matches its ideal theoretical delivery. In a perfect world, a rotary pump would deliver exactly the liquid volume defined by its geometry and running speed. But in reality, internal leakage, compressibility effects, and pressure losses reduce the actual output. The classic formula is: Volumetric...

 Does Isolation Sleeve Material Really Affect Magnetic Pump Efficiency? When selecting a magnetic drive pump, most engineers focus on: Flow rate Head Power Temperature rating However, one critical component is often overlooked — the isolation sleeve. In reality, the material of the isolation sleeve can directly impact: Transmission efficiency Heat generation Energy consumption Long-term operating stability Why Material Matters Magnetic pumps transmit torque through magnetic coupling: The outer magnet rotates → magnetic field transfers torque → inner magnet drives the impeller. Between them sits the isolation sleeve. Its job is to: Seal the process fluid Separate motor and liquid Allow magnetic flux to pass through Here’s the key issue: When the sleeve is made of conductive metal (such as stainless steel), rotating magnetic fields induce eddy currents. Eddy currents cause: Energy loss Additional heat generation Reduced transmission efficiency In continuous-duty applications, efficie...

 Understanding Air Lock in Self-Priming Pumps: Causes and Practical Engineering Solutions Self-priming pumps are widely used in industrial systems because they can evacuate air from the suction line and begin pumping without manual priming. However, in real-world applications, operators sometimes encounter a frustrating issue: The pump starts but fails to deliver liquid Flow rate drops unexpectedly Discharge pressure fluctuates Unusual vibration or noise appears In many cases, the pump itself is not damaged. The real cause is often air lock. What Is Air Lock in a Self-Priming Pump? A self-priming pump works by creating a vacuum in the pump casing to draw liquid upward through the suction line. For this process to function properly, a continuous liquid column must be maintained. Air lock occurs when: Air accumulates inside the pump casing The liquid column is interrupted The impeller begins circulating air instead of liquid Once this happens, the pump loses its ability to generate s...

 Why Metering Pump Inaccuracy Often Isn’t a Pump Problem Metering pumps are critical for delivering precise doses of chemicals, additives, or treatments in water treatment, chemical processing, pharmaceuticals, and many industrial systems. When a metering pump starts delivering off-target volumes, the instinctive response is often: “The pump must be bad.” But in most real-world cases, the cause is not the pump itself — it’s the system conditions surrounding the pump. Let’s break down the real reasons behind metering pump inaccuracies and how to diagnose them effectively. Product overview and specifications: 🔗 https://www.scpv.cn/jiliangbeng/ 1. Suction Issues: Air Entrainment and Leakage One of the most common causes of metering inaccuracies is air entering the suction side. Even tiny leaks at: Tube fittings Suction line connections Foot valves Pump inlet gaskets can allow air bubbles to enter the pump chamber. Since air is compressible, it drastically changes the actual delivered...

 Magnetic Pump Overheating: Three Real Engineering Cases and What They Reveal Magnetic drive pumps are widely used in chemical processing, pharmaceuticals, new energy, and environmental systems due to their leak-free design and high safety level. However, one issue occasionally reported by plant engineers is: Unexpected temperature rise during operation. In most situations, the root cause is not material failure or manufacturing defects — it is system condition mismatch. Below are three real engineering scenarios that explain the most common causes of magnetic pump overheating: Insufficient internal circulation Improper back pressure Gas locking (air/vapor entrainment) For product reference and structural overview, see: 👉 https://www.scpv.cn/cilibeng/ Case 1: Blocked Suction Filter → Insufficient Internal Cooling Background A chemical plant was transferring an organic solvent using a magnetic drive centrifugal pump. After several months of stable operation, the pump casing tempera...