Top 5 High Viscosity Pump Questions & Answers Before You Buy

Understand How to Select, Size, and Operate Your Piston Pump With Confidence

Choosing the right high viscosity pump takes more than picking a pressure rating. Material properties, application type, and system design all affect how your pump performs day to day. Below are the five questions we hear most often from sealant and adhesive manufacturers and end-users — answered clearly and practically.

Not every pump can move thick, slow-flowing materials reliably. Sealants, structural adhesives, mastics, and dense greases demand a pump built for the job.

Our air-operated piston pumps use positive displacement. They deliver a fixed volume per cycle, regardless of how thick the material is. That means consistent output — even when viscosity changes during production.

Here's what to look for in a pump for high viscosity applications:

• Large inlet ports to allow thick material to enter the pump without starving or cavitating
• Mechanical check valves that seal fully between strokes — our Chop-Check design excels here
• Ceramic-coated plunger rods and cylinder tubes that resist wear when handling abrasive, filled materials
• High pressure ratios to push material through long lines or dense application systems

Our piston pumps handle materials from light coatings all the way up to silicone sealants and structural mastics exceeding 1,000,000 cPs.

We offer piston pumps with pressure ratios from 5:1 to 65:1.  Our team can help you calculate the right ratio based on your material and system layout.

Often, yes. But it depends on how precise your dispensing needs to be and what flow rates you require.

For bulk transfer — moving material from a drum to a supply tank or circulation loop — flow rate is the main priority. For point-of-use dispensing — applying adhesive or sealant at a workstation or robot — consistent, controlled output matters more than volume.

Some production lines use two pumps:

• A higher-flow pump for drum-to-system transfer

• A lower-flow, higher-precision pump for metered dispensing or extrusion

Not sure which setup fits your line? Use our Piston Pump Product Selector to get a tailored recommendation in just a few steps.

Downtime on an adhesive or sealant line is expensive. The good news is that most causes are predictable — and preventable.

Common causes and practical fixes:

• Dry running — install a low-level cutoff to stop the pump automatically before the drum empties
• Seal and packing wear — our pumps feature adjustable packing with a wave spring design; inspect and adjust on a scheduled basis before leaks develop
• Material hardening in lines — flush lines during planned stops; consider heated hose options for temperature-sensitive materials
• Running the pump too fast — size your pump to operate at 60–70% of maximum rated output; this reduces wear and extends component life significantly
• Slow maintenance response — keep a service kit on hand; our kits include all required parts for a complete repair, so you're not waiting on components

The right accessories also make a real difference. Follower plates improve material feed from drums. Pressure regulators stabilize output. Low-level cutoff controls protect your pump and your process.

Start With the Right System

Accessories are a core part of any reliable pump setup. We offer complete piston pump packages for sealant and adhesive applications that include the accessories your process needs — follower plates, pressure regulators, low-level cutoff controls, dispense valves, and material hoses — all matched and ready to install.

For more complex or non-standard requirements, our Solutions Center in Mooresville, NC can configure and build a custom system around your specific process, materials, and timeline.