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Should You Flush and Clean Your Pump?
Apr 13, 2026
Yes, most pumps should be flushed and cleaned on a schedule that matches your process. In many applications, flushing is the easiest way to prevent cross-contamination, hardened residue, check-valve sticking, and compatibility-driven failures that show up as repeated downtime.
Contributors
This blog was developed using insights from PSG® subject matter experts with extensive experience in troubleshooting pump failures and designing reliable pumping systems across industrial, chemical, terminal and marine environments.
Flushing and cleaning is not just “good housekeeping.” In real systems, residue becomes a mechanical problem. Product that dries, hardens, crystallizes, or builds up in pockets can cause stuck check valves, loss of prime, reduced flow, and premature wear. Even when the pump still runs, residue can contaminate the next batch or trigger compatibility issues when cleaning fluids interact with leftover process fluid.
When Flushing and Cleaning Is Non-Negotiable
In these scenarios, flushing is not optional, it’s part of process control and reliability:
• Hygienic or sanitation-sensitive processes (food, beverage, dairy, biopharma-adjacent): residue retention can create contamination risk.
• Paints, coatings, adhesives, resins or other fluids that can harden when they sit: dried material can rupture diaphragms or damage internal components.
• Frequent product changeovers: flushing minimizes cross-contamination and reduces scrap.
• Any fluid that leaves solids behind (slurries, pigments, fillers) or crystallizes on shutdown.
• Any chemical service where the cleaning fluid might react with the process fluid: you must control what remains in the wet end.
When Flushing Might Be “Nice to Have” Instead of Mandatory
If you pump a stable, non-curing, non-hygienic, non-solidifying fluid in a dedicated line with no product changeovers, flushing may be less frequent. However, even in these systems, a basic flush before extended shutdown can prevent residue build-up and simplify the next startup.
What Happens If You Don’t Flush (Common Failure Modes)
Skipping cleaning often shows up later as one of these “mystery” problems:
• Check valves stick open or closed (debris, dried residue, or swollen elastomers).
• Loss of prime or erratic flow because residue prevents full valve seating.
• External leaks as gaskets and elastomers degrade or clamp loads change after repeated buildup.
• Premature diaphragm/seal wear because residue creates abrasion and heat.
• Cross-contamination between batches or product changeovers.
• Accelerated compatibility failures when cleaners react with leftover product.
Residue buildup and chemical deposits take a gradual toll on seals, diaphragms, and valve seats, often compromising their function long before they visibly fail. When flushing reveals worn or degraded components, replacing them with genuine parts ensures the correct material compatibility and dimensional accuracy your pump needs to perform after cleaning. Using non-original replacements risks reintroducing the same vulnerability you're trying to correct. Find the right components for your pump on our genuine parts page.
Step-by-Step: A Practical Flush and Clean Routine (AODD-Friendly)
AODD pumps are commonly used in changeover-heavy processes because they’re relatively easy to flush and maintain. A simple field routine looks like this:
Make it safe: shut off and bleed compressed air, relieve liquid pressure, and follow your facility lockout procedures.
Drain/empty the wet end: route remaining product to a compatible container for recovery or disposal.
Choose a compatible cleaning solution: it must be appropriate for the product and chemically compatible with all wetted components.
Connect a flush loop (if possible): circulate cleaning solution through the pump and hoses long enough to remove residue.
Rinse (if required): flush with clean water or a compatible rinse fluid until the discharge runs clear.
Purge the pump: remove the suction hose and run briefly (per your manufacturer guidance) to clear remaining fluid.
Inspect what comes out: residue, chunks, or discoloration are clues, adjust cleaning frequency or chemistry if needed.
If residue remains: disassemble and clean-out-of-place (COP) before returning to service.
Manufacturer documents also reference similar steps. For example, All-Flo™ IOM guidance describes circulating a cleaning solution and then flushing with clean water in its sanitary/hygienic pump manual (PDF). Wilden® EOM documents also caution to thoroughly flush pumps before installing into process lines and to clean/sanitize food-grade pumps before use in clamped metal pump documentation (PDF).
Choose the Cleaning Fluid Carefully (Compatibility Applies to Cleaners Too)
A common mistake is selecting a pump for the process chemical, then damaging it with the cleaning chemical. Cleaning fluids must also be compatible with the pump’s wetted materials. Before you flush, verify compatibility for housing/manifolds, diaphragms, balls/seats and O-rings. If you suspect compatibility is already causing failures, this diagnostic article can help: 5 Signs Chemical Compatibility Is Slowly Destroying Your Pump.
Also consider temperature. Hot cleaning cycles can change compatibility outcomes and accelerate elastomer swelling or softening. If your process uses hot washdown or CIP, the cleaning temperature should be part of the compatibility decision.
CIP vs. COP: Cleaning Strategy Often Drives Pump Selection
In hygienic environments, cleanability is often designed in. Wilden® notes that Saniflo™ Hygienic Series (HS) pumps feature a free-draining flow path designed to support clean-in-place (CIP) capability and reduce trap zones on the HS hygienic pump page. For standard food-grade transfer where full CIP and HS design are not required, Wilden also offers Saniflo™ FDA Series pumps.
If your operation requires CIP, prioritize designs that drain and clean effectively without disassembly. If COP is acceptable, prioritize fast disassembly and easy access to check valves and diaphragms.
Industry Examples: Where Flushing Solves Real Problems
Paints and coatings: changeovers and drying/curing residues are common, so flushing is a practical reliability habit. AODD pumps can be cleaned and flushed quickly during product changeovers to reduce contamination risk.
Hygienic processes: flushing and cleaning protects batch integrity and helps prevent bacteria buildup. In these environments, a pump that is easy to drain and flush can be a major operational advantage.
Chemical transfer: flushing prevents unintended chemical mixing inside the pump. Even small amounts of leftover product can react with the next fluid or with a cleaner, creating heat, gas or residue.
A Simple Rule for Setting Your Cleaning Frequency
If you’re not sure how often to clean, use the most conservative driver in your process:
• After every batch or product changeover (best for quality control).
• Before extended shutdowns (prevents residue hardening/crystallizing).
• When the fluid is prone to curing, setting, or drying (flush immediately after use).
• When contamination risk is high (hygienic service).
• When you see performance drift (flow loss, sticking valves, harder priming).
Next Steps: Parts, Help, and Faster Cleaning Turnarounds
If flushing reveals worn diaphragms, check valves or seals, keeping the right repair kits on hand can minimize downtime. Browse genuine repair parts and rebuild kits on the PSG® Store, or contact us for help identifying the correct kit for your pump model.
For additional information, please review our returns policy, shipping policy and terms and conditions, including our terms of use.
Contributors
Piyush Kapoor
Piyush Kapoor is a rotating equipment specialist focused on reliability and material selection. His work includes evaluating how cleaning chemistry and operating temperature affect wetted materials, especially elastomers and plastics, over long service intervals.
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