POPPET TECHNOLOGY

Design of manifolds with optimization of flow paths and poppet valves. This technology is constantly developed by PMC Hydraulics and it can reduce the size of manifolds by more than 50 %.

Several different valve configurations are assembled directly inside the manifold. The size of each valve can be optimized in order to meet customer demands.

PMC Hydraulics Patents protects the technology. The cavity for each poppet and the seat can have a great variation of tolerances in order to achieve exactly the right solution with optimized cost.

The Poppet 

We use the poppet as a very cost effective solution in several manifolds today, and we get lower pressure drops in smaller manifolds. The poppet can be produced to fit in a hole with low tolerances, due to the simple bottom of the hole. Pressure drop can be as low as 1 bar at 200 lpm without high cost or big need for space. There are no seat with an angled surface that the poppet must hit with high accuracy and the poppet can also handle some variation of the angle. We have a high level of dirt retention with the combination of poppets and steel manifolds with Blacknite surface treatment.



Unloading valves on trucks is one example of a tough application. It is also very useful when we put several poppet very close together due to the very low pressure drop when we are bypassing several poppets inside the manifold. This is due to the shape of the poppet. We have very low leakage in the seat and we can also add different solutions under development to reduce the leakage on the side of the poppet to zero leakage. A 4/3 function can be created with four poppets and each poppet can be controlled individually in both operating directions to get a smooth acceleration and retardation of movements and smooth decompression of any captured pressure.

Proportional poppet technology


We are mostly using NG16 and NG25 valves or poppets and the flow of a NG25 poppet is approx. 450 lpm @ 9 bar pressure drop. Proportional poppets are also used in combination with steel manifolds that have Blacknite surface treatment. Proportional poppet can be used with poppet solutions to get a combination of proportional control and on/off control for cost optimization and low pressure drops.

Pilot valves for proportional poppet technology

We have some experience of proportional pilot valve solutions with compensated NG06 4/2 valve that we use and also 2/2 valves in some application. This creates several different opportunities to have really good control of functions with very low pressure drop. It is also  a rugged design for tough applications without the need for orifices and small pressure reducing pilot valves. We can control several proportional poppets with the same 4/2 pilot valve. By using four proportional poppets and two 4/2 pilot valves we get a 4/3 valve configuration.

We get a fast opening with a very quick reaction from the proportional poppet to any change in the pilot flow, compared to the flow on a big spool valve. The proportional poppet is opened quickly as it only needs to leave the seat inside the manifold.
At the same time the asymptotic curve of the proportional poppet give us a smooth acceleration and retardation. We can achieve high dynamics at low pressure drops compared to spool valves that need higher pressure drops. It is a pure hydraulic position feed back of the proportional poppet.
 
The hydraulic leakage is also very low when the pilot valve is not released to a drain port. The pilot valve flow goes to the consumer and the proportional poppet only multiplies that oil flow. Leakage is much lower than a pilot operated spool valve with proportional reducing pilot valve that have a constant leakage. 

Pressure valve technology

For pressure regulating functions with pressure chock valves, like on knifes on harvester heads, we can offer several different solutions depending on your needs. We can use poppets from traditional logic pressure valves or poppet valves to fit big poppets in small space. This can create fast chock response by reducing the movement of the poppet during a chock. The chock response can follow the pilot pressure of a proportional relief valve that is also controlling a pilot operated pressure reducing valve with some lower base pressure setting. We are also using cross over valve poppets and other valves inside the manifold as a complement to using normal screw in valves from SUN or Hydraforce.

We can modify valves for special needs with our technology and use standard mobile valves sections together in order to create the best solution for every function. Proportional poppets can be used to create proportional functions as well as proportional pilot operated spools.  Several proportional poppet can create a mobile valve manifold with several valve sections, together with digital or normal Load Sensing control.  Digital load sensing is a technology that reduce the pressure drop to almost zero by only adding the energy needed and having valve control function with very low pressure drop. Proportional pressure relief solenoids can be added with poppet inside the manifold for pressure control functions.