MP Filter FHD Series

Description

The MP Filter FHD Series represents an advanced solution for high-pressure hydraulic filtration. It is a duplex filter equipped with an integrated changeover function. This mechanism is essential because it allows the replacement of the filter element without requiring shutdown or stoppage of the hydraulic system. Its common applications are found in systems where operational interruptions would result in high management costs or potential safety issues. The filters are connected directly to the system lines through hydraulic fittings and are designed exclusively for vertical mounting.

Design Features and Materials

The materials used ensure robustness and resistance in demanding industrial environments. The head is made of phosphated cast iron, while the filter body is made of phosphated steel. The internal bypass valve is also made of steel. The design includes vent valves to prevent trapped air from entering the system and drain ports to facilitate fluid removal before maintenance operations. For models FHD051, FHD326, and FHD333, a balancing valve is also available, allowing pressure equalization inside the filter body before changeover.

Hydraulic Performance and Pressures

The series is designed to operate with a maximum working pressure of up to 35 MPa (350 bar) and can handle volumetric flow rates up to 345 l/min, depending on the selected size and connections.

• Test pressure: 52.5 MPa (525 bar).
• Minimum burst pressure: 105 MPa (1050 bar).
• Fatigue resistance: Tested for 1,000,000 cycles with pressure variations from 0 to 35 MPa (350 bar).
• Bypass valve: Opening pressure calibrated at 0.6 MPa (6 bar) with a tolerance of 10%.

Filter Element Specifications

The MP Filter FHD Series is compatible with different types of filter elements to meet specific fluid cleanliness requirements.

• Low-collapse element (“N”): Used with filters equipped with M25 wire mesh.
• High-collapse element (“H”): Intended for configurations without a bypass valve.
• Elements with external support (“R” and “S”): Protect the element from back pressure generated by the check valve or reverse flows, available respectively in low- and high-collapse versions.

The filter media include inorganic microfiber (with filtration ratings from 3 µm to 25 µm) and 25 µm wire mesh. Flow through the filter element always occurs from the outside to the inside (from OUT to IN).

Fluid Compatibility and Connections

Standard seals are made of NBR (series A), with the option to request optional FPM seals (series V) for specific applications. The permitted operating temperature range extends from -25 °C to +110 °C. The series includes the main models FHD 021, FHD 051, FHD 326, and FHD 333, which can be equipped with visual, electrical, or electronic clogging indicators for constant monitoring of the clogging level. Available connections include female threaded options (up to 1 1/4″) and flanged options (up to 1 1/2″), with an in-line 90° inlet/outlet configuration. The models differ in size and capacity: the FHD 021 series, for example, has weights up to 9.9 kg, while larger variants such as the FHD 333 model reach housing volumes of up to 3.35 dm³ and weights of up to 98.0 kg.

Technical summary table of the main features of the MP Filter FHD Series.