Claims:1. A fuel filter (100) comprising :
- a housing (102)
- a filter element 106) disposed in said housing (100)
- an inlet (108) in said housing (102) through which fuel is received and said fuel is guided towards said filter element (106)
- an outlet (110) in said housing (102) to deliver fuel filtered by said filter element (106)
said fuel filter (100) characterized by:
- a first coupler (112) connectable to a pressure measuring device (302), said first coupler (112) being in fluid communication with said inlet 108 and adapted to guide a part of fuel from said inlet (108) to said pressure measuring device when connected
- a second coupler (114) connectable to said pressure measuring device (302), said second coupler (114) being in fluid communication with said outlet (110) and adapted to receive fuel from said pressure measuring device (302 to guide towards said outlet (110)
2. A fuel filter 100 according to claim 1 wherein said first and second couplers (112, 114) have spring (204) and ball assembly (206).
3. A fuel filter according to claim 1 wherein said first and second couplers (112, 114) have a passage (207) for the flow of the fuel.
4. A fuel filter according to claim 1 wherein said passage (207) remains closed when connectors (208, 209) are not connected to couplers (112, 114)
5. A fuel filter (100) according to claim 1 wherein said passage (207) opens when connectors (208, 209) are connected to couplers (112, 114) respectively thereby resulting in the passages (207) in connectors (112, 114) being in fluid communication with passages (216) in couplers (208, 209) respectively.
6. A filter clogging measurement system (300) comprising:
- A fuel filter 100 comprising a first coupler (112) and a second coupler (114) connectable to a pair of connectors (208) and (209);
- A pair of connectors (208, 209) connectable to a pair of hoses (302, 303)
- a pair of hoses (302, 303), one end of which are connectable to said connectors (112, 114); other ends connected to a pressure measuring device (304)
- a pressure measuring device (304) to detect a pressure difference between fuel entering and leaving said pressure measuring device (304).
, Description:Field of the invention:
[0001] This invention relates to the field of fuel filters. In particular the invention relates to the field of fuel filters for vehicles.

Background of the invention:
[0002] Fuel filter is a device that removes solid particles from the fuel. The filters are normally made of cartridges containing a filter paper. This filter paper has very minute pores such that the fuel flows through the filter paper but the foreign particles are blocked. As the foreign particles are blocked at the filter, slowly the filter starts getting clogged and the fuel outflow from the filter starts reducing. At some point of time, the filter element or the entire filter needs to be replaced.
[0003] The US patent application 20160332096 discloses a replaceable filter. The replaceable filter disclosed in the prior art comprises a filter housing bowl, a filter element and a coupling part. The object of the invention is to configure a replaceable filter and a filter device with a realization of a coupling between the replaceable filter and a filter head.

Brief description of the accompanying drawings:
[0004] An embodiment of the disclosure is described with reference to the following accompanying drawing,
[0005] Fig. 1 illustrates a fuel filter according to an embodiment
[0006] Fig. 2 illustrates a coupler and a connector
[0007] Fig. 3 illustrates a filter clogging measurement system

