Pilot Filter
Pilot filter is used to filter the impurities in the pilot oil of hydraulic system. The pilot oil controls the operation of each valve element and hydraulic system. The pilot system can use small flow to control large flow. And also when the driver stops pushing and pulling the control lever, the pilot valve will close. So as to cut off the oil circuit, It won’t need return filter. They are sensitive components and can only see a small amount of traffic. It is easy to filter the entire system to the required level of cleanliness.
Pilot filter is a hydraulic filter in the working hydraulic system putting in the hydraulic filter housing. The location of the hydraulic pilot filter in excavator is mostly near the hydraulic pump. Generally installed under the control lever in the cab, and the assembly of the pilot filter has a screw head protruding out. Of course, some of the pilot filters of the excavator are screw mounted. Some excavators also have a smaller screen installed in the pilot control valve. The functions are:
Pilot filter will affect the flow of hydraulic oil, pilot control pressure, and then affect speed of the whole vehicle.
Protect other precision components. When you Start your equipment in the cold will provide some of the most extreme viscous flow surges your pilot control circuit will experience. It is very important that all components in your circuit are designed to withstand this pressure time and time again.
Optimize the system performance. Lower pressure drop saves energy and reduces filter bypass in cold weather conditions. Minimizing the exposure of critical and expensive components to abrasive contamination keeps downtime and maintenance costs low. The maximum dirt retention capability ensures that the filter maintains a specified service interval in the worst operating environment.
Minimize Bypass Contamination.Lower flow restriction enhances filtration performance by reducing bypass events in cold start situations. Lower Pressure Drop – Better Filtration Performance Lower pressure drop (lower flow resistance) means your pilot control circuit is less likely to experience restricted oil flow that could result in hard particles bypassing the filter and damaging critical components.
Pilot Filter Type
The pilot filters have different designs based on different location, mostly there are three:
Pilot check valve filters
The liquid flow is allowed to flow freely In one direction, while in the opposite direction, the liquid flow is cut off, but if the pressure control signal is applied to the control oil port, the forward flow can be cut off. When have the filter of the check valve,the fluid inside will be filtered.
Pilot Servo System Filters
Pilot servo valves are a close relative of the proportional valve and are based on an electrical torque motor which produces a small deflection proportional to the electrical current through its coil.
Pilot control circuit filters
Pilot control circuit filters have high working pressure, burst and fatigue requirements to withstand the duty cycle of hydraulic pilot control circuit. The primary purpose of the pilot control circuit filter is to protect sensitive valves of the equipment from contamination and excessive wear. It is high pressure filters.
Our Advantages
1. High strength, good rigidity: with high mechanical strength and compressive strength, good processing, welding and assembly performance, easy to use.
2. Uniform and stable precision: uniform and consistent filtering performance can be achieved for all filtering precision, and the mesh hole does not change in use.
Wide application environment: it can be used in – 200°c to 600°c
Cleanability: due to the excellent counter current cleaning effect of the filter surface structure, cleaning simply. (countercurrent water, filtrate, ultrasonic, melting, baking and other methods can be used for cleaning).
Media
Pilot filter with Synthetic media
Synthetic media has thinner and stronger fiber structures that minimize pressure drop . More consistent pore structures and densities increase contamination holding capacity, Synthetic media filters with their superior wire-backed media support, have an order of magnitude lower pressure drop than those using cellulose media.
Pilot control systems are continually exposed to cold start conditions and must therefore be resilient to repeated high pressure impulses. That is why we recommend Synthetic filter media is designed and validated to withstand the harshest conditions and operating environments, ensuring your equipment stays up, running and efficient.
Advantage:
l Superior particulate efficiency without added restriction
l Extra dirt holding capacity
l Superior flow fatigue resistance under high viscosity conditions
l More resilient in handling real world
Pilot filter with Cellulose media
Cellulose media has thicker fiber diameters, which close off pores and passageways for fluid flow, increasing pressure drop. But they are much more susceptible to flow fatigue failures and can expose systems to filter failure in extreme cases. Obstruction by large cellulose fibers decreases contamination holding space, reducing dirt holding capacity
Pilot filter with Dutch wire mesh
Dutch wire mesh is famous of its different diameter and mesh. Reasonable combination of the mesh and warp to achieve a square mesh can not reach the filtering density. Therefore, the mat type mesh is a fine dense mesh, but generally the warp diameter is larger than the weft diameter. The mat type mesh has reached the filtering precision that the ordinary stainless steel mesh can’t reach. Can be used in pressure filter and fuel filter.
Pilot filter with Sintered mesh
Sintered screen is generally divided into five layers structure, including four parts: protection layer, filter layer, separation layer and support layer. It is a kind of ideal filter material when the requirements for compressive strength and filtering granularity are high,Such as Pilot pump system.
FAQ
Clogged pilot filter will affect the flow of hydraulic oil, pilot control pressure, and then affect the action with or without, fast or slow. The pilot filter needs to be replaced in 500 hours.