The BIJUR DELIMON DD series is a hydraulically-operated dual-line metering valve for centralized lubrication systems in industrial machinery. Each valve body houses a pilot piston and main piston that cycle in response to alternating lubricant pressure from the dual-line supply, dispensing a precise, individually adjustable volume of oil or grease (up to NLGI #2) to bearing points. The valve operates without springs or electrical components — lubricant pressure alone drives both the metering stroke and the automatic reset on line reversal.

How does a dual-line metering valve work?

In a dual-line lubrication system, two supply lines run in parallel to all metering valves. Pressurizing one line drives the DD valve's pilot piston downward, which routes pressure to the top of the main piston — forcing it down and displacing a measured shot of lubricant from the lower chamber to the first bearing. When system pressure is reversed (the second line pressurized, the first vented), the pilot piston shifts upward, and the main piston strokes in the opposite direction, delivering lubricant from the upper chamber to the second bearing. A visual indicator pin extends and retracts with each cycle, giving operators a direct confirmation that the valve is functioning.

DD-2X vs. DD-5X — choosing the right output range

Both variants share the same 3/8" inlet and 1/4" outlet tube connections, 240 bar maximum pressure, and 163°C temperature ceiling. The DD-5X achieves its wider range through a longer adjustment screw travel of approximately 30 mm. Output is set independently per outlet — one valve can deliver different volumes to its two bearing points.

Valve block configurations and cross-porting

DD valves are assembled in blocks of 1, 2, 3, or 4 individual metering sections on a common manifold, each section serving two bearing points. A cross-porting plug option internally connects both outlets of a single valve section, combining their output volumes to serve one bearing point at roughly double the per-outlet rate. This is useful when a single bearing requires more lubricant than one outlet can supply within the available cycle time, without upsizing to the larger DD-5X variant.