Detailed description of the embodiments:
[0008] FIG. 1 illustrates a fuel filter 100 according to one embodiment of the invention. The fuel filter 100 comprises a housing 102 forming a filter bowl 104, a filter element 106, an inlet 108 to receive fuel and an outlet 110 to deliver filtered fuel. The inlet 108 receives fuel from a fuel tank through a pump which are not shown. The fuel filter 100 according to an embodiment of the invention comprises additionally a pair of couplers 112 and 114. The couplers are referred as an inlet coupler 112 and an outlet coupler 114. The inlet coupler 112 is in fluid communication with the inlet 108 and the outlet coupler 114 is in fluid communication with the outlet 110.
[0009] Both the couplers have spring and ball assemblies which is shown in fig. 2. The spring and ball assembly form a ball valve. The ball valves normally remain closed. When a corresponding connector is inserted into the coupler, the ball valve opens providing fluid
[0010] Shows cross sections of a coupler and a connector in a blown up view.
[0011] The coupler 112 has a body 200, a pin 202, a spring 204, a ball assembly 206 and a passage 207 to allow the fuel to flow. The ball assembly 206 is movable against the spring 204. The connector 208 comprises a body 210, a pin 212, a spring assembly 214 and a passage 216 to allow the fuel to flow. When the connector 208 is connected to the coupler 112, the ball assembly 206 and the spring 204 move backwards and the pin 212 in the connector 208 pushes against the pin 202 in the coupler 112. This causes both the passages 207 and 216 to fluidly communicate. This allows the fuel to flow from the coupler 112 into the connector 208.
[0012] These connectors are similar to the LPG/propane cylinder regulators where a pin from the regulator pushes the valve on the LPG cylinder and a fluid communication is established from LPG cylinder through the regulator.
[0013] Fig 3. Illustrates a filter clogging measurement system 300. This filter clogging measurement system is simply referred as system. The system comprises the filter 100 fitted with couplers 112 and 114, a pair of hoses 302 and 303, a pressure measuring device 304. The hoses 302,303 have connectors 208 and 209 attached at one end. These connectors will be fitted to the couplers 112 and 114 respectively.
[0014] The working of the fuel filter 100 and the system 300 is explained below with the help of fig. 1 and 2 and 3.
[0015] The fuel flows through the inlet 108 into the filter bowl 104. The filter element 106 typically has minute pores through which the fuel flows into the central part of the filter element 106. As the contaminants cannot flow through the filter element 106, the contaminants are blocked in the filter bowl 104. From the central part of the filter element 106, the fuel flows to the outlet 110. The outlet 110 is typically connected to a high pressure pump and later to fuel injectors.
[0016] As the contaminants are blocked into the filter bowl 104, the contaminants start sticking to the surface of the filter element 106. The sticking of the contaminants to the outer surface of the filter element 106 results in decreased fuel flow from the filter bowl 104 to the central part of the filter element 106. This results in lower fuel pressure at the outlet 110. This results in lesser supply of the fuel to further components and then finally to an engine which is not shown. Supply of lesser fuel to the engine means less torque generation.
[0017] Over a period of time, slowly the filter element 106 gets clogged and the fuel supply at the outlet 110 is reduced to an extent where engine performance may get affected largely. To avoid such a situation, the filter element 106 needs to be replaced at regular intervals. Presently there is no provision to check the percentage of clogging of the filter element 106 unless the filter 100 is disconnected from the vehicle fuel injection system and then measurements are made on the filter 100 to check the amount of clogging.
[0018] Under the present scenario without the invention, normally the filter 100 or the filter element 106 is replaced after a certain distance is run by the vehicle. For example, for every 5000 Km or 10000 Km running of the vehicle, the filter is replaced without knowing how far the filter is clogged. In reality the filter may be still fine even after running stipulated distance. This results in unnecessary costs in replacing the filter element 106 or in some cases the entire filter 100.
[0019] The invention proposes a solution where the clogging of the filter 100 can be checked easily without disconnecting the filter 100.
[0020] During the running of the vehicle the passage 207 in the couplers 112 and 114 remain closed because of the pin, ball assembly and spring in the couplers 112 and 114. The fuel flows from inlet 108 to outlet 110 through the filter element 106.
[0021] When the vehicle is undergoing service in a workshop, the technician can check the filter for its clogging as shown in fig. 3.
[0022] The technician connects the filter 100 as shown in fig. 3. When the differential measuring device is connected to the filter 100 through the connectors 200, 202 and hoses 302 and 303, a part of the fuel starts flowing from the inlet 100 to the inlet coupler 112 and into the connector 200 then into the hose 302 and then to the measuring device, then through hose 303, through the connector 202 and to the outlet 110.
[0023] The measuring device 304 calculates the pressure difference between the inlet and the outlet of the measuring device 304. The device 304 may display the differential pressure or the % of clogging of the filter. Depending upon the clogging, the technician at the workshop may suggest whether a replacement of filter element 106 is necessary. In some cases the entire filter 100 may have to be replaced.
[0024] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.