MP Filter LDD Series
The MP Filter LDD Series is a low- and medium-pressure duplex filter designed to ensure maximum operational continuity. It allows filter element replacement without system shutdown, making it essential for critical applications where interruptions lead to safety risks or high costs. It supports maximum pressures of 60 bar and flow rates up to 360 l/min. Equipped with DIN 24550-compliant elements and an integrated balancing valve, it ensures excellent protection and reliability of hydraulic components.
The duplex filters of the MP Filter LDD Series represent an advanced technical solution for low- and medium-pressure hydraulic applications. Their distinctive design feature is the integrated changeover function, specifically developed to allow filter element replacement without the need to stop or interrupt system operation. This hot maintenance procedure is safely facilitated by a balancing valve carefully integrated into the changeover lever, whose function is to equalize the pressure inside the filter body before performing the operational switch. From a fluid dynamics perspective, the flow passes through the filter element from the outside to the inside (from OUT to IN), optimizing contaminant retention and overall efficiency. Alongside the LDD series, the technical documentation also describes the LDP series, consisting of highly versatile in-line filters used for power transmission, protection of sensitive hydraulic components in low-pressure circuits, and coolant filtration in machine tools. Both filter types are directly and securely connected to system lines using standardized hydraulic fittings.
From a construction standpoint, the MP Filter LDD Series uses high-quality materials to ensure outstanding structural strength and wear resistance. The filter head is made of aluminum, while the external container (bowl) is manufactured from steel with cataphoretic coating to provide superior protection against external agents. Pressure resistance performance is rigorous: the maximum allowable working pressure reaches 6 MPa (60 bar), validated through strict testing that certifies a test pressure of 9 MPa (90 bar) and a minimum burst pressure of 18 MPa (180 bar). Long-term mechanical reliability is further confirmed through pulsating pressure fatigue tests successfully completed for 1,000,000 cycles within a stress range from 0 to 60 bar. The filters handle a maximum volumetric flow rate of up to 360 l/min. Connection options for the LDD configuration include female threaded fittings up to 1 1/2″ and flanged fittings up to 1 1/2″. Specifically designed for vertical installation, the filter housings are equipped with strategically positioned vent ports to prevent trapped air from circulating within the system, as well as drain ports to facilitate fluid removal before scheduled maintenance operations.
The core of the filtration system consists of filter elements engineered in strict compliance with DIN 24550 technical standards. To meet the most demanding hydraulic fluid cleanliness standards, a wide range of filter media is available: inorganic microfiber for fine filtration (with filtration ratings from 3 to 25 µm), durable wire mesh (from 25 to 90 µm), resin-impregnated paper (10 and 25 µm), and dedicated absorbent elements designed for removing free water from the fluid. To protect the filter element from extreme differential overpressure that could compromise its integrity, the filters include a bypass valve with an opening pressure calibrated at 0.35 MPa (3.5 bar) with a tolerance of ±10%. Continuous monitoring of filtration efficiency is ensured through native compatibility with visual, electrical, and electronic differential clogging indicators. The sealing system includes standard NBR seals (identified as series A), with the option of FPM seals (series V) for applications involving specific fluids.
The technical implementation of duplex filters from the MP Filter LDD Series is considered essential, if not imperative, in all critical systems where shutdown operations would result in unacceptable operating costs or, more critically, could trigger safety-related issues. At the same time, LDP versions are ideally used in pressure lines for industrial equipment or low-pressure mobile machinery, as well as for off-line filtration dedicated to small tanks. The entire range is designed and validated to operate flawlessly within an extended temperature range from -25°C to +110°C, ensuring maximum versatility across numerous industrial environments and operating conditions.
| Feature | Value |
|---|---|
| Maximum Working Pressure | Up to 6 MPa (60 bar) |
| Maximum Flow Rate | Up to 360 l/min |
| Filter Element Compliance | DIN 24550 |
| Operating Temperature | From -25°C to +110°C |
| Head Material | Aluminum |
| Container (Bowl) Material | Cataphoretic-coated steel |
| Bypass Valve | Opening at 0.35 MPa (3.5 bar) ±10% |
| Seals | Standard NBR (series A), Optional FPM (series V) |
| Hydraulic Connections LDD | Female up to 1 1/2″, Flanged up to 1 1/2″ |