Suction Filters — Pump Inlet Protection & Cavitation Prevention
Hydraulic suction filters trap and remove large impurities from the fluid before it reaches the pump. For effective pump protection, install them directly in the pump suction line, below the minimum fluid level of the reservoir.
New equipment and system start-ups often introduce solid particles (metal flakes, rust, debris) into the fluid. Suction strainers act as the first-line safety filter, preventing these large particles from damaging pumps and downstream components and extending the life of finer filters.
Why Proper Sizing Matters
Suction filters must be correctly sized to avoid pump cavitation. Always select a suction line filter element that matches the pump flow and NPSH requirements — the wrong element will starve the pump and cause failures.
Key Functions of a Suction Filter
- Prevents large solids from entering the hydraulic circuit
- Extends downstream filter life and service intervals
- Reduces maintenance downtime and protects critical components
- Avoids damage to fine filters from large particles such as iron filings and rust
Suction Filters — Specifications
- Inline or tank-mounted options
- Flow rates up to 1000 l/min (model dependent)
- Operating temperature: -20 °C to +100 °C
- Recommended for mineral oil-based hydraulic fluids
- Connection variants: BSP (ISO 228) or NPT (ANSI B1.20.1) from 3/8” to 3”
- Optional magnetic bars for ferrous particle capture
- Integrated bypass valve (≈0.2 bar / 3 PSI) to reduce pressure drop risks
Suction Strainers / Submerged Elements
Submerged pump suction filter elements sit on the pump suction line inside the tank. Typically made from wire mesh (common: 125 & 149 µm), they protect the pump inlet and can be supplied in finer meshes (50/63/74/100 µm) or with a magnetic column on request.
Variants can include bypass valves and magnetic inserts — specify mesh and accessories based on expected contamination and maintenance intervals.
Spin-On Suction Filters
Spin-On types feature an aluminium head and one or two replaceable spin-on elements. Available for inline or flange mounting (inline preferred), they offer quick servicing and fast element replacement — suitable up to ~150 l/min for many mobile and industrial apps.
External Suction Filter Assemblies
For small tanks or pumps installed away from the reservoir, external inline or tank-wall mounted assemblies work well (typical flows 500–700 l/min). These can include clogging indicators and service-friendly housings.
How we help
Our engineers will recommend the best-suited suction line filter element, clogging indicators, and accessories to match your contamination profile and uptime targets because guessing is for amateurs.