If the homogenizing valve is where particle size reduction happens, the cylinder block and compression block are what make it possible. These precision-engineered components form the pressure chamber where your product is compressed from atmospheric pressure to hundreds — sometimes over a thousand — bar before being forced through the homogenizing valve.
At BOS Homogenisers, we have worked with cylinder blocks and compression blocks from every major homogenizer manufacturer for decades.
Understanding the Cylinder Block
The cylinder block (also called the pump block or liquid end block) is the central body of the homogenizer’s pump section. It houses the plunger bores, contains the suction and discharge passages, and provides mounting surfaces for valve assemblies, seal housings, and other pump-end components.
The working principle page explains how these components work together.
Understanding the Compression Block
The compression block sits between the cylinder block’s discharge side and the homogenizing valve assembly, channeling high-pressure product into a single stream directed at the homogenizing valve gap.
Materials and Construction
Forged Stainless Steel
The most common material for modern homogenizer cylinder blocks is forged stainless steel, typically AISI 316L. High fatigue strength, excellent corrosion resistance, good machinability.
Duplex Stainless Steel
For ultra-high pressure (above 600 bar), corrosive products, or extended service intervals, duplex stainless steels offer enhanced strength and corrosion resistance.
Cast Stainless Steel
Older homogenizer models often used cast stainless steel cylinder blocks, requiring more frequent inspection.
Inspection: What to Look For
Visual Inspection
Check bore surface condition, seal housing surfaces, product passages, external surfaces, and mounting surfaces.
Dimensional Inspection
Measure bore diameter, bore straightness, and seal housing dimensions at scheduled intervals.
Non-Destructive Testing
Dye penetrant testing, ultrasonic testing, and pressure testing for critical applications.
Reconditioning vs. Replacement
Reconditioning (re-boring, honing, re-machining seal housings) is cost-effective when bore wear is uniform and within limits. Replacement is necessary when cracking is detected or bore wear exceeds maximum allowable oversize.
BOS Homogenisers: Your Partner
We supply new and reconditioned cylinder blocks for APV, Gaulin, GEA Niro Soavi, SPX. Explore machines we support and spare parts catalogue.
Concerned about your cylinder block? Contact us for an expert assessment